A biochar-promoted V₂O₅/g-C₃N₄ Z-Scheme heterostructure for enhanced simulated solar light-driven photocatalytic activity

Abstract

A ternary biochar/vanadium pentoxide/graphite like carbon nitride (BC/V₂O₅/g-C₃N₄ denoted BC/VO/CN) composite was prepared by a simple hydrothermal method and its photocatalytic performance was investigated under simulated solar irradiation. The BC/VO/CN was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. Within the BC/VO/CN composites VO nanoparticles were highly crystalline and intertwined with the lamellas of CN, resulting in the formation of well-defined Z-type heterostructures. The photocatalytic activity was evaluated using Rhodamine B as a model pollutant. Under simulated solar (230-780 nm) irradiation the as-prepared BC/VO/CN hybrid materials demonstrated highly improved photocatalytic activity compared to CN, VO and VO/CN. The cause of the solar enhancement could be ascribed to the formation of Z-type heterojunctions between VO and CN, which promoted faster electron-hole separation and more efficient charge transfer. BC, as an electron transfer medium, accelerated the transfer of photogenerated charge carriers and inhibited their recombination.