Nanostructured Bi2S3/WO3 heterojunction films exhibiting enhanced photoelectrochemical performance
Nanostructured Bi2S3/WO3 heterojunction films exhibiting enhanced photoelectrochemical performance
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DOI：
10.1039/c3ta13239k
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发表时间：
2013-01-01
影响因子：
11.9
通讯作者：
Mullins, C. Buddie
中科院分区：
文献类型：
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作者：
He, Huichao;Berglund, Sean P.;Mullins, C. Buddie
为了提高WO3的光电化学活性，通过将WO3薄膜与不同数量的海胆状Bi2S3纳米球耦合来设计Bi2S3/WO3异质结薄膜。 WO3薄膜由WO3纳米棱柱阵列组成，采用溶剂热法合成。在WO3薄膜上涂覆单层Bi2S3后，所得Bi2S3/WO3异质结薄膜表现出增强的光电化学活性。在1.2 V vs. Ag/AgCl条件下，一层Bi2S3的Bi2S3/WO3异质结薄膜在0.1 M Na2SO4中的初始光电流密度为1.33 mA cm(-2)，在0.2 M NaCl混合水-乙醇溶液中为1.19 mA cm(-2)，分别比相同条件下的裸WO3薄膜高40%和32%。与 WO3 薄膜耦合的最佳 Bi2S3 层数为 3 层，其具有最高的光电流密度和 IPCE 值。 Bi2S3/WO3异质结薄膜的光电化学活性由于在水性电解质中的光腐蚀而对水氧化不稳定，但在NaCl混合水-乙醇溶液和含有碘化物/三碘化物作为氧化还原对的非水溶液中稳定。 Bi2S3/WO3异质结膜光电化学活性增强的根源主要归因于WO3和Bi2S3之间的带电势匹配，这有利于电荷分离。
To improve the photoelectrochemical activity of WO3, Bi2S3/WO3 heterojunction films were designed by coupling WO3 films with varying amounts of urchin-like Bi2S3 nanospheres. The WO3 films were composed of WO3 nanoprism arrays, which were synthesized using a solvothermal method. After coating a single layer of Bi2S3 on top of the WO3 film, the resulting Bi2S3/WO3 heterojunction film showed enhanced photoelectrochemical activity. At 1.2 V vs. Ag/AgCl, the initial photocurrent density of the Bi2S3/WO3 heterojunction film with one layer of Bi2S3 was 1.33 mA cm(-2) in 0.1 M Na2SO4 and 1.19 mA cm(-2) in a 0.2 M NaCl mixed water-ethanol solution, which was 40% and 32% higher than the bare WO3 film under the same conditions, respectively. The optimal number of Bi2S3 layers for coupling with the WO3 film was found to be 3 layers, which had the highest photocurrent density and IPCE values. The photoelectrochemical activity of Bi2S3/WO3 heterojunction film was not stable for water oxidation due to photocorrosion in aqueous electrolyte, but it was stable in the NaCl mixed water-ethanol solution and a non-aqueous solution containing iodide/triiodide as a redox couple. The origin of enhanced photoelectrochemical activity of the Bi2S3/WO3 heterojunction film was primarily ascribed to the band potential matching between WO3 and Bi2S3, which is advantageous for charge separation.