Direct Z-scheme heterojunction of BiVO4 microsphere/g-C3N4 nanosheets for the efficient photocatalytic degradation of Rhodamine B

Abstract

Degrading dye waste using inexpensive synthetic photocatalysts is intriguing since it provides the dual advantage of treating water and managing waste simultaneously. There is considerable interest in the construction of heterojunctions for their efficiency in using solar energy for the degradation of wastewater contaminants and enhancing the solar conversion efficiency. Herein, BiVO₄ microspheres and 2D g-C₃N₄ nanosheets were used to synthesize a direct Z-scheme BiVO₄/g-C₃N₄ heterojunction through a hydrothermal calcination approach. The distinct 0D/2D intimate contact heterostructure displayed a high interfacial area and broader visible-light absorption range together with high photoexcited charge pair mobility. Optimizing the content of the BiVO₄ microspheres in the heterostructure led to the maximum efficiency for the visible-light photodegradation of rhodamine B (RhB), which was about 12.5 and 2.4 times higher than that for pure BiVO₄ and g-C₃N₄, respectively. Moreover, the quenching effects of various scavengers demonstrated that ˙O₂⁻ and ˙OH radicals were the principal active species responsible for ameliorating the photocatalytic performance for RhB degradation. The demonstrated strategy for boosting the photocatalytic performance with Z-scheme systems may help the advancement of high-performance photocatalysts for sustainable and efficient pollutant degradation and energy applications.