MoP4/Ni3S2/MoO3 heterogeneous structure nanorod arrays for efficient solar-enhanced overall water splitting

NiMo-based materials are promising candidates for alkaline overall water splitting. Unfortunately, the catalytic activity of most nickel-molybdenum based electrocatalysts is still far below the standard for practical applications. Therefore, the development of new nickel-molybdenum-based multi-component catalysts is expected to achieve complementary advantages and improve electrocatalytic water splitting activity. Herein, we have synthesized a multi-phase heterostructured electrocatalyst grown on NiMoO4 nanorods using the strategy of simultaneous phosphatization and sulfidation. The interface formed between multi-phase heterostructures plays a crucial role in solar-enhanced overall water splitting. According to the experimental results, at a current density of 10 mA cm(-2), the required overpotentials of MoP4/Ni3S2/MoO3/alpha-NiMoO4/beta-NiMoO4 (NiMo-PS@NF) catalysts for the HER and OER are as low as 35 mV and 211.8 mV, respectively. The overall water splitting cell voltage is as low as 1.391 V (10 mA cm(-2)) due to the high intrinsic activity and efficient electron transfer efficiency. Meanwhile, the bifunctional electrocatalyst can operate continuously for at least 65 hours at 100 mA cm(-2) current density. Notably, this electrocatalyst exhibits enhanced electrocatalytic water splitting activity under simulated sunlight irradiation. Surprisingly, the electrocatalyst exhibits a solar-to-hydrogen efficiency of 19.42% in a photoelectric coupled water splitting system. In addition, the density functional theory (DFT) results are in agreement with the experimental results. This work provides a new idea for improving electrocatalytic activity by rational use of solar energy.

Automated summary

Researchers have synthesized a multi-phase heterostructured electrocatalyst for solar-enhanced overall water splitting. The catalyst exhibits high activity and efficiency, enabling efficient water electrolysis at low overpotentials. It also shows enhanced activity under simulated sunlight irradiation.