Regulating Crystal Facets of MnO2 for Enhancing Peroxymonosulfate Activation to Degrade Pollutants: Performance and Mechanism

On the catalyst surface, crystal facets with different surface atom arrangements and diverse physicochemical properties lead to distinct catalytic activity. Acquiring a highly reactive facet through regulation is an efficient strategy promote oxidative decomposition of wastewater organic pollutants via peroxymonosulfate (PMS) activation. However, mechanism which affect PMS activation still unclear. In this study, three facet-engineered ?-MnO2 exposed were prepared facile hydrothermal route. The 310-MnO2 exhibited superior performance 100-MnO2 110-MnO2. Moreover, 310-MnO2/PMS system was active over wide pH range resistant interfering substances from wastewater. These advantages make it promising for practical treatment. Based on quenching experiments, electron paramagnetic resonance (EPR) analysis, solvent exchange, electrochemical measurements, mediated transfer found be dominant nonradical pathway p-chloroaniline (PCA) degradation. A sulfhydryl group (-SH) masking experiment showed that Mn atoms sites addition, density functional theory (DFT) calculations confirmed {310} promoted adsorption/activation PMS, favored formation more metastable complexes surface. reaction obtained here clarifies relationship between facets. This study provides significant insights into rational design high-performance catalysts water remediation.