“Blooming on rods” design 3D heterostructure toward boost electrocatalytic oxygen evolution reaction

Developing boosting as well as stable catalysts toward the oxygen evolution reaction (OER) is crucial for environmentally friendly hydrogen evolution via water decomposition. Herein, we report 3D CoMoO 4 /Ni 3 S 2 heterostructure constructed by sequential hydrothermal strategy to synergistically enhance OER capability and kinetics. In 1 M KOH, the CoMoNiS@NF exhibits efficient alkaline OER capability with ultralow overpotentials of 152 mV to achieve 100 mA cm −2 , surpassing CoMo@NF (384 mV), commercial RuO 2 @NF (500 mV), and NF (590 mV), with a Tafel slope of 46.5 mV dec −1 . In addition, it also demonstrates efficient OER capability with overpotentials of 445 mV and 1.3 V to achieve 100 and 20 mA cm −2 in 0.5 M H 2 SO 4 and 0.01 M PBS, respectively. From DFT calculations, it is noticed that this heterojunction accelerates charge transfer by forming a Schottky barrier through the close interface coupling between CoMoO 4 nanorods and Ni 3 S 2 nanosheets, thereby enhancing performance. Besides, regardless of the medium, the LSV curves do not change significantly after 300 CV cycles, further indicating the stable existence of the heterostructure interface during the catalytic process. This work provides a robust strategy for engineering heterostructured OER catalysts via interfacial electronic control.