Enhanced visible-light-driven photocatalytic activity of Bi12O15Cl6/B12WO6 Z-scheme heterojunction photocatalysts for tetracycline degradation

Bismuth oxychloride (Bi12O15C16), as a new bismuth compound photocatalyst, emerges excellent visible-light photocatalytic activity. Herein, a novel Z-scheme heterojunction photocatalyst of Bi12O15C16/Bi2WO6 (BOC/BWO) was firstly synthesized via a facile solvothermal-calcining method. The crystal structure, morphology, energy band and photocatalytic performance of the as-prepared samples were investigated by multiple physicochemical techniques. The BOC/BWO sample with a molar ratio of 2:1 exhibited the highest TC degradation rate in comparison with that of all samples, which could reach 81.2% within 1 h under the visible-light irradiation. The reactive species trapping experiments and electron spin resonance results indicated that the superoxide radicals and photogenerated holes are the major active species in the photodegradation of TC. According to the photocurrent measurements, electrochemical impedance spectra and photoluminescence spectra, the greatly enhanced photocatalytic activity of BOC/BWO Z-scheme heterojunction could be attributed to high separation efficiency of photogenerated electron-hole pairs.