Modulation of morphology and electronic structure of nickel thiophenedicarboxylic framework microrod arrays with NiS for efficient water oxidation.

Metal-organic frameworks (MOFs) have been a hot topic as oxygen evolution reaction (OER) electrocatalysis owing to their superior specific surface area, plentiful metal active sites and modifiable morphology and composition. Nonetheless, the low electronic conductivity, restricted active sites and lack of structural robustness in MOFs impede their efficacy as catalysts in water electrolysis processes. Herein, nickel thiophenedicarboxylic framework@NiS (Ni-TDC@NiS) composites were prepared on a nickel foam substrate via a two-step hydrothermal method. The results indicate that NiS not only regulates the morphology and local electronic structure of Ni-TDC, but also enhances the structural stability, which leads to the superior OER performance with an overpotential of 220 mV at 10 mA cm, and the Tafel slop of 50.76 mV dec. Furthermore, the assembled overall water electrolysis device with Ni-TDC@NiS and RuNi-TDC as anode and cathode electrodes requires the voltage of only 1.50 V at a current density 10 mA cm, and it can run stably for more than 70 h. This study provides a new idea for enhancing the electronic conductivity of MOF-based electrocatalysts for efficient water oxidation.