2D/2D black-BiOCl/ Fe2O3 heterojunction photo-Fenton catalytic system for enhanced visible-light tetracycline degradation

Though the traditional Fenton reaction is proven to be an efficient advanced oxidation process to cope with contaminants such as tetracycline (TC), constructing a photocatalyst working in synergy with Fenton reaction calls for laborious and ingenious endeavours. In this work, 2D/2D black-BiOCl/Fe2O3 (b-BOC/FO) photo-Fenton catalytic system was constructed via a facile and viable hydro-thermal synthesis process. Every photocatalyst fabricated was later characterized by XRD, FT-IR, SEM, TEM, XPS, UV DRS, and PL analyses. The as-prepared samples' degradation capabilities were assessed under visible light irradiation, b-BOC/FO displayed satisfactory and consistent degrading efficiency over TC under the influence of low concentration of H2O2. Notably, the photo-Fenton catalytic reactivity of sample b-BOC/FO 0.5 was 4.96 and 3.5 times higher than b-BOC and FO, reaching the prime among all composites. This improvement could be attributed to 2D/2D heterojunction structure, oxygen vacancies acting as electron mediators and the synergy between photocatalysis and Fenton reaction. Moreover, a rational photo-Fenton catalytic mechanism was proposed after active species trapping experiments, which could bring new insight into photocatalytic system for water contaminant treatment.