Improved peracetic acid activation under simulated solar-light irradiation by regulating shells of Cu2O: In-situ photothermal activation

Abstract

Advanced oxidation processes based on light-mediated peracetic acid (PAA) activation are novel degradation systems for wastewater purification. In this work, different shells of Cu2O are controllably synthesized and used to activate PAA under simulative solar light. Interestingly, the kobs in the system without temperature control is 2.47 times that in the temperature-controlled system, implying the important role of the photothermal conversion effect in PAA activation. Reactive oxygen species identification demonstrates that photothermal promotes the decomposition of PAA into radical OH with higher redox potential instead of R–O, which together with non-radical 1O2 achieves a high mineralization rate (72.49%). The core–shell structure enhances light absorption and photogenerated charge separation of Cu2O, thereby improving photothermal conversion efficiency. Meantime, the in-situ photothermal conversion effect expedites the diffusion of ROS and the cycle of active Cu(Ⅱ)/Cu(Ⅰ) ultimately achieves the high-efficiency and long-lasting PAA activation. This work provides novel strategies for solar energy utilization and PAA activation processes in wastewater purification.