Green synthesis of silver nanoparticles their characterization and applicability an environmentally benign approach

Abstract

With increasing application of silver nanoparticles (AgNPs), demand for their synthesis in cost- effective and environment-friendly way is gaining importance. Over the few years great emphasis has been given to green technologies; use of biodegradable products, low waste generation, recycling of material and resource recovery. Considering this, synthesis of silver nanoparticles using a range of biological products is choice of many nanotechnology researchers today. But what if, that biological product (reducing agent) or source of silver is a waste material with no apparent industrial significance. Preparation of nanoparticles by utilizing wastes will provide sustainable procedure for silver nanoparticle synthesis, by lowering the cost of nanoparticles synthesis along with value addition to the waste biomass or material. The present study concentrates on utilization of waste products for synthesis of silver nanoparticles (AgNPs), where one or both the prime raw material (metal salt and reducing agent) are sourced from waste products. To attain this, synthesis of AgNPs was attempted using biological products in three ways, first method by using fresh leaves extract of Ficus retusa and silver nitrate (commercial AR grade). These nanoparticles were named as FRLE-AgNPs. The second method B exploits use of waste biomass of Sal (Shorea robusta) deoiled seed cake (DOC) as reducing agent in place of fresh leaves in method A, which were named as Sal-DOC-AgNPs. Sal DOC is a forest based industrial waste with no industrial significance, it was assessed for its suitability as a cheaper natural substrate for silver nanoparticles synthesis. The third method C makes use of both the prime raw material from waste sources in synthesis of silver nanoparticles, leading to resource recovery and putting minimal hazard to the environment. Here the commercial silver nitrate was replaced by silver extracted from ... newline