Exploring the activation pathway of photo-induced electrons in facets-dependent I− doped BiOCl nanosheets for PCPNa degradation

Abstract

Electrons can degrade pentachlorphenate sodium (PCPNa) directly or activate molecular oxygen to produce and ·OH for its degradation. However, less work has been performed to control such two kinds of reaction pathway by modifying BiOCl. Herein, we firstly regulated the reaction pathway between electrons and PCPNa by adjusting the amount of surface oxygen vacancies (OVs) and surface adsorbed hydroxyl groups in I− doped BiOCl exposed with different facets. OVs on (001) facets-exposed I− doped BiOCl enabled large amount of PCPNa to adsorb on its surface and facilitated the direct reaction between electrons and PCPNa. In contrary, more surface adsorbed hydroxyl groups and oxygen on (010) facets-exposed I− doped BiOCl can retard the direct reaction between electrons and PCPNa via lowering the adsorption of PCPNa and increasing the activation of molecular oxygen by electrons. Although more and ·OH generated in I− doped (010)-facets exposed BiOCl, I− doped (001)-facets exposed BiOCl exhibited better photocatalytic activity. We proposed that the direct reaction between electrons and PCPNa can enhance the utilization efficiency of photogenerated electrons and improve photocatalytic degradation efficiency of PCPNa.