An investigation on the visible light-driven Z-scheme BiVO4/g-C3N4 heterostructures: Performance, evaluation, and mechanism for dye and antibiotics degradation

Abstract

Herein, the novel and efficient yellow BiVO4/g-C3N4 (BCN) binary composite photocatalyst was successfully fabricated via a simple ultrasonicated-assisted approach for the enhanced photocatalytic removal of methylene blue, tetracycline hydrochloride and ciprofloxacin under simulated visible irradiation. The crystal structure, composition, morphology, textural, optical, and electrochemical properties of the catalysts were comprehensively analyzed. The fishbone-liked BiVO4 were uniformly dispersed on the nano-layered g-C3N4, which not only contributed to the red-shift in the adsorption range but also suppressed the recombination of generated electron-holes. The stable photocurrent of BCN21 with a BiVO4/g-C3N4 mass ratio of 2:1 is higher than that of pristine BiVO4 and g-C3N4. The degradation experiments indicated that the BCN21 exhibited an outstanding photocatalytic removal rate for TC, which was 2.4 and 1.7 times as much as that of the pristine g-C3N4 and BiVO4, respectively. BCN21 also performed an excellent MB discoloration ability (up to 94 % within 180 min). It also showed superior ciprofloxacin degradation rates (3 and 4 times higher than pristine g-C3N4 and BiVO4). Both •O2, •OH, and h+ are involved in the photocatalytic degradation of TC, and that •O2 plays the most crucial role. Moreover, the cyclic experiments proved that the BCN21 possesses good stability after five consecutive runs with no obvious deactivation observed. Overall, this present study provides an insightful strategy for the development of heterojunction photocatalysts towards practical environmental purification.