Carbon-bismuth vanadate hybrid nanocomposite: A novel approach for enhanced photocatalytic and antimicrobial activity

The development of advanced materials along with the design of semiconductor photocatalysts is vital in enhancing photocatalytic performance while solving modern environmental or energy issues. In this work, we fabricate S-g-C₃N₄/BiVO₄ direct Z-scheme photocatalysts for photocatalytic environmental treatment, following the design concept of a direct Z-scheme photocatalyst system. Several characterizations are employed in an extensive investigation of the empirically derived chemical structures, morphologies, and photo-electrochemical characteristics. A unique, efficient catalytic material was synthesized by forming a heterostructure between BiVO₄ and graphitic carbon nitride (S-g–C₃N₄). Experiments using UV/visible reflection verified the presence of a functionalized MWCNTs/BiVO₄ binary heterojunction. The Z-type structure formed between S-g-C₃N₄ and BiVO₄ allowed for effective carrier separation, which increased photocatalytic activity. Under visible light, the optimized t-S-g-C₃N₄/BiVO₄/MWCNTS sample can remove 98 % of methylene blue (MB) in 120 min, which is significantly more effective than pure BiVO₄. Moreover, the maximum activity of 10 % functionalized MWCNTs/BiVO₄ provides the finest photocatalytic performance when the catalyst dosage is 0.02g/L. The results indicate that under optimum conditions, the degradation rate could reach 96.4 % at 90 % BiVO₄. The degradation rate could reach 97 % at 10 % t-S-g-C₃N₄/BiVO₄/MWCNTS level in the ternary nanocomposite. Similarly, t-S-g–C₃N₄/BiVO₄/MWCNTS show a 22 mm diameter inhibition zone at 250 ppm in antibacterial activity. This work presents a new way of developing new S-g-C₃N₄-based heterojunction photocatalytic materials.