ALOE VERA EXTRACT STABILISED NANO SILVER- REDUCED GRAPHENE OXIDE NANO COMPOSITES AS VISIBLE LIGHT PHOTOCATALYST FOR OXIDATIVE DEGRADATIONS OF RANITIDINE HYDROCHLORIDE AND SODIUM DICLOFENAC IN AQUEOUS MEDIUM: A KINETIC STUDY

Nano composites of reduced graphene oxide (rGO) and silver nanoparticles (AgNps) were prepared in this work, adopting green reaction conditions. Aloe vera plant extract was used as the stabilizing agent in the AgNps system and graphite precursor has been chosen for rGO preparation adopting mild hydrothermal and sonication methods. AgNps and AgNp–rGO Nano composites are characterized using UV-VIS SPR; powder XRD, HR-TEM and FE-SEM measurements. The catalytic ability of AgNp–rGO nano composites in the as-synthesized form has been confirmed by following the oxidative degradation of the two therapeutically potential drugs such as sodium diclofenac (NaDF) and ranitidine hydrochloride (RHCl) under visible light irradiation in aqueous medium at 25°C. Reaction kinetic parameters and the oxidant peroxo monosulfate (Na₂S₂O₅) effect in presence of AgNp–rGO nano-composites as the catalyst under visible light irradiation exhibited remarkable catalytic behavior in presence of visible light for the degradation of the two drug both in presence and absence of oxidant. However presence of oxidant enhanced the speed of drug degradations with AgNp–rGO nano composites and visible light. Among the two studied drugs, RHCl degraded quickly and also, efficiently mineralized compared to NaDF. Degradation or carcinogen NDMA was not observed and the two drugs are mineralized to near completion. The results are favourable towards the use of AgNp–rGO nano composite as a potential catalyst in AgNPs employed in the treatment of drug polluted waste waters.