Integrating the active OER and HER components as the heterostructures for the efficient overall water splitting

摘要

AbstractDeveloping the efficient and low-cost electrocatalysts for overall water splitting is of the great importance for the production of H2. The popular bi-functional catalysts usually shown good activity for one half reaction at expense of the activity for another half-reaction, thus given a moderate performance for overall water splitting. In this paper, we have reported on integrating the active OER (Ni3N) and HER (NiMoN) components as Ni3N-NiMoN heterostructures for the effective overall water splitting. The heterostructures were constructed by the controllable nitridation of the Ni-Mo-O precursor anchored on carbon cloth (CC) under NH3atmosphere. The micro-structures of the catalyst could be tuned by regulating the surface properties of CC and the calcination temperature. Under optimized condition, the Ni3N-NiMoN catalysts exhibited good catalytic activity for both OER and HER in alkaline electrolyte. The catalysts can achieve a current density of 10mAcm?2at an overpotential of 31mV for HER, being close to Pt catalyst. Also, it only requiring an overpotential of 277mV to reach current density of 10mAcm?2for OER. Moreover, the cell assembled by the identical Ni3N-NiMoN as both the cathode and anode needs only a cell voltage of 1.54V to achieve current density of 10mAcm?2. The superior performance of Ni3N-NiMoN heterostructures can be ascribed to the following points: 1) the simultaneous presence of active