BiPO 4 /Ov-BiOBr High-Low Junctions for Efficient Visible Light Photocatalytic Performance for Tetracycline Degradation and H 2 O 2 Production.

Tang, Minghui; Li, Xibao; Deng, Fang; Han, Lu; Xie, Yu; Huang, Juntong; Chen, Zhi; Feng, Zhijun; Zhou, Yingtang

Through a two-step solvothermal method, different molar ratios of BiPO4 were grown in situ on the surface of oxygen-vacancy-rich BiOBr (Ov-BiOBr), successfully constructing a BiPO4/Ov-BiOBr heterojunction composite material. By constructing a novel type I high-low junction between the semiconductor BiPO4 and Ov-BiOBr, stronger oxidative holes or reductive electrons were retained, thereby improving the redox performance of the photocatalyst. The composite catalyst with a 10% molar content of BiPO4 demonstrated the highest degradation rate of tetracycline (TC), degrading over 95% within 90 min, with a rate constant of 0.02534 min−1, which is 2.3 times that of Ov-BiOBr and 22 times that of BiPO4. The 10% BiPO4/Ov-BiOBr sample displayed the best photocatalytic activity, producing 139 μmol·L−1 H2O2 in 120 min, which is 3.6 times the efficiency of Ov-BiOBr and 19 times that of BiPO4. This was due to the appropriate bandgap matching between BiPO4 and Ov-BiOBr, the photo-generated electron transfer channel via Bi-bridge, and efficient charge separation. It was inferred that the free radical species ·OH and ·O2− played the dominant role in the photocatalytic process. Based on experimental and theoretical results, a possible photocatalytic mechanism was proposed.

VISIBLE spectra; TETRACYCLINES; TETRACYCLINE; PHOTOCATALYSTS; CHARGE exchange; SEMICONDUCTOR junctions

Catalysts (2073-4344), 2023, Vol 13, Issue 3, p634

2073-4344

Academic Journal

10.3390/catal13030634