Ag/biochar nanocomposites demonstrate remarkable catalytic activity towards reduction of p-nitrophenol via restricted agglomeration and leaching characteristics

Abstract

The rapid reduction of p-nitrophenol by sodium borohydride in presence of Ag/biochar nanocomposites is demonstrated. These nanocomposites were synthesized by deposition of silver nanoparticles on Cymbopogon citratus-derived biochar. Structural and morphological features of the nanocomposite was investigated by XRD and electron microscopy respectively. Catalytic activity of Ag/biochar was found to be remarkably higher than that of Ag nanoparticles and biochar. Effect of various reaction parameters was investigated experimentally and also scrutinized using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). According to the RSM, the maximum efficiency of conversion predicted was up to 98% of p-nitrophenol was converted to p-aminophenol when the Ag-biochar ratio was approximately 1:0.006. Furthermore, an ANN model was built which supported the accuracy of the prediction models. The catalytic activity of Ag/biochar nanocomposites which remained nearly unaltered for 5 consecutive cycles was expected to be due to restriction of agglomeration and leaching of Ag.