Structural modulation on NiCo2S4 nanoarray by N doping to enhance 2e-ORR selectivity for photothermal AOPs and Zn-O2 battery

As a H2 O2 generator, a 2e- oxygen reduction reaction active electrocatalyst plays an important role in the advanced oxidation process to degrade organic pollutants in sewage. To enhance the tendency of NiCo2 S4 towards the 2e- reduction reaction, N atoms are doped in its structure and replace S2- . The result implies that this weakens the interaction between NiCo2 S4 and OOH*, suppresses O-O bond breaking and enhances H2 O2 selectivity. This electrocatalyst also shows photothermal effect. Under photothermal heating, H2 O2 produced by the oxidation reduction reaction can decompose and releaseOH, which degrades organic pollutants through the advanced oxidation process. Photothermal effect induced by the advance oxidation process shows obvious advantages over the traditional Fenton reaction, such as wide pH adaptation scope and low secondary pollutant due to its Fe2+ free character. With Zn as anode and the electrocatalyst as cathode material, a Zn-O2 battery is assembled. It achieves electricity generation and photothermal effect induced by the advance oxidation process simultaneously.