CoNiOOH nanosheets array enables highly effective value-added chemicals production via nitrite and sulfide electrolysis

[Display omitted] •CoNiOOH nanosheets array is developed as bifunctional catalysts for nitrite and sulfide electrolysis.•The catalyst shows high Faradic efficiency and yield rate towards NH3 synthesis.•It cans also effectively catalyzing the sulfide oxidation reaction with a low potential.•Theoretical analyses reveal that Ni regulates the electronic structure of Co site, and thereby reducing the energy barriers. Here, we show that the CoNiOOH nanosheets array can be applied for catalyzing nitrite reduction and sulfide oxidation reactions (NO2RR and SOR) simultaneously, realizing NH3 production and synchronous desulfuration. As a result, the catalyst achieves a maximal Faradic efficiency of 93 % with the corresponding yield rate of 14.6mg h−1 cm−2 for NH3 production and high robustness over 4 consecutive cycles. Beyond that, it could trigger the SOR with a low potential of 0.65 V vs RHE to reach 100 mA cm−2, far lower than that needed for the water oxidation (1.62 V vs RHE). More importantly, the coupling system composed of NO2RR and SOR could realize value-added products on both sides. Theoretical and experimental analyses validate that Ni regulates the electronic structure of Co site, which optimizes the activation and adsorption of reactants and intermediates, and thus reduce the energy barriers, accounting for the performance enhancement.