Inducing a deep impurity level in Li_2SnO_3 by ionic Bi-O bonding to enhance light absorption in photocatalysis

摘要

Orbital engineering is an important strategy for modulating light absorption in photocatalysis. Here, Bi doping of the oxide photocatalyst Li2SnO3 to enhance light absorption was rationally designed by orbital engineering. Based on density functional theory, owing to the lower Bi 6s energy level compared with that of Sn 5s, a deep impurity energy level induced by ionic Bi-O bonds is generated in the middle band gap of Li2SnO3. The impurity energy level can facilitate the utilization efficiency of light absorption, leading to remarkably enhanced photocatalytic performance. For Li2Sn0.9Bi0.1O3, the photodegradation rate of tetracycline solution reached 76% within 30 min, which was approximately 2.6 times higher than that for Li2SnO3. A radical trapping experiment revealed that the holes (h thorn ) play a dominant role in the elimination reaction. Finally, liquid chromatography-mass spectrometry was performed to monitor the photocatalytic process. This study lays a foundation for rational design of photocatalysts with excellent light absorption for photocatalysis. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.