The Status of Green Synthesis of Silver Nanoparticles Using Plant Extracts during Last Fifteen Years

Nanoparticles (NPs) are tiny particles with their dimensions ranging between1 and100 nm. These are gaining cumulative attention owing to their vast use in different fields of applications. There are three main methods for synthesizing NPs; namely, physical, chemical and biological methods. Physical methods consume a lot of energy and time, require expensive vacuum systems and high temperatures and on top of all, they are not environmentally friendly. Chemical methods, in general, are expensive, increase the particle toxicity and perhaps harm human health and the environment. In addition, hazardous chemicals gather on the top of NPs and confine their applications. Therefore, green method is an alternative replacement to the traditional chemical and physical methods for synthesizing NPs. The existing phytochemicals, for instance in plant extracts, own a remarkably high ability for reducing metal ions within a short time comparing with other microorganisms, which require a longer incubation period. This study is concentrating on green synthesis of silver (Ag) NPs, owing to the significance of Ag NPs whose optical properties depend on their size and shape. In addition, Ag NPs possess numerous applications, especially in solar cells, water treatment and medicine. This review aims to highlight the remarkable growth of green synthesis of Ag NPs, in terms of publications, citations, active and productive researchers, targeting journals and the eminent countries in this regard. This review, also, is highlights the most utilized plants for producing Ag NPs in fourteen years; i.e., 2007-2021.This review, also, evaluating the most acceptable proposed mechanism for biosynthesizing Ag NPs using plant extracts. We believe that this review article will facilitate and brighten the road in front of researchers who want to initiate their study with the biosynthesis of Ag NPs from plant extracts.

Automated summary

Nanoparticles, with their wide range of applications, are being synthesized through physical, chemical, and biological methods. Green synthesis, using plant extracts with high reducing ability, offers an alternative to the traditional methods. This study focuses on the green synthesis of silver nanoparticles and evaluates the trends, plant sources, and proposed mechanisms.