Particulate photocathode composed of (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15 synthesized with Na2S for enhanced sunlight-driven hydrogen evolution
Particulate photocathode composed of (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15 synthesized with Na2S for enhanced sunlight-driven hydrogen evolution
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DOI：
10.1039/c8se00101d
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发表时间：
2018-08
影响因子：
5.6
通讯作者：
Yosuke Kageshima;T. Minegishi;Y. Goto;H. Kaneko;K. Domen
中科院分区：
文献类型：
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作者：
Yosuke Kageshima;T. Minegishi;Y. Goto;H. Kaneko;K. Domen
采用熔剂法合成了颗粒固溶体(ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15，用不同量的铜前驱体(制备缺铜、化学计量比或过量铜样品)和/或Na2S添加剂，研究了合成条件对光电化学(PEC)性能的影响。用Na2S制备的化学计量比(ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15光电阴极在中性水溶液中产生的阴极光电流比不加Na2S制备的样品大2.3倍。电感耦合等离子体质谱和X射线光电子能谱的元素分析表明，在合成过程中，Na2S的存在除了促进O原子插入Se空位外，还促进了Li从熔剂中进入固溶体。结果表明，经过适当的表面修饰和背接触处理的(ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15光电阴极的起始光电流高达0.77VRHE，在0VRHE时的光电流为−5.2 mA cm−2，在0.37VRHE时的半电池光氢转换效率为1.1%。本研究为高效析氢颗粒铜硫化物光电阴极的制备技术提供了新的见解。
A particulate solid solution, (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15, was synthesized by the flux method using various amounts of a Cu precursor (to make Cu-deficient, stoichiometric, or Cu-excess specimens) and/or a Na2S additive, to assess the effects of synthesis conditions on photoelectrochemical (PEC) properties. A stoichiometric (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15 photocathode prepared with Na2S produced a cathodic photocurrent in a neutral aqueous electrolyte approximately 2.3 times greater than that obtained from a sample made without Na2S. Elemental analyses by inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy demonstrated that the presence of Na2S facilitated the incorporation of Li from the flux into the solid solution, in addition to the insertion of O atoms at Se vacancies, during the synthesis. Consequently, a (ZnSe)0.85(CuIn0.7Ga0.3Se2)0.15 photocathode with appropriate surface modification and back contact demonstrated an onset potential for cathodic photocurrent as high as 0.77 VRHE, a −5.2 mA cm−2 of photocurrent at 0 VRHE and a half-cell solar-to-hydrogen conversion efficiency of 1.1% at 0.37 VRHE. The present study provides new insights into techniques for the preparation of particulate Cu-chalcogenide photocathodes for efficient hydrogen evolution.