Pauling-type adsorption of O2 induced electrocatalytic singlet oxygen production on N–CuO for organic pollutants degradation

Due to environmentally friendly operation and on-site productivity, electrocatalytic singlet oxygen (1O2) production via O2 gas is of immense interest in environment purification. However, the side-on configuration of O2 on the catalysts surface will lead to the formation of H2O, which seriously limits the selectivity and activity of 1O2 production. Herein, we show a robust N-doped CuO (N-CuO) with Pauling-type (end-on) adsorption of O2 at the N-Cu-O3 sites for the selective generation of 1O2 under direct-current electric field. We propose that Pauling-type configuration of O2 not only lowers the overall activation energy barrier, but also alters the reaction pathway to form 1O2 instead of H2O, 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 1O2 production.