Ultrafast Hot Ion-exchange Triggered Electrocatalyst Modification and Interface Engineering on Silicon photoanodes

Publication date: Available online 20 January 2020Source: Nano EnergyAuthor(s): Qian Cai, Wenting Hong, Chuanyong Jian, Wei LiuABSTRACTSlow charge transfer kinetics and poor stability are two critical issues for silicon (Si) photoanodes in photoelectrochemical (PEC) water splitting. Herein, a facile and ultrafast interfacial reaction was performed on n-Si/Ni for stable and high-performance Si photoanode by regulating both the Ni electrocatalyst and Si surface. The calculated and experimental results reveal that highly catalytic oxygen vacancies-rich Fe:NiOOH layer will be formed on Ni surface during the hot Fe ions exchange reaction, which can create abundant active sites for oxygen evolution reaction (OER). The interfacial reaction also can modulate the interfacial state of Si photoanode to increase barrier height for n-Si/Ni/Fe:NiOOH photoanode, thereby accelerating the charge separation and transportation. More significantly, a thin iron silicide (FeSi2) layer will be generated on Si surface (Ni-free region), which is beneficial for the stability of Si photoanode. This work provides a low-cost and straightforward approach to design high-performance Si photoanodes by interface engineering and electrocatalyst defects regulation.Graphical abstract
Source: Nano Energy - Category: Nanotechnology Source Type: research
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