A particulate solid solution, (ZnSe)_0.85(CuIn_0.7Ga_0.3Se₂)_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(CuIn_0.7Ga_0.3Se₂)_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(CuIn_0.7Ga_0.3Se₂)_0.15 photocathode with appropriate surface modification and back contact demonstrated an onset potential for cathodic photocurrent as high as 0.77 V_RHE, a −5.2 mA cm⁻² of photocurrent at 0 V_RHE and a half-cell solar-to-hydrogen conversion efficiency of 1.1% at 0.37 V_RHE. The present study provides new insights into techniques for the preparation of particulate Cu-chalcogenide photocathodes for efficient hydrogen evolution.

中文翻译：

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由Na ₂ S合成的（ZnSe）_0.85（CuIn _0.7 Ga _0.3 Se ₂）_0.15组成的颗粒光电阴极，用于增强太阳光驱动的氢气释放

通过助熔剂法，使用各种量的Cu前体（以制备Cu不足，化学计量或Cu过量的样品）和/或通过助熔剂法合成颗粒状固溶体（ZnSe）_0.85（CuIn _0.7 Ga _0.3 Se ₂）_0.15 Na ₂ S添加剂，以评估合成条件对光电化学（PEC）性能的影响。用Na ₂制备的化学计量（ZnSe）_0.85（CuIn _0.7 Ga _0.3 Se ₂）_0.15光电阴极S在中性水性电解质中产生的阴极光电流约为从不含Na ₂ S的样品中获得的阴极光电流的2.3倍。通过电感耦合等离子体质谱法和X射线光电子能谱进行的元素分析表明，Na ₂ S的存在促进了Na ₂ S的存在。在合成过程中，除了在Se空位处插入O原子外，还将Li从助熔剂中引入到固溶体中。因此，具有适当表面改性和背面接触的（ZnSe）_0.85（CuIn _0.7 Ga _0.3 Se ₂）_0.15光电阴极显示出高达0.77 V _RHE的阴极光电流的起始电位在0 V _RHE时为-5.2 mA cm ^-2的光电流，在0.37 V _RHE时半电池的太阳能转化为氢的效率为1.1％。本研究提供了新的见解，为有效的氢放出制备颗粒状铜硫族化物光电阴极的技术。