(Invited) Si/NiCoSe x Nanorods Photocathode for Enhanced Photoelectrochemical Hydrogen Production

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2016-02; no. 34; p. 2233
• Main Authors: Zhang, Xingwang, Zhang, Hongxiu, He, Denghong
• Format: Journal Article
• Language: English
• Published: 01.09.2016
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2016-02/34/2233

Hydrogen is considered as the ideally sustainable alternative to fossil fuels. Photoelectrochemical (PEC) water splitting is attractive as it can store solar energy in the form of hydrogen. Silicon as an earth-abundant and efficient visible light absorption material has been widely used in PEC for hydrogen generation. However, achieving a high photocurrent density still faces a challenge when utilizing silicon as a photocathode owing to its sluggish hydrogen evolution reaction (HER) kinetics and low light harvesting capability. Here, we design a novel one-dimensional photocathodes - Si/NiCoSe x nanorods using a facile photo-assistant electrodeposition method and demonstrate their enhanced PEC hydrogen production performance with high photocurrent density. Si nanorods were covered with NiCoSe x electrocatalysts, where electrons efficiently diffuse across the electrode/electrolyte interface. The synergy effects of the high light harvesting of Si nanorod morphology and NiCoSe x electrocatalyst enhanced the production and utilization of photogenerated electrons. The high quality junctions between one-dimensional semiconductor and electrocatalyst for charge collection and utilization is significant to enhance the efficiency of water splitting for hydrogen generation. The improved charge separation and hydrogen evolution reaction kinetics on the electrode-electrolyte interface were confirmed. Furthermore, we expect that inducting the buried junction of Si or optimizing the electrode/electrolyte interface might further boost the PEC-HER performance of the Si/NiCoSe x nanorods, making it a more competitive candidate for PEC-HER photocathode. The reported new Si/NiCoSe x nanorods photocathode offers a new strategy for preparing efficient solar energy conversion devices.