Compositional and electronic reconstruction to co-incorporated NiOSO4–NiMoO4 for boosting electrocatalytic overall water splitting/overall urea splitting reactions

Abstract

Herein, we grew in situ Co-incorporated NiOSO4–NiMoO4 heterostructures on nickel foam (Co-NiSMoO/NF). The introduction of S2− and MoO42− into CoNi-ZIF precursor leads to the compositional and electronic reconstruction, resulting in the Co-NiSMoO/NF nanostructures. The attractive features in the morphology, composition, and electronic structure cooperatively endow them with high electrocatalytic performances. As a result, the Co-NiSMoO/NF nanostructures exhibit superior electrocatalytic performances to oxygen evolution, urea oxidation, and thus overall water/urea splitting reactions (OER/UOR/OWS/OUS). Specifically, the Co-NiSMoO/NF shows a high electrocatalytic OER activity, with low overpotentials of 172 mV@10 mA cm−2, 238 mV@20 mA cm−2, 278 mV@50 mA cm−2, 308 mV@100 mA cm−2 in alkaline. For UOR, the overpotential is just as low as 1.318 V@10 mA cm−2, 1.330 V@20 mA cm−2, 1.346 V@50 mA cm−2, and 1.401 V@100 mA cm−2. Especially, the voltage of the record cell even drops to 1.446 V@10 mA cm−2 to OUS. Furthermore, the Co-NiSMoO/NF electrocatalysts still stable to OER, UOR, and OUS even for up to 100 h. More importantly, we also realized H2 production in a green manner driven by solar. Under solar illumination on a solar panel, H2 production speed is even as high as 408 L h−1 m−2.