Facile fabricated silver Pterocarpus santilinoides biochar-based inorganic–organic hybrid nanocomposite for the photocatalytic decimation of methylene blue and micro-organisms

Abstract

ABSTRACT This study investigates the photocatalytic degradation of methylene blue (MB) using an Ag-Pterocarpus santilinoides extract biochar nanocomposites (AgPSBN) followed by characterization and antimicrobial screening of the biogenic photocatalyst. The silver biochar nanocomposite was synthesized by incorporating silver nanoparticles onto the surface of biochar through a facile, biogenic, safe, cost-effective and ecofriendly method. The photosynthesized AgPSBN was porous and spherical with a size of 27 nm range. The UV-spectroscopic analysis indicated spectra bands at 648 and 667 nm for biochar and nanocomposite, respectively. The low band gap energy of 2.0 and 1.8 eV for the biochar and nanocomposite, respectively, is an indication that they can be an effective photocatalyst for the degradation of MB and for other energy applications. The percentage removal efficiency of 96.33% indicates high photodegradation ability which remained fairly constant (75%) after five cycle reuse indicating stability of the nanocomposite. The rate constant was evaluated to be 0.008 min−1. The nanocomposite indicated high inhibition zone diameter for Salmonella, E. coli, Klebsiella, and Staphylococcus aureus with inhibition zone diameters of 15, 12, 10, and 8 mm, respectively. The results strongly suggest the nanocomposite to be an effective environmental decontaminant of dyes as well as microbes.