Surface oxygen vacancies modified Bi2MoO6 double-layer spheres: Enhanced visible LED light photocatalytic activity for ciprofloxacin degradation

Oxygen vacancies can regulate the energy band structure of semiconductor photocatalytic materials, and serve as electron traps and active sites to improve the photocatalytic activity of the photocatalyst. Herein, we prepared Bi2MoO6 flower spheres with a double-layer structure by a simple solvothermal method, and achieved the controllable introduction of oxygen vacancies through subsequent air calcination at different temperatures. The double-layer structure of Bi2MoO6 improved the light absorption because of multiple reflections. Compared with the pristine Bi2MoO6, the introduction of oxygen vacancies regulated the energy band structure of Bi2MoO6, improved the separation and transfer rate of electron-hole pairs, and produced more active species such as h(+) and O-1(2). Among all samples prepared, BMO-350 had the best activity, which could degrade 90.6% of ciprofloxacin (10 mg/L) within 80 min under the irradiation of 6000 K visible LED light. While under ultraviolet, 3000 K, 4500 K, 6000 K visible, red Led light and xenon lamp irradiation, the CIP degradation efficiency reached 94.9%, 73.77%, 85.9%, 89%, 16.24%, and 94.7%, respectively, demonstrated that the appreciable photocatalytic activity under the low energy light source. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Oxygen vacancies can enhance the photocatalytic activity by regulating the energy band structure and improving electron transfer rate of semiconductor photocatalytic materials. The double-layer structure of Bi2MoO6 shows improved light absorption capabilities. Among the samples prepared, BMO-350 exhibited the best photocatalytic activity, degrading ciprofloxacin efficiently under various light sources.