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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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