Enhanced photocatalytic activity of novel α-Bi2O3@g-C3N4 composites for the degradation of endocrine-disrupting benzophenone-3 in water under visible light

• Published in: Sustainable environment research Vol. 32; no. 1; pp. 1 - 19
• Main Authors: Berekute, Abiyu Kerebo, Yu, Kuo-Pin, Chuang, Yi-Hsueh Brad
• Format: Journal Article
• Language: English
• Published: BMC 14.03.2022
• Subjects: Photocatalytic degradation; Ultraviolet filter; Z-scheme heterojunction; α-Bi2O3@g-C3N4
• ISSN: 2468-2039; 2468-2039
• DOI: 10.1186/s42834-022-00129-8

Abstract The commonly used benzophenone-3 (BP-3) as ultraviolet filter ingredients is an endocrine-disrupting chemical that has received particular attention owing to its environmental ubiquity, and it poses a threat to aquatic biota and human health. In this study, novel α-Bi 2 O 3 @g-C 3 N 4 nanocomposites with different α-Bi 2 O 3 contents and enhanced photocatalytic activity were synthesized by a mixing calcination method. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, N 2 adsorption/desorption isotherm analysis, electrochemical impedance spectroscopy, photoluminescence spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. The 1 wt% α-Bi 2 O 3 @g-C 3 N 4 composite exhibited the highest rate constant of 0.42 h -1 for photocatalytic degradation of BP-3, which was up to 6.3 times higher than that of g-C 3 N 4 (0.07 h -1 ). The enhanced photocatalytic activity might be due to the enhanced separation of photogenerated electron-hole (e - -h + ) charge pairs and suppression of e - -h + recombination. Scavenging experiments suggested that •OH, h +  and •O 2- worked together in the α-Bi 2 O 3 @g-C 3 N 4 photocatalytic process. The EPR spectra demonstrated that the α-Bi 2 O 3 @g-C 3 N 4 composites generated considerably more •O 2- and •OH than g-C 3 N 4 . Finally, cyclic degradation experiments showed the reusability of 1 wt% α-Bi 2 O 3 @g-C 3 N 4 for BP-3 removal.