Rational construction of non-noble metal-based electrocatalysts for energy generation and environmental electrooxidation receives attention because of their simplicity, versatility, and high efficiency. In this study, a novel core–shell electroactive material architecture is developed by electrodepositing cobalt sulfide shell over core NiCo₂O₄ structure on Ni-Foam substrate, which is developed by hydrothermal process. The synergistic effect of the three-dimensional chrysanthemum-like NiCo₂O₄ with CoS shell exhibits superior activity towards oxygen evolution reaction with high durability and lower onset potential obtained at 1.52 V vs. RHE (overpotential 290 mV @ 10 mA/cm²) in alkaline solution. The electron pairs from NiCo₂O₄ and CoS along with increased active sites from their interfacial interaction considerably improve the charge transfer phenomena. The electrocatalytic activity in the presence of urea is also investigated, which aids in reducing the onset potential to 118.4 mV vs. RHE. A considerably higher current density of 78 mA/cm² is achieved at the potential of 0.5 V, which is comparatively higher than that of other electrocatalysts. Thus, the activity from sulfide/oxide core–shell architectures proves to have a high potential in efficient electrochemical reactivity producing green energy.

用于能量产生和环境电氧化的非贵金属基电催化剂的合理构造因其简单性，多功能性和高效率而备受关注。在这项研究中，通过将硫化钴壳电沉积在Ni-Foam基板上的NiCo ₂ O ₄核心结构上，开发了一种新颖的核-壳电活性材料结构，该结构是通过水热工艺开发的。具有CoS壳的三维菊花状NiCo ₂ O ₄的协同作用显示出对氧气析出反应的优异活性，具有较高的耐久性，并且在1.52 V的条件下相对于RHE具有较低的起始电位（在10 mA / cm ^2时超电位290 mV）在碱性溶液中。来自NiCo ₂ O ₄和CoS的电子对以及来自它们的界面相互作用的增加的活性位点大大改善了电荷转移现象。还研究了在尿素存在下的电催化活性，这有助于将起始电位降低至相对于RHE的118.4 mV。在0.5 V的电势下可实现更高的78 mA / cm ^2的电流密度，该电流密度比其他电催化剂要高。因此，硫化物/氧化物核-壳结构的活性被证明在产生绿色能源的有效电化学反应中具有很高的潜力。