Integrating the plasmonic effect and p-n heterojunction into a novel Ag/Ag2O/PbBiO2Br photocatalyst: Broadened light absorption and accelerated charge separation co-mediated highly efficient…

By Hai Guo, C. Niu, Dawei Huang, Ning Tang, Chao Liang, Lei Zhang, Xiaoju Wen, Yang Yang, Wenjun Wang, Guangming Zeng. Chemical Engineering Journal, 2019

187 citations recorded by the source corpus.

Abstract Among several factors that influence the effectiveness of a semiconductor mediated photocatalysis, efficient charge separation and broadened light absorption are regarded as two of the most important parameters. Herein, a series of plasmonic p-n heterojunction Ag/Ag2O/PbBiO2Br photocatalysts with wide spectrum responses were successfully fabricated through a facile precipitation-calcination method. The obtained samples display exceptional photocatalytic performance for the degradation of tetracycline (TC), and the results reveal that the 10 wt% Ag/Ag2O/PbBiO2Br exhibits the optimal activity, which can efficiently decompose 84.4% of TC after 90 min of visible light irradiation. While under NIR light irradiation, the TC removal ratio can still reach 50.9% with 240 min. Besides, no significant deterioration in the degradation performance is observed even after four cycling runs. The photoactivity enhancement of Ag/Ag2O/PbBiO2Br can be credited to the synergistic effect between the local surface plasmon resonance (LSPR) effect of metallic Ag and the p-n heterojunction of Ag2O/PbBiO2Br, which not only greatly broadens the light utilization, but also remarkably accelerates the charge separation. The radical trapping experiments and the ESR measurements ascertains that O2−, h+ and OH play a critical role in the degradation of TC under visible light irradiation, while O2− and h+ become the major reactive species in NIR light-driven reaction. According to the experimental results, the plausible reaction mechanisms for TC degradation over Ag/Ag2O/PbBiO2Br composite are proposed under both visible and NIR light irradiation. This work provides some guidance for rational construction of novel plasmonic p-n heterojunction photocatalysts to meet ever-increasing environmental requirements.

Subfields: Electrical and Electronic Engineering, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/df12a3b9aa6e170cc7b48682e39d23f63eba935e