Enhanced effect of Ce addition and visible light irradiation on one-step hydrothermally synthesized Ce2S3/Ni3S2 heterostructured electrocatalyst for efficient overall water splitting

In this study, the electroactive Ni 3 S 2 /Ce 2 S 3 heterostructure (denoted as Ce–Ni(OH) 2 –S) was achieved by a facile one-step hydrothermal approach through the incorporation of Ce and sulfur into Ni(OH) 2 . The effect of Ni 3 S 2 /Ce 2 S 3 heterostructure on electrocatalytic water splitting is investigated in detail in 1.0 M KOH. The as-prepared Ce–Ni(OH) 2 –S exhibits long-term stability and excellent catalytic activity at a current density of 100 mA cm −2 with overpotentials of 327 mV and 356 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. Serving as bifunctional catalysts, the Ce–Ni(OH) 2 –S electrode merely requires a 1.519 V cell voltage to reach 10 mA cm −2 . The synergistic effect of the metal sulfide heterojunction (composed of Ce and Ni) effectively facilitates reactant transfer and electron migration, thereby significantly enhancing the electrocatalytic activity. Furthermore, the catalytic performance is further enhanced with the overpotentials of 312 and 284 mV for OER and HER, respectively, by applying visible light irradiation. This work offers a new strategy for improving the electrocatalytic performance of water splitting under visible light irradiation condition.