Pauling-type adsorption of O ₂ induced electrocatalytic singlet oxygen production on N–CuO for organic pollutants degradation

Abstract

Due to environmentally friendly operation and on-site productivity, electrocatalytic singlet oxygen ( ¹O ₂) production via O ₂ gas is of immense interest in environment purification. However, the side-on configuration of O ₂ on the catalysts surface will lead to the formation of H ₂O, which seriously limits the selectivity and activity of ¹O ₂ production. Herein, we show a robust N-doped CuO (N–CuO) with Pauling-type (end-on) adsorption of O ₂ at the N–Cu–O ₃ sites for the selective generation of ¹O ₂ under direct-current electric field. We propose that Pauling-type configuration of O ₂ not only lowers the overall activation energy barrier, but also alters the reaction pathway to form ¹O ₂ instead of H ₂O, which is the key feature determining selectivity for the dissociation of Cu–O bonds rather than the O–O bonds. The proposed N dopant strategy is applicable to a series of transition metal oxides, providing a universal electrocatalysts design scheme for existing high-performance electrocatalytic ¹O ₂ production.

Abstract

Side-on configuration of O ₂ on the catalysts conventionally leads to reduction of O ₂ to water. Here, the authors propose a nitrogen doping strategy with Pauling-type adsorption of O ₂ for selective electrocatalytic singlet oxygen production.