Efficient Co@CoPx core-shell nanochains catalyst for the oxygen evolution reaction

Co@CoPx core-shell nanochains were prepared via a direct-current arc-discharge method and subsequent phosphorization at 350 degrees C. The nanochains comprise nanospheres connected to each other with a length of several micrometers. The amount of CoPx can be easily changed by varying the phosphorization time. In the Co@CoPx core-shell structure, Co serves as a conductive channel, which improves the reaction kinetics of the oxygen evolution process on CoPx. Co metal can also inject electrons into CoPx, thus changing the work function of CoPx and improving its oxygen evolution efficiency. Based on the optimized structure, the Co@CoPx nanochains catalyst exhibits excellent oxygen evolution performance. Co@CoPx achieves an overpotential of 310 mV at a current density of 10 mA cm(-2), which is lower than that of CoPx (418 mV), Co (408 mV), and RuO2 (317 mV). Furthermore, Co@CoPx exhibits good durability during the long-term electrochemical test.