Photoelectrodeposition of NiMo Catalyst on Cu2O Photocathodes for Enhanced Solar-to-Hydrogen Energy Conversion

초록

Photoelectrochemical (PEC) water splitting offers an eco-friendly method to convert solar energy into hydrogen, with recent advancements improving efficiency. However, despite direct hydrogen production on photocathode surfaces, research into high-performance, stable photocathode-specific catalysts remains limited. In this study, we optimized a NiMo hydrogen evolution reaction (HER) catalyst on Cu2O-based photocathodes using a photoelectrodeposition (PED) method to enhance PEC water-splitting efficiency. Key deposition parameters, including light, current density, applied voltage, and time, were systematically controlled to ensure uniform NiMo catalyst deposition without post-treatments. Under simulated 1-sun illumination, the optimized NiMo catalyst achieved 93% of the performance of conventional Pt catalysts and maintained stable hydrogen production for over 20 hours. Electrochemical analysis confirmed superior PEC performance of the NiMo catalyst, particularly at a fixed current density of −1.5 µA cm-2. This study introduces a noble metal-free catalyst deposition method, advancing solar-to-hydrogen conversion efficiency and long-term PEC device stability.

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