Greener and Sustainable Trends in Synthesis of Organics and Nanomaterials

Abstract

Trends in greener and sustainable process development during the past 25 years are abridged involving the use of alternate energy inputs (mechanochemistry, ultrasound- or microwave irradiation), photochemistry, and greener reaction media as applied to synthesis of organics and nanomaterials. In the organic synthesis arena, examples comprise assembly of heterocyclic compounds, coupling and a variety of other name reactions catalyzed by basic water or recyclable magnetic nanocatalysts. Generation of nanoparticles benefits from the biomimetic approaches where vitamins, sugars, and plant polyphenols, including agricultural waste residues, can serve as reducing and capping agents. Metal nanocatalysts (Pd, Au, Ag, Ni, Ru, Ce, Cu, etc.) immobilized on biodegradable supports such as cellulose and chitosan, or on recyclable magnetic ferrites via ligands, namely dopamine or glutathione, are receiving special attention. These strategic approaches attempt to address most of the Green Chemistry Principles while producing functional chemicals with utmost level of waste minimization.

Room temperature synthesis of biodiesel using sulfonated graphitic carbon nitride

“…The Sulfonated graphitic carbon nitride (Sg-CN) has been designed and synthesized via sequential calcination333435 and sulfonation of urea (Fig. 1).…”

“…Engaged in the development of sustainable methods and converting waste products into valuable chemicals3031323334, herein, we report the use of sulfonated graphitic carbon nitride (Sg-CN) as a benign and cost effective organo-sulfonated heterogeneous acid catalyst for the synthesis of biodiesel.…”

Green Synthesis: Nanoparticles and Nanofibres Based on Tree Gums for Environmental Applications

“…the environmentally benign solvent medium (water and ionic liquid-based green solvents) for the synthesis of NPs; gum acts as reducing agent due to the presence of many functional groups in the gum structure (-OH, -COO-, -CO, and CH 3 CO-) and gums are non-toxic and biodegradable materials for the stabilization of NPs. However, even today, many studies have reported the use of toxic solvents such as organic solvents, and toxic, highly reactive and environmentally and biologically risky reducing agents such as hydrazine, sodium borohydride and dimethyl formide, and capping agents such as EDTA, triethanolamine and tetraethylammonium bromide, which are known to bio-accumulate in the environment and are persistent pollutants, which may have ecological or human health risks, used for the synthesis of NPs [8][9][10]17]. …”

“…Nanoscale filtration techniques, the adsorption of pollutants on nanoparticles and the breakdown of contaminants by nanoparticle catalysts are the major applications of nanotechnology in the clean-up of contaminated water [8][9][10]. The advantages of electrospun nanofibre membranes are that they can offer both adsorption and filtration characteristics.…”

“…Green nanotechnology, the combination of nanotechnology and the principles and practices of green chemistry, may hold the key to building an environmentally sustainable society in the near future. Nanomaterials also offer applications to prevent pollution by utilizing certain catalytic processes to create less waste production, sense pollutants in water and the environment, destroy harmful bacteria and viruses and create clean water and a clean environment [8][9][10]. Green chemistry is a set of principles or practises that encourages the design of products and processes that reduce or eliminate the use and generation of hazardous substances [11][12][13][14].…”