Engineering a dual Z-scheme copper oxide/boron carbon nitride/MXene heterojunction with tailored band alignment for high-efficiency photocatalytic degradation of refractory organic pollutants

Abstract

The accumulation of persistent environmental pollutants presents significant risks to ecosystems and human health, requiring immediate removal and effective control as a pressing global concern. Herein, we report the design and fabrication of graphitic carbon nitride (g-C₃N₄) based dual Z-Scheme heterojunction for effective photocatalytic degradation of various refractory pollutants in wastewater. Firstly, we synthesized boron-doped g-C₃N₄ via the direct calcination of melamine along with boric acid, and then coupled with Copper Oxide (CuO) and MXene via the wet-chemical method to fabricate dual Z-scheme CuO/BCN/MXene composite. The physicochemical features of the as-prepared CuO/BCN/MXene composite and reference samples were investigated via various characterization techniques. The photocatalytic degradation performance and the kinetics study for malachite green was evaluated using the as-fabricated dual Z-scheme composite and the coupling components. The CuO/BCN/MXene composite revealed exceptional photocatalytic performance by achieving 98.3 % degradation for malachite green, which is remarkably higher than the reference samples. The enhanced performance was attributed to the band gap narrowing, extended light absorption, and improved charge carrier separation. This study will provide new insights into the design and fabrication of functional nanomaterials for efficient photocatalytic degradation of pollutants and other applications.