P–Nb₄C₃T_x Nanosheets Fabricated by a Low-Temperature Phosphating Process as Electrocatalysts for Electrochemical Water Splitting

Electrochemical water splitting technology is a green, clean, and pollution-free energy technology that can produce hydrogen (H 2 ) and oxygen (O 2 ), which is of great significance for alleviating the world energy questions and improving the surrounding environment. Therefore, it is important to develop and prepare low-cost, high-activity, and stable electrocatalysts to improve water splitting technology. In this study, the P-doped bifunctional catalyst (P–Nb 4 C 3 T x ) was prepared by introducing the P element into a few layers of Nb 4 C 3 T x by low-temperature phosphating. The low-temperature phosphating can enhance the HER and OER behaviors and achieve optimal overall water splitting ability. It needs only an overpotential of 92 mV to achieve 10 mA·cm –2 for HER and only 278 mV for OER in 1.0 M KOH solution. When P–Nb 4 C 3 T x served as the anode and cathode to construct a water electrolysis cell, a small cell voltage of 1.572 V is needed at 10 mA·cm –2 in 1.0 M KOH. This research is viable for the overall water splitting.