Converting solar energy by photoelectrochemical water splitting has been regarded as a promising way to resolve the global energy crisis and alleviate environmental pollution. Silicon, which is earth-abundant and has a narrow band gap, is an attractive material for photoelectrochemical water splitting. However, Si-based photoelectrodes suffer from photocorrosion, which leads to instability in electrolytes and high overpotential. Herein, we have fabricated a metal–insulator–semiconductor structure of NiO_x/Ni/n-Si photoanodes for highly efficient water splitting. NiO_x/Ni nanoparticles, which act as well-known oxygen evolution catalysts, are deposited on the surface of silicon by facile pulsed electrodeposition. Light absorption and catalytic activity are greatly affected by the coverage of Ni nanoparticles, and the highly efficient NiO_x/Ni catalyst structure is induced by simple annealing. The NiO_x/Ni nanoparticles show highly enhanced charge separation and transport efficiency, which are vital factors for photoelectrochemical water splitting, leading to ∼100% Faradaic efficiency and incident photon-to-current efficiency. A low onset potential of 1.08 V versus a reversible hydrogen electrode for 1 mA/cm² and a high photocurrent density of 14.7 mA/cm² at 1.23 V are obtained.

中文翻译：

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在硅上量身定制的NiO _x / Ni助催化剂，通过脉冲电沉积实现高效的水分解光阳极

通过光电化学水分解转化太阳能被认为是解决全球能源危机和减轻环境污染的一种有前途的方法。硅是地球上富饶的且带隙较窄的硅，是用于光电化学水分解的一种有吸引力的材料。然而，基于硅的光电极遭受光腐蚀，这导致电解质中的不稳定和高过电势。在这里，我们制造了NiO _x / Ni / n-Si光电阳极的金属-绝缘体-半导体结构，用于高效水分解。氧化镍_X通过简便的脉冲电沉积，将作为众所周知的氧气释放催化剂的/ Ni纳米颗粒沉积在硅表面上。Ni纳米粒子的覆盖率极大地影响了光吸收和催化活性，并且通过简单的退火即可诱导出高效的NiO _x / Ni催化剂结构。NiO _x / Ni纳米粒子显示出高度增强的电荷分离和传输效率，这是光电化学水分解的重要因素，从而导致约100％的法拉第效率和入射光子-电流效率。相对于1mA / cm ²的可逆氢电极，其启动电位低，为1.08 V，在1.23 V的条件下，光电流密度为14.7 mA / cm ²，高。