A one-step synthesis of Co–P–B/rGO at room temperature with synergistically enhanced electrocatalytic activity in neutral solution

Two-dimensional (2D) nanocomposites are fabricated on reduced graphene oxide (Co–P–B/rGO) via a one-step method at room temperature. By tuning the molar ratio of phosphorus and boron sources in reactants, outstanding bi-functional catalysts for the oxygen evolution reaction (OER) can be obtained with an extremely low onset overpotential of 50 mV and a small Tafel slope of 68 mV dec−1, as well as for the hydrogen evolution reaction (HER) with onset overpotential of 168 mV and a Tafel slope of 82 mV dec−1 in neutral solution (pH = 7.0). The improved performance could be due to the high specific area, efficient electron transfer and the synergistic effects of P and B. We also tested these catalysts in seawater for both OER and HER, which showed favorable activities. This approach to form 2D structures on a reduced graphene oxide may inspire the development of more extraordinary electrochemical catalysts and devices.