The effects of adjusting pulse anodization parameters on the surface morphology and properties of a WO3 photoanode for photoelectrochemical water splitting
The effects of adjusting pulse anodization parameters on the surface morphology and properties of a WO3 photoanode for photoelectrochemical water splitting
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DOI：
10.1007/s10008-018-3911-5
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发表时间：
2018-02
影响因子：
2.5
通讯作者：
Huidan Lu;Yi Yan;Mengying Zhang;Haijun Tan;P. Geng;S. Le;Zhishu Yang;Yongping Liu
中科院分区：
文献类型：
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作者：
Huidan Lu;Yi Yan;Mengying Zhang;Haijun Tan;P. Geng;S. Le;Zhishu Yang;Yongping Liu
有序的多孔纳米结构提供了一个大的反应界面，具有异常多的活性位点，这意味着这种纳米结构特别适用于光化学（PEC）水分解。因此，我们采用方波开/关电压脉冲阳极氧化法在W箔上制备了wo3薄膜，并考察了反应参数（特别是占空比、频率和F离子含量）对薄膜表面形貌和PEC行为的影响。当脉冲电压为50 V，占空比为20%，脉冲频率为200 Hz时，在0.06 M NH4F的电解液中制备的wo3薄膜具有有序的多孔形貌。在优化条件下制备的wo3薄膜在0.5 M na2so4电解液中暴露于AM 1.5 G 1-sun光照下，在1.2 V偏压下产生了1.33 mA cm - 2的水分解光电流密度。有序多孔wo3薄膜的高PEC活性可归因于其有序的多孔纳米结构，这使得其比致密或无序的多孔结构具有更大的表面积。此外，有序多孔wo3薄膜还表现出优异的稳定性，在350 nm和1.2 V的偏置电位下具有57.8%的入射光子-电荷转换效率（IPCE）。本研究表明，脉冲阳极氧化技术可以控制制备用于PEC水氧化的多孔wo3纳米结构。
An ordered porous nanostructure provides a large reaction interface with an unusually high number of active sites, meaning that such a nanostructure is especially applicable to photoelectrochemical (PEC) water splitting. Therefore, we prepared WO3films on W foil by pulsed anodization using square-pulse on/off voltage followed by calcination, and scrutinized the effects of reaction parameters—particularly the duty ratio, frequency, and F−ion content—on the surface morphology and PEC behavior of the films. The WO3films produced with a pulsed voltage of 50 V, a duty ratio of 20%, and a pulse frequency of 200 Hz in an electrolyte of 0.06 M NH4F showed an ordered and porous morphology. WO3films prepared under optimized conditions yielded a water splitting photocurrent density of 1.33 mA cm−2at a bias potential of 1.2 V when exposed to AM 1.5 G 1-sun illumination in 0.5 M Na2SO4electrolyte. The high PEC activity of the ordered porous WO3films can be attributed to their ordered porous nanostructure, which results in a much larger surface area than in compact or disordered porous structures. Moreover, the ordered porous WO3films also exhibited excellent stability and a high incident-photon-to-charge conversion efficiency (IPCE) of 57.8% at 350 nm and a bias potential of 1.2 V. This research demonstrates that the pulsed anodization technique allows the controlled fabrication of porous WO3nanostructures for application in PEC water oxidation.