Stress modulation on photodegradation of tetracycline by Sn-doped BiOBr

Abstract

Stress modulation is an effective method to improve the performance of photocatalysts. In this paper, the stress modulated photocatalytic performance was achieved by constructing lateral pseudo-heterogeneous interface of Sn(IV)-doped BiOBr nanosheets, which were synthesized by a simple one-pot hydrothermal method. The stress value was calculated by W-H plot method based on the XRD results. The modulated photocatalytic performance was demonstrated by the photocatalytic degradation of tetracycline (TC) under visible light irradiation. The presence of tensile stress makes that 16% Sn(IV)-doped BiOBr has the strongest photo-generated current, and exhibits a p-n type electrochemical performance from the M-S plots, which results in the best photocatalytic degradation ability of ~ 16% Sn(IV)-doped BiOBr. Pure BiOBr is a n type semiconductor, Sn(IV)-doping makes BiOBr to be a p-n type semiconductor. It is found that the internal stress changes from compress force to stretch force with the increase of Sn(IV) content from 1% to 20%. Different radical sacrificial agents were added to clarify the photocatalytic mechanism. The relationship between internal stress and the photocatalytic performance has great potential to design new photocatalysts for the treatment of environmental pollutants.