Enabling Si photoanodes for efficient solar water oxidation would facilitate the development of solar fuel conversion, but it is challenging owing to Si surface passivation via photo-induced corrosion in aqueous electrolytes. To overcome this challenge, most approaches have focused on improving the stability of Si by coating dense and thin protective layers using high vacuum-based techniques such as atomic layer deposition. However, these procedures are costly, making scalability for practical applications difficult. Herein, we report a modified electroless deposition (ELD) method to uniformly deposit protective and catalytic Ni films on Si wafers, resulting in efficient and stable Si photoanodes for solar water oxidation. The optimized Ni/n-Si photoanode achieves an onset potential of ∼ 1.09 V vs. a reversible hydrogen electrode and a saturation current density of ∼ 27.5 mA/cm² under AM 1.5 G illumination at pH 14. The ELD method is additionally capable of Ni deposition on a 4-inch n-Si wafer, demonstrating the first 4-inch Si photoanode. The solar water oxidation of the ELD-Ni/n-Si photoanode can be further improved by surface texturing, built-in n–p junctions, or coupling with more efficient catalysts.

中文翻译：

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启用硅光电阳极，以通过化学沉积的镍有效地分解太阳能

使Si光电阳极有效进行太阳能水氧化将促进太阳能燃料转化的发展，但是由于通过在水性电解质中进行光致腐蚀而使Si表面钝化，因此具有挑战性。为了克服这一挑战，大多数方法都集中在通过使用基于高真空的技术（例如原子层沉积）涂覆致密且薄的保护层来提高Si的稳定性。但是，这些过程成本高昂，因此很难为实际应用提供可伸缩性。本文中，我们报告了一种改良的化学沉积（ELD）方法，该方法可在Si晶片上均匀沉积保护性Ni膜和催化Ni膜，从而为太阳能水氧化提供了有效而稳定的Si光阳极。经过优化的Ni / n-Si光电阳极可实现约1.09 V vs.²在pH为14的AM 1.5 G光照下。ELD方法还能够在4英寸n-Si晶片上沉积镍，这证明了第一个4英寸Si光电阳极。ELD-Ni / n-Si光电阳极的太阳能氧化可以通过表面纹理化，内置的n-p结或与更有效的催化剂耦合来进一步改善。