Highly efficient visible-light-driven CdS-loaded ZnO-GaN nanowire photoanode fabricated on Si for H2 evolution

被引:5
|
作者
Tariq, Fawad [1 ]
Abdullah, Ameer [1 ]
Kulkarni, Mandar A. [1 ]
Thaalbi, Hamza [1 ]
Jun-Seok-Ha [2 ]
Lee, June Key [2 ]
Ryu, Sang-Wan [1 ,2 ]
机构
[1] Chonnam Natl Univ, Dept Phys, Gwangju 61186, South Korea
[2] Chonnam Natl Univ, Optoelect Convergence Res Ctr, Gwangju 61186, South Korea
基金
新加坡国家研究基金会;
关键词
Vapor-Liquid-Solid; Gallium Nitride Nanowires; Cadmium Sulfide; Photoelectrochemical Water splitting; Photoconversion Efficiency; WATER-SPLITTING PERFORMANCE; SINGLE-STEP FABRICATION; PHOTOELECTRODES; METAL; PHOSPHIDE; MOCVD;
D O I
10.1016/j.jallcom.2023.172901
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
GaN nanowires (NWs) are considered promising photoelectrode materials owing to their direct bandgap, which a high-efficiency photon absorption. Additionally, their conduction and valence bands straddle the water redox level, making them ideal candidates for solar water splitting without external biasing. Moreover, they have a large reactive surface area, which promotes charge separation. However, their practical applicability is limited because of their poor stability and low solar-to-hydrogen conversion efficiency, which can be mitigated by loading a passivation layer and cocatalyst onto the GaN NW surfaces. In this study, CdS/ZnO/GaN NW photoanodes were fabricated on Si substrates for photoelectrochemical water splitting. Vapor-liquid-solid GaN NWs were used as the core material on a Si substrate passivated with a ZnO conformal layer, and CdS was adopted as a cocatalyst. Compared to a ZnO/GaN NW photoanode, the CdS/ZnO/GaN NW photoanode showed a 10-fold increase in photocurrent density and a 47-fold increase in photoconversion efficiency under 1-Sun illumination. We propose that ZnO and CdS inhibit the photocorrosion of bare GaN NWs and thus reduce the surface defects, thereby lowering the photogenerated charge recombination rate. As a result, the stability of GaN NWs in a high pH electrolyte increases, leading to an efficient H2 evolution.
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页数:10
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