Selective photocatalytic remediation of para-substituted phenol pollutants over iodine-doped Bi2MoO6 via in-situ generated H2O2 and iodine radicals activation

Abstract

The preferential degradation of specific harmful organic pollutants in photocatalytic processes is critically important, yet remains a significant challenge due to the uncontrolled nature of reactive species, particularly those with high oxidation potentials such as •OH and h+. In this work, we designed an iodine-doped Bi2MoO6 semiconductor to establish a system for photo-induced H2O2 generation. The incorporation of iodine led to a steady enhancement in the selective photo-degradation of para-substituted phenolic pollutants, known precursors to carcinogenic p-benzoquinones, facilitated by the activation of iodine radicals through H2O2. This system exhibited impressive photo-degradation (96 %) and mineralization efficiency for acetaminophen (APAP), along with superior environmental applicability. It also demonstrated selectivity in degrading phenols with para-substitutions. The in-situ generation and activation of H2O2 and •I were identified as the crucial pathways in this photocatalytic system. This work provides a novel modification path to accomplish the simultaneous generation and utilization of H2O2 in the photocatalytic system and ultimately makes a remarkable performance for the targeted remediation of environmental pollutants.