Keywords

1 Introduction

According to Bhainsa and D’souza [27] and Shahverdi et al. [192], nanotechnology is primarily concerned with objects, materials, and devices that have a diameter of less than 100 nm (nm). Nanomaterials have gained prominence over the past decade in medical, pharmaceuticals, agriculture, coating industries, energy production, nanostructured electrodes in batteries, communication technology devices, and food and textile industries [43, 49, 186].

Despite the many applications and benefits of synthetic nanoparticles, their synthesis is expensive and their by-products are environmental hazards [132]. Therefore, scientists and researchers are showing keen interest in green nanoparticle synthesis [153]. A green nanotechnology is an approach that uses renewable resources as opposed to physical and chemical nanotechnology [6, 117, 164], because it is less expensive, less energy-consuming, eco-friendly and causes no harm to humans [5, 10, 98, 205] (Fig. 1). Biological materials are used in the production of nanomaterials in green nanotechnology [16, 26, 63, 163, 195, 198, 205] (Fig. 1).

Fig. 1
An infographic titled green nanotechnology has a triangle. It has labels from top to bottom, safer and cost-effective, eco-friendly, and sustainable.

Main goals and materials used for green nanotechnology

The field of green nanotechnology is an important subset of green chemistry and green engineering. This minimizes power and fuel consumption wherever possible [220]. In green chemistry, there are 12 principles (Fig. 2) which are being used by Scientists, engineers, and chemists worldwide because they produce less harmful chemical products and by-products [11, 12, 124, 148]. Aside from synthesizing sustainable nanoparticles [155], green nanobiotechnology also saves raw materials, energy, and water, reduces greenhouse gases, stops adverse effects before they occur, and contributes significantly to environmental and climate protection [103, 220, 242].

Fig. 2
A vertical classification chart titled on the left green chemistry principles with the classified list on the right from the top to bottom labeled prevention, atom economy, less hazardous chemical syntheses, designing safer chemicals, etcetera.

Green chemistry principles for green nanotechnology

Figure 3 shows green nanotechnology applications which may involve in cosmetics, nanofabrication, bioengineering, energy production, green building constructions, medicines and drugs, nanobiotechnology, optical engineering, agriculture, food and coating industries, etc. [220]. To make a conclusive assessment, green nanotechnology requires a complete process assessment like any other industrially manufactured product [18, 25].

Fig. 3
A circular block diagram titled green nanotechnology at the center. The applications are agricultural applications, biomedical and pharmaceutical applications, energy applications, etcetera.

Applications of green nanotechnology in various sectors

To eliminate or greatly reduce pollution, as well as to foresee and lessen the environmental repercussions of the manufacturing chain, green nanotechnology relies on the design and use of non-toxic nanomaterials [104, 204]. Other applications of green nanotechnology include photocatalysis, solar cells, fuel/bio-fuel cells, and cleaner production [78, 96, 168]. Furthermore, green nanotechnology applications include the conversion of diesel soot into carbon nanomaterials which can be used to recycle industrial wastes [30, 142]. In this chapter, we have elaborated the applications of green nanotechnology in different fields.

2 Green Nanotechnology and Its Applications

According to Anastas and Warner [11, 12] and Karn and Bergeson [112], green nanotechnology aims to develop and produce goods that are environmentally sustainable. Its primary objective is to inform readers about nanoparticles and their numerous useful and potentially harmful properties. Furthermore, negative impact on health and ecosystem can be reduced through nanotechnology, which has a wider societal benefit. Thus, green nanotechnology contributes from selection of raw materials to safer release to the environment [202].

2.1 Green Nanotechnology in Biomedical Applications

Treatment and prevention of many diseases could be revolutionized by biomedical nanotechnology [143]. Opportunities in the near future include the discovery of infectious microorganisms and viruses and the detection of molecules that are associated to the development of many diseases like cancer, diabetes, and neurological diseases. Nanoparticles with the ability to react to external stimuli would be useful in the delivery of cancer medications [7, 20, 47, 64, 88, 126, 134, 167, 174, 183]. In addition to medical implants, biomaterials can be used to create scaffolds for grafts. Non-specific macromolecules could be prevented from adhering to nanostructured surfaces created by this method. Biocompatibility of materials can be improved by controlling surface characteristics at the nanoscale.

There is currently a paucity of information on the pharmacological dangers linked with this technique, despite it is being widely available. Structures can take on entirely new features when scaled down to the nanoscale. A particle’s aggressive or kidney-damaging actions appear to be best predicted by its minuscule size, which is mostly determined by its chemical composition. All medical technology applications (Fig. 4) must have a risk management plan in place. Afterward, we will take a look at some of the possible medical applications of nanomaterials and nanoparticles. Biocompatibility, implants, cardiology, cancer [42, 102, 158, 199], and theranostics are just a few of the many diagnostic and therapeutic uses for “nanorobots” and other forms of nanomedicine. Last but not least, the dangers to human health and ethical issues are discussed in detail [170, 171, 175].

Fig. 4
A block diagram titled biomedical applications at the center, with a list of applications from the top in a clockwise direction, are drug delivery, immuno-sensing, biosensing or bioimaging, therapy, diagnosis, and antimicrobial effects.

Biomedical applications of green nanotechnology

In the field of drug delivery, nanomaterials and nanoparticles are useful tools. There are a number of nanomaterials that can be used to destroy cancer cells because of their unique mechanical, electrical, electronic, thermal, and optical properties [176, 202]. Due to their extraordinary size, optical and electrical capabilities, and comparatively low cost and ease of manufacturing, quantum dots have found utility in medical imaging applications. Physicochemical and biological properties of dendrimers can be enhanced through their small size (5 nm) and can pass via cell membranes, tissues, and vascular pores. Nanomaterials can be used in protein, RNA, and DNA structure detection by using fluorescent markers for resonance imaging improvements [194, 202].

2.2 Agricultural Applications of Green Nanotechnology

The food and feed sectors have always relied on agriculture for supply and generation of raw materials. Population growth and the scarcity of natural resources (such as farmland and water) encourage agricultural development that is more profitable and environmentally friendly [109, 149, 236].

It is essential for the elimination of poverty and hunger that agricultural development takes place. As a result, we must take a risk in order to advance agricultural growth. This global mainstream has people living in poverty and in rural areas where agricultural expansion is less effective [166]. More recently, food and nutrition security have become a central part of cutting-edge scientific research. The objectives of agricultural development should include factors such as social inclusion, health, climate change, energy, ecosystem processes, natural resources, and good governance, [236]. As a result, sustainable agriculture increases the likelihood of eliminating poverty and hunger in the real world [213].

Incontrovertibly, the future of agriculture depends on the implementation of cutting-edge techniques like nanotechnology. In agricultural systems, the increasing use of smart nanotools has the potential for revolutionizing agricultural practices and reducing or eliminating their environmental impact [133, 189].

Nanotechnology plays a crucial role in sustainable agriculture by regulating nutrients and productivity via water quality [91, 149] and pesticide monitoring [165]. A general assessment of the health and environmental hazards posed by nanomaterials is impossible due to their wide range of properties and activities [165]. In agriculture, nanotechnology research also influences sustainable development. Soil fertility can be maintained, agricultural resources can be effectively managed, drugs can be effectively delivered, and this technology has proven to be effective. Risk assessments are continuing in several fields, including those dealing with biomass and agricultural wastes, food processing and packaging, and more [76]. It has recently become common practice to use nanosensors for environmental monitoring in agriculture because of their robustness and speed [106].

Microorganisms use nanoparticles to direct catalyze the destruction of toxic chemicals and waste products, making the process more effective. Hazardous compounds and toxins are broken down by organisms in agricultural soils and waters. Bioremediation (using beneficial microorganisms), phytoremediation (using plants), and mycoremediation are other commonly used terms (fungi and mushrooms). As a result, bioremediation can be used to safely and effectively remove heavy metals from soil and water using microorganisms [60]. As a result, agricultural bioremediation encourages long-term approaches to remediation that restore soil to its natural state. Consider using the nano–nano interaction to improve agricultural soil sustainability by removing potentially harmful components [60, 106]. Microbes are undeniably important in sustaining soil health, the environment, and agricultural productivity [145]. As a result, the introduction of modified NPs (chemical or green) should constantly be evaluated on a regular basis to ensure environmental stewardship in the agricultural sector (Fig. 5).

Fig. 5
An infographic with four schematic illustrations at the four corners with the title at the center, application of nanoparticles on sustainable agriculture.

Applications of green nanotechnology on sustainable agriculture [166]

Although nanofertilizers (Table 1) have been widely available on the market in the past decade, the majority of agricultural fertilizers have not been developed by major chemical companies. Several types of nanofertilizers are available, including “nanozinc, silica, iron, titanium dioxide, core–shell quantum dots, and gold nanorods.” Its quality is further enhanced by the fact that it was released under strict supervision. Over the past decade, researchers [59, 239] have focused on the potential benefits of using metal oxide nanoparticles in agriculture. As a result of zinc deficiency in alkaline soils, agricultural productivity has been limited [180].

Table 1 List of nanofertilizers and their composition [166]

In the near future, nanomaterials will be used to protect crops and produce food. In agricultural fields, NPs play a crucial role in controlling insect pests and host pathogens [121]. The development of a novel nanoencapsulated pesticide formulation with slow release properties has been reported recently [29]. Increasing the effectiveness of active ingredients by preventing their premature degradation for longer periods of time is the primary way to achieve crop protection due to the development of environmentally friendly nanoencapsulated insecticides [160], which has resulted in a decrease in pesticide doses and human exposure. There is a growing interest in developing non-toxic and environmentally friendly pesticide delivery systems in order to improve global food production and minimize the adverse effects on the environment [29, 55, 90, 110].

The quality of chemicals delivered to biological processes can be improved using nanoencapsulation, which is similar to microencapsulation. Nanoscale pesticides have recently been marketed as “microencapsulated pesticides” by some chemical companies [89]. Microencapsulated pesticides from Syngenta (Switzerland), “Subdew MAXX Karate ZEON, Ospreay’ Chyella, Penncap-M, and BASF” are all suitable for use at the nanometer scale. “Primo MAXX, Banner MAXX, and Subdue MAXX” are all Syngenta products sold in Australia. These are nanoscale emulsions, despite the fact that they are commonly referred to as microemulsions in the marketplace. As a result, the distinction between microemulsion and nanoemulsion is kept as thin as possible. Agrochemicals and organic NPs are commonly formulated using this method [89].

Biosensor development will continue to be influenced by nanotechnology because of its many advantages. The unique properties of nanomaterials can greatly enhance the performance and sensitivity of biosensors [77], but it has also prompted the development of numerous new transduction technologies [190]. Utilizing nanomaterials streamlines the development of numerous (bio)sensors, including nanosensors and other nanosystems essential for biochemical analysis [77, 190, 221]. Mycotoxins, which are present in many different foods, can be detected fast and easily with (bio)sensors help [190].

2.3 Green Nanotechnology in Food Industry

Future food production will be significantly affected by nanotechnology. Food additives and food packaging are the primary uses of nanoparticles in the food industry. The most important differences between the two types of packaging are that additives can be used to enhance the flavor or texture of food, while packaging can help to prevent rotting and increase the quality of the product by minimizing gas flow during packaging [157].

Antimicrobial food contact surfaces, including containers, cutting boards, and freezers, are now being manufactured commercially using nanotechnology [210]. Sugars and proteins serve as a target recognition group for nanostructures used in food biosensors [38]. Foodborne pathogens and other contaminants can be detected and tracked using these biosensors. Environmentally protective encapsulation systems can benefit from nanotechnology as well. As a flavor and an antioxidant, it can be used in the formulation of food products as well [105]. While reducing the concentration of these substances, the goal is to increase their activity and efficiency [95]. Nutraceutical delivery systems and controlled release mechanisms are increasingly being investigated as the practice of adding new ingredients to foods [135]. All food production and processing could benefit from nanotechnology, but many of the techniques are prohibitively expensive or impossible to put into practice commercially. New functional materials and food formulations, as well as micro and nanoscale processing, product development, and storage development, are all areas in the food industry that can benefit from nanoscale techniques [156].

A reduction in the risk of certain diseases, such as cancer, may be one of the physiological benefits of bioactive chemicals present in some foods. In the gastrointestinal system, nanotechnology is capable of improving transport characteristics, solubility, and long-term absorption by reducing particle size [41]. Ingredients like “omega-3 and omega-6 fatty acids, probiotics, prebiotics, vitamins, and minerals” are used in food nanotechnology [223]. A number of nanoparticles have been developed to ensure the safety of food products, including “micelles, liposomes, nanoemulsions, biopolymeric nanoparticles, and cubosomes” [71, 131, 152, 232]. Nanotechnology’s applications in the food industry are illustrated in Fig. 6.

Fig. 6
4 parts. 1. Heat transfer, nanoscale engineering, nanobiotechnology, and molecular synthesis. 2. Nanoparticles, nanoemulsions, nanocomposites, and nanostructured materials. 3. Applications are processing, product, food safety, and biosecurity which divides into nanosensors and nano detectors, and materials. 4. Delivery, formulations, and packaging.

Applications of green nanotechnology in food processing and technology [171]

As of today, most of the nanotechnology research is concentrated in the fields of electronics, medicine, and automation. The topic of nanoparticles being unintentionally or purposefully introduced into food is a common one when discussing nanotechnology and food [39, 177, 216, 219]. Risks and benefits of using nanoparticles are that very little is known about their bioaccumulation and toxicity [97].

There are numerous applications for the incorporation of nanoparticles into food contact materials. TiO2 pigment nanoparticles remain UV absorbent after becoming transparent. The absorption of UV radiation must be minimized in transparent wraps, films, or plastic containers. By using nanoclays, gas diffusion can be reduced and shelf life can be extended.

Additionally, food preservation is critical to the food industry’s success. When exposed to foodborne pathogens, nanosensors, such as a system composed of hundreds of fluorescent nanoparticles, can fluoresce in a various forms of colors, allowing in order to detect food spoilage. By using nanosensors, it is possible to detect pathogens in hours or minutes rather than days [28], given the vital necessity of time in food microbiology. In packaging materials, nanosensors can be used as “electronic tongues” or “noses,” detecting the compounds that are emitted when food is spoiled [82, 125]. Microfluidic nanosensors [17] can also be used to detect infections quickly and accurately in real time and with great sensitivity.

Devices with nanometer- to millimeter-scale moving parts, known as NEMS (nanoelectromechanical systems), are already being employed in the food analysis sector as development tools for food preservation technology. One of the numerous benefits of using micro and nanotechnologies (MNTs) in food technology is the ability to carry about instruments that respond quickly, are inexpensive, and can communicate intelligently at multiple frequency levels. MNTs are ideal for food safety and quality since they are able to identify and manage any contamination packing or storage conditions [34].

The food industry’s nanotechnology R&D is heavily focused on food packaging and regulation [31]. In spite of public concerns about nanotechnology, the food packaging industry continues to develop products utilizing this technology. According to Fletcher [75], the global market for food and beverage packaging nanotech products will reach $20.4 billion by 2010. Despite increased marketing, researchers have found success in the realm of food and food products by applying nanotechnology [39]. Due to concerns around prospective food labeling and consumer health, nanotechnology has not yet been applied to the realm of food. Researchers in the Netherlands have developed nanopackaging, which detects when food is going bad and releases a preservative to extend its shelf life. One of the most fascinating emerging trends in the food sector is the use of nanopackaging to both improve food safety and lengthen its shelf life. The world has already adopted other, less dramatic (but more useful) innovations in nanopackaging [17, 32, 33].

2.4 Green Nanotechnology in Environmental Applications

Nanomaterials have been utilized to clean contaminated water, which includes heavy metal ions, organic and inorganic solvents, and a wide range of microorganisms [14, 123]. The affinity of nanomaterials for non-degradable pollutants has led to the development of nanomaterials for environmental cleanup and site remediation. Adopting eco-friendly building principles can reduce or eliminate environmental pollutants [8]. All forms of water contamination can be effectively removed by using nano-adsorbents such as “clay, zeolites, metals, metal oxides, polymeric membranes, porous nanofibers, and zero-valent iron” [188, 224]. As part of their irradiation-based degrading and mineralizing process, AOPs rely on semiconductor-based photocatalysts (natural and artificial) that are ecologically safe [215].

Nano-treatment reduces the amount of pollutants in the environment compared to earlier cleanup procedures [22]. Health and environmental problems can be prevented, reduced, and mitigated using nanotechnology [99]. As nanotechnology advances in environmental protection technologies, new solutions will be available to manage and remove pollutants in the atmosphere, groundwater supply, and surface water. Traditional techniques of cleansing will also benefit from this advancement [193].

In situ treatment with nanotechnology is a time and money-saving alternative to traditional methods [58]. Treatment of polluted areas with nano-based remediation technology can cut costs, speed cleaning, and virtually remove the need to dispose of or treat contaminated soils [85, 86]. Advanced research and development are looking into the possibility of using nanomaterials to efficiently filter out environmentally harmful contaminants [203, 237]. Recently, many nanomaterials, such as “nanoscale zeolites, metal–metal oxides, carbon nanotubes, dendrimers, and metal-polymer doped nanoparticles,” have been studied for potential applications in nanotechnology [22, 161]. Nanomaterial oxides used on site, in addition to surface and groundwater cleanup, are effective for cleaning up non-aqueous phase fluid (NAPL) spills from subterranean oil tanks [50, 65, 94, 179].

Environmentally friendly products and processes can be developed using nanotechnology, which is central to green nanotechnology [62]. According to Maksimovic and Omanovic-Miklicanin [140], these technologies are primarily designed to be environmentally friendly and have a minimal impact on human health and the environment. Wastewater treatment using catalysts, adsorbents, and membranes based on nanotechnology is more environmentally friendly [214]. A high surface-to-volume ratio (SVR) makes nanoparticles promising for use in environmental purification and restoration [57]. Many researchers are working to create novel nanomaterials with enhanced selectivity, efficiency, and effectiveness for use in wastewater treatment. Nanotechnology for water treatment is the key to ensuring the safety and cleanliness of water supplies worldwide. Table 2 summarizes the nanotechnology applications which can be used to treat wastewater.

Table 2 Applications of green nanotechnology in soil and water treatment [119]

Nanotechnology-based remediation techniques are safer, more cost-effective, and more effective than conventional methods. Pollutant sensing and detection, cleaning, and pollution control are all potential applications for nanomaterials [115]. The nanomaterial’s high SVR makes them ideal for water treatment and purification. Semiconductor nanomaterials are layered on top of conventional membrane treatments for purification and to create unique photocatalytic membranes [122]. Nanofiltration, photocatalytic processes, and adsorption are some of the methods used to solve wastewater treatment problems [13, 182].

Nanoparticles, nanomembranes, and other nanomaterials can be used for the detection and removal of a wide variety of chemical and biological pollutants [2, 9, 118, 120, 154]. Both filtration and photocatalysis can be accomplished with the use of membrane processes and nano-based materials [3, 141]. The use of environmentally friendly wastewater treatment solutions has become increasingly important due to sustainability concerns. Through the use of green chemistry to synthesize nanomaterials for environmental cleanup, hazardous waste generation can be reduced and toxic end products eliminated.

2.5 Green Nanotechnology in Renewable Energy Generation

The primary focus of this research is to develop green chemistry-based nano-enabled solar cells. Solar-absorbing polymers such as quantum dots, titanium dioxide, and cadmium telluride (CdT) are among them [92]. Compared to existing solar cells, these nano-based solar cells are much more cost-effective [222]. The effectiveness of solar cells is being improved by a number of efforts in this area. For the design of environmentally friendly products in the future, other techniques such as the deposition of nano-crystals, the use of nanowires, and the development of a very durable lamination layer that covers solar cells are also being investigated [150]. Energy storage devices for renewable energy have also been developed using nanotechnology research. The performance and cost benefits of solar devices based on nanotechnology are significant [212].

2.6 Green Nanotechnology in Green Building Constructions

Nanotechnology is an important technology in the field of green manufacturing as it has the potential to contribute to environmental sustainability. The services provided by green building professionals, engineers, and architects are directly affected by the innovations [51, 52]. Due to advances in nanotechnology, suitable materials with unique properties are now available. In the past, designers had to rely on a limited number of standard materials. The design and construction of buildings will be directly affected by nanotechnology due to its impact on information technology, sustainability, and the development of novel materials and uses [129]. The value chain established by nanotechnology in building design and construction is depicted in Fig. 7. This value chain was developed using a comprehensive strategy and deep integration of state-of-the-art technologies via nanotechnology in green building design. Considerations of aesthetics, utility or functional performance, life-cycle cost, and sustainability from the user’s point of view are at the heart of the most realistic and practical applications of nanotechnology [53].

Fig. 7
A chart illustrates the value chain in the building construction and design process through nanotechnology. The chart is headed at the top by construction and building supported on either side by information technologies on the left and sustainable applications on the right, each interconnected with the relevant list below.

Value chain created by nanotechnologies [51]

All aspects of the project, material or product, and service must be questioned in a green building project. Teams working on buildings are urged to employ life-cycle thinking when calculating the environmental implications of the structure as a whole, rather than just its components. “Life-cycle assessment (LCA) and life-cycle costing (LCC)” are two methods used to determine total cost of ownership (TCO). Fuel, installation, operation, maintenance, disposal, financing, and replacement are all parts of LCC, which is used to evaluate each proposed technology and method for the project’s environmental and economic viability [46].

As part of the green building lifecycle, it is essential to maximize the use of materials and energy. Green building design ideally has a fully closed-loop lifecycle. The objective is to minimize garbage leftover after a product has served its useful purpose. To ensure long-term viability, the material must be durable [54]. To last, a material must be structurally and aesthetically strong. There are various many advantages to designing for disassembly. It helps to increase the life of building components and systems, making them easier to repair or modernize. It also helps in recycling construction materials and rebuilding entire parts. Conventional energy sources such as “coal, oil and gas” have limited supplies and emit greenhouse gases into the atmosphere. “To improve our quality of life while preserving the planet’s ability to support us, we must transition to renewable energy and design for energy efficiency.” Reducing dependence on finite fossil fuel supplies and avoiding the effects of air pollution and climate change are just two of the environmental and social benefits of renewable energy [54].

Eco-friendly buildings are more efficient than buildings that are not. Environmentally friendly management refers to an organization that aims to reduce costs and improve operational efficiency by implementing sustainable practices in its buildings. The total cost of the facility is explained as follows: Only 10% of the time is spent on the building; 90% of the time is spent on building operating and maintaining the facility. Clearly, a great way to reduce costs and increase revenue is to have tight control over facility operating costs. A large portion of the company’s budget is paid for fuel and other necessities. The organization/company can only achieve sustainability if it provides a work environment free of harmful air, chemicals, and materials [225].

Nanotechnology has the potential to greatly improve sustainability in a variety of ways, including material and energy efficiency, process efficiency, and productivity. Titanium dioxide (TiO2) nanoparticles are being tested, for instance, by scientists in Hong Kong and Japan as a means of reducing air pollution [54]. Up to 90% of nitrogen oxides were removed in the experiments, suggesting that dusty cities could face major health risks by embedding these nanoparticles in roads and structures. TiO2 is also used by the Japanese company Toto as a coating for the manufacture of tiles. Indoor air quality can be improved with the use of certain nanomaterials. This is possible by coating the concrete with a thin layer of TiO2 nanoparticles that consume pollution. This catalytic action degrades pollutants in contact with the surface [54].

Surface applications add new functionality to the texture of new materials, improving the quality of structures. Many companies are experimenting with nanotechnology to improve the properties of various materials. Currently, materials and coatings improve the health and safety of buildings and homes, as well as increase their energy efficiency by storing the sun’s rays for later use. Nanomaterials are also used in air quality monitoring, air filtration, and energy-efficient air-conditioning systems [54].

2.7 Green Nanotechnology in Coating Industry Applications

Coating technology is widely used in many areas of our daily lives. Coating materials are manufactured for a variety of purposes, from food and pharmaceuticals to wearable and consumer goods, industry and machinery, and auto and construction components [84]. A film of coating material is often applied to the surface or bulk material of an object to protect, enhance, or provide additional capabilities and properties. This can be achieved by using coating technologies that help to protect surfaces from degradation caused by exposure to environmental factors such as moisture, UV rays, as well as preventing or reducing fouling and biofouling [241]. They can reduce chemical and structural degradation as well as wear and tear. Antimicrobial properties used for self-cleaning properties, such as super-hydrophobicity or super-hydrophilicity, are added to surfaces by coating methods [84]. Also, in food and medicine, functional coatings can be used to mask taste and smell, protect and stabilize the physical environment, and release specific amounts into the body. As a result of the strong demand for functional coating materials and technologies resulting in economic value, more time and effort are devoted to research and development [241].

Functional coating technology mainly focuses on the development of coating materials and deposition processes for various applications. Inorganic nanoparticles and organic polymers can be used as functional coating materials based on their specific properties and functions [81]. There has been a meteoric rise in the creation of novel nanotechnology-based coatings in the last few years.

Nanotechnology has led to new advances in coated materials such as antifouling, anti-reflective, and fire-retardant coatings [101, 138, 227] (Fig. 8). Several silicone resin polymer foam composites have been used, including “silicone resin polymer foam composites [226], polydimethylsiloxane/graphene foam nanocomposites [35], water-based clay/graphene oxide nanoribbon networks [234] and composites of graphene oxide and melamine sponge” [36]. Tang’s team created several types of fire-proof coatings and alarm coatings based on the GO Network [37, 229]. However, Lejars et al. [128], Banerjee et al. [19], and Detty et al. [56] provide in-depth studies of the use of sol–gel technology to antifouling coatings, surface design, and alterations to thwart biofouling growth. Raut et al. [169] summarizes anti-reflective coatings made of silicon and TiO2, functionalized polymers, and gallium as well as their production methods. Coating materials can benefit from the introduction of nanotechnology, which provides new features and functionalities that can be used to improve the performance of coating materials.

Fig. 8
An flow diagram illustrates coated materials through green nanotechnology in 2 parts. The first part has the path of green synthesis materials for nanocoatings leading to the second part with the list in 2 columns of applications like U V lights protective coatings, anti-COVID coatings, etcetera.

Green nanotechnology in coating applications [84]

Generally, functional coating materials based on nano-composite chemistry are synthesized and then applied to surfaces [24, 151, 243]. Instead, deposition techniques are used to create or change the surface structures of coating materials at the nanometer level. There are several methods of coating application, including spraying and drop-casting, as well as dip coating and cast coating [15, 73, 93, 116].

In contrast, functional coatings play a crucial role in green construction. The most common type of coating is undoubtedly paint, which provides a variety of benefits including aesthetics and solar reflection [201, 209]. Other functional coatings such as self-cleaning, solar filtering, light and temperature control can be applied to external aspects of structures such as walls, ceilings, and windows [209].

Using nanotechnology for green building design and construction to improve properties and performance. Some examples are photocatalytic coatings, coatings that reduce surface solar radiation, and PCM coatings. These functional coatings are being developed by researchers around the world to reduce the carbon footprint of green building components. As a result of the self-cleaning and anti-icing capabilities of superhydrophobic coatings applied to building exteriors or civil engineering materials, additional resources and efforts are not required to successively clean, defrost, or repair worn or torn and cracked building components [228]. In addition, they contribute to the breathability of the wall, reduce thermal conductivity, and improve the resilience of the wall to biological agents such as bacteria [238]. As a result of the large surface area covered by water and the photocatalytic degradation of dirt and impurities under sunlight, the self-cleaning property reduces the effort and resources required for cleaning [159]. The anti-microbial [130] and moisture-controlling properties [61] of the hydrophilic coating have also been described. Solar reduction coatings, on the other hand, limit heat absorbed from the sun by using less energy to maintain a comfortable temperature inside the building [240]. Effectively reducing the temperature inside a building using phase change material coatings is a great way to save money on energy costs [111].

2.8 Green Nanotechnology in Cosmetic Applications

As defined by the Food and Drug Administration (FDA), cosmetic products are products designed “to enhance, promote, or alter the human body or any part thereof”. A cosmetic is any item used to enhance the skin’s natural beauty and cleanliness [83]. The worldwide demand for cosmetics has climbed by 4.5% each year in the twenty-first century, with yearly growth rates ranging from 3.0 to 5.5% [67, 181].

In the cosmetics industry, a product is considered to be “cosmetic” if it contains physiologically active substances that have a therapeutic impact on people [67, 136, 181]. Cosmetics possess bioactive components with quantifiable therapeutic properties that make them an excellent choice between pharmaceuticals and cosmetics. These ingredients are useful for treating a wide variety of issues, such as skin aging, hair loss, dryness, pigmentation, dark spots [114, 136] (Fig. 9).

Fig. 9
A circular infographic headed by, nanotechnology-based cosmetic formulat, and the relevant applications like beauty care, dental care, hair care, skin care, deodorants, and sunscreen.

Green nanotechnology in cosmetic applications [185]

As one of the most promising new technologies of the twenty-first century, nanotechnology is closely monitored by the cosmetics industry. It is possible to improve the delivery of bioactive chemicals with the use of nanotechnology in nanocosmeceutical formulations [100, 114]. Nanoparticles of cosmetic compounds can be prepared using this technology, which results in increased production efficiency and better skin damage repair due to the compounds’ smaller size and higher absorption rate [197].

It has been shown that various types of nanoparticles can be used to enhance cosmetics, including “liposomes [206], niosomes [231], solid lipid nanoparticles [208], nanocapsules [178], micelles [235], dendrimers [147] and metal nanoparticles [137].” This process allows us to develop fragrances with extended longevity, cosmetics with enhanced UV protection, and effective anti-aging remedies (Fig. 9). The use of nanocarriers can reduce the size of bioactive ingredients in cosmetics, increasing their therapeutic potential [136].

The use of micellar nanoparticles in skin washing products is widely regarded as one of the most significant and cutting-edge breakthroughs in the field of cosmetics based on nanotechnology [40, 66, 79, 146]. Using nanotechnology, lipophilic bioactive ingredients can be incorporated into cosmetic formulations that possess a variety of physical and chemical properties. Nanoparticle size, encapsulation efficiency, and fabrication cost of micellar nanotechnology are superior to liposomes and niosomes [127, 207]. Many global and local cosmetics companies use micellar nanotechnology in their cleanser formulations to claim that their micellar nanotechnology-infused facial cleanser is the most effective on the market. With micellar nanotechnology, these brands have performed well. These cosmetics can benefit from using this process.

2.9 Green Nanotechnology in Textile Industry Applications

The textile industry is a leading user of nanotechnology, and numerous nanotextiles—including a wide range of consumer goods that employ nanoparticles—are currently on the market [1, 48, 68, 108, 113, 173, 187, 233]. Some of these high-tech textiles have built-in safety characteristics like being resistant to fire, dirt, water, and even ultraviolet light [4, 69, 70, 230]. The possibilities for textile applications are being broadened by the use of nanocoatings and nanofinishings [21, 74, 87, 107, 162]. High-performance textile coatings made from different nanomaterials can help a lot [23, 139, 172, 191, 196, 218]. Recent research on textile modification and characterization has focused on plasma and nano-pretreatment [200]. Fabrics created with nanotechnology are displayed in Fig. 10. Nanomaterials are able to offer greater functionality in textiles, despite their small size and large surface area. Commonly used carbon-based nanomaterials in textiles include “metal oxides, metal and nanoclay nanoparticles, core–shell nanoparticles, composite nanomaterials, hybrid nanomaterials, and polymeric nanomaterials such as graphene, carbon nanofibers, and carbon nanotubes.”

Fig. 10
A circular schematic infographic illustrates the applications of nanotechnology in the textile industry. The applications are water repellence, wrinkle resistance, computing, sensors, etcetera.

Applications of nanotechnology in textiles [184]

3 Limitations of Green Nanotechnology

A new field of study, green nanotechnology, has its limits and limitations to overcome. The ACS Green Chemistry Institute (ACS GCI) reports on the main problems of green nanotechnology: Managing issues related to the toxicity of nanomaterials must also overcome economic and technical challenges. (1) Nanomanufacturing processes are subjected to regulatory procedures, (2) implementation of scale-up methods, (3) cycle of life aspects.

Green and sustainable development must take into account all of the above factors. Although green nanotechnology can reduce pollution and improve the environment, the expense and dangers of nano-based product manufacture are important limits. However, even if green nanotechnology has made progress, the level of sustainability has always been a challenge. However, upstream processing of green nanotechnology-based materials remains an important concern [44].

Green nanoproducts are now being investigated for their synthesis and application, although very few products have been developed in the commercial market so far [45]. The consensus is that the commercial potential of green nanotechnology is expected to be fully understood within a few years.

4 Conclusions

Using nanotechnology, we can solve the world’s most serious issues. The term green nanotechnology refers to a technology that has a green advantage, as its name implies. Green chemistry is being thought about more and more in the context of nanotechnology because it provides a framework. Many benefits have been found through the studies, but some drawbacks and issues also need to be addressed. By using green nanotechnology, we can help solve the environmental crisis and promote sustainable development. For nanotechnology to be environmentally sustainable, life-cycle considerations must be included in the analysis of nanoproducts. New nanoproducts created through the nano-manufacturing process undergo life-cycle assessments before being released into commerce to fully assess their potential contribution to green development. However, there is always opportunity for development in bringing green chemistry ideas to nanotechnology.