Nickel-coated silicon photocathode for water splitting in alkaline electrolytes  

作　　者：Ju Feng Ming Gong Michael J. Kenney Justin Z. Wu Bo Zhang Yanguang Li Hongjie Dai 

机构地区：[1]Department of Chemistry, Stanford University, Stanford, California 94305, USA [2]Institute of Functional Nano & Soft Materials, Soochow University, Suzhou 215123, China

出　　处：《Nano Research》2015年第5期1577-1583,共7页纳米研究（英文版）

摘　　要：Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matching the solar spectrum [2]. Here we investigate employing nickel both as a catalyst and protecting layer of a p-type silicon photocathode for photoelectrochemical hydrogen evolution in basic electrolytes for the first time. The silicon photocathode was made by depositing 15 nm Ti on a p-type silicon wafer followed by 5 nm Ni. The photocathode afforded an onset potential of -0.3 V vs. the reversible hydrogen electrode （RHE） in alkaline solution （1 M KOH）. The stability of the Ni/Ti/p-Si photocathode showed a 100 mV decay over 12 h in KOH, but the stability was significantly improved when the photocathode was operated in potassium borate buffer solution （pH ≈ 9.5）. The electrode surface was found to remain intact after 12 h of continuous operation at a constant current density of 10 mA/cm^2 in potassium borate buffer, suggesting that Ni affords good protection of Si based photocathodes in borate buffers.切开的 Photoelectrochemical (PEC ) 水是一条有希望的途径收获并且存储太阳能[1 ] 。硅广泛地由于它匹配太阳的光谱的合适的乐队差距(1.12 eV ) 为 PEC photoelectrodes 被调查了[2 ] 。这里，我们调查作为催化剂两个都采用镍并且第一次在基本电解质为 photoelectrochemical 氢进化保护 p 类型硅光阴极的层。硅光阴极被在 5 nm Ni 跟随的 p 类型硅晶片上扔 15 nm Ti 做。光阴极在碱的答案(1 M KOH ) 负担得起 0.3 V 对可逆的氢电极(RHE ) 的一个发作潜力。Ni/Ti/p-Si 光阴极的稳定性在 KOH 在 12 h 上看了 100 mV 腐烂，但是稳定性显著地被改进光阴极什么时候在钾硼酸盐缓冲区答案被操作(pH 9.5 ) 。电极表面被发现在 10 妈 / 厘米的经常的当前的密度在连续操作的 12 h 以后仍然保持未经触动 < 啜 class= “ a-plus-plus ” > 在钾硼酸盐缓冲区的 2 </sup> ，建议 Ni 负担得起 Si 的好保护在硼酸盐缓冲区基于光阴极。

关 键 词：photoelectrochemical water splitting silicon photocathode NICKEL 

分 类 号：TQ153.12[化学工程—电化学工业] TM914.4[电气工程—电力电子与电力传动]