Biogeochemical cycling of trace elements and nutrients in ferruginous waters: Constraints from a deep oligotrophic ancient lake

Researchers are increasingly required to adopt green chemistry principles in developing nanomaterials and their
applications to support a sustainable chemical industry and contribute to environmental balance. This study
presents the green synthesis of AgNPs/rGO nanocomposites using Nephelium lappaceum as both a bio-reductant
and a capping agent, alongside their characterization and application as a solid acid catalyst in benzene nitration
reactions. Graphene oxide (GO) was synthesized from graphite using a modified Hummers method, and the
AgNPs/rGO nanocomposites were prepared via an ex-situ approach. In this process, Nephelium lappaceum leaf
extract served to reduce both silver ions and GO to rGO. The results revealed that the silver nanoparticles were
spherical, with an average diameter of 6.76 nm, and were uniformly deposited on the reduced graphene oxide
(rGO) surface. Catalyst performance tests demonstrated that the synthesized AgNPs E5/rGO catalyst achieved
excellent yields and selectivity in converting benzene into nitrobenzene. Furthermore, the catalyst exhibited
remarkable reusability, with only a slight decrease in yield after five uses, while maintaining consistent selectivity toward nitrobenzene as an essential and promising chemical intermediate for many derived chemicals.