P‐Si/SnO2/Fe2O3 Core/Shell/Shell Nanowire Photocathodes for Neutral pH Water Splitting. (21st March 2015)

• Record Type: Journal Article
• Authors: Kargar, Alireza; Kim, Sung Joo; Allameh, Paniz; Choi, Chulmin; Park, Namseok; Jeong, Huisu; Pak, Yusin; Jung, Gun Young; Pan, Xiaoqing; Wang, Deli; Jin, Sungho
• Is Part Of: Advanced functional materials. Volume 25:Number 17(2015)
• Page Start: 2609
• Page End: 2615
• Publication Date: 2015-03-21
• Subjects: Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201404571
• Languages: English
• ISSNs: 1616-301X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Silicon is one of the promising materials for solar water splitting and hydrogen production; however, it suffers from two key factors, including the large external potential required to drive water splitting reactions at its surface and its instability in the electrolyte. In this study, a successful fabrication of novel p‐Si/n‐SnO<sub>2</sub>/n‐Fe<sub>2</sub>O<sub>3</sub> core/shell/shell nanowire (css‐NW) arrays, consisting of vertical Si NW cores coated with a thin SnO<sub>2</sub> layer and a dense Fe<sub>2</sub>O<sub>3</sub> nanocrystals (NCs) shell, and their application for significantly enhanced solar water reduction in a neutral medium is reported. The p‐Si/n‐SnO<sub>2</sub>/n‐Fe<sub>2</sub>O<sub>3</sub> css‐NW structure is characterized in detail using scanning, transmission, and scanning transmission electron microscopes. The p‐Si/n‐SnO<sub>2</sub>/n‐Fe<sub>2</sub>O<sub>3</sub> css‐NWs show considerably improved photocathodic performances, including higher photocurrent and lower photocathodic turn‐on potential, compared to the bare p‐Si NWs or p‐Si/n‐SnO<sub>2</sub> core/shell NWs (cs‐NWs), due to increased optical absorption, enhanced charge separation, and improved gas evolution. As a result, photoactivity at 0 V versus reversible hydrogen electrode and a low onset potential in the neutral solution are achieved. Moreover, p‐Si/n‐SnO<sub>2</sub>/n‐Fe<sub>2</sub>O<sub>3</sub> css‐NWs exhibit long‐term photoelectrochemical stability due to the Fe<sub>2</sub>O<sub>3</sub> NCs shell well protection. These results reveal promising css‐NW photoelectrodes from cost‐effective materials by facile fabrication with simultaneously improved photocathodic performance and stability.</p> </abstract>