Ternary chalcogenide silver gallium sulfide (AgGaS₂), which has an orthorhombic structure, was already synthesized. However, the feasibility of using the crystal for hydrogen production through photocatalytic water splitting has not been explored. Here, we systematically investigated the structural, electronic, optical, and transport properties of XGaS₂ (X = Ag or Cu) with orthorhombic structure by using the first principles calculations. The band alignments indicate that all calculated absolute potentials of the valence and conduction band edges met the requirement of photocatalytic water splitting reaction. The presence of 2.64 and 2.56 eV direct band energy gaps and obvious optical absorption within the visible light range imply that XGaS₂ can correspond to solar light. Moreover, the large electron mobility and the obvious differences between electron mobility and hole mobility were identified in XGaS₂ structures, which is beneficial to the photocatalytic performance of the water splitting reaction. The present findings can provide a helpful reference for developing novel photocatalytic materials with XGaS₂ for hydrogen generation from water splitting under irradiation of visible light.

中文翻译：

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三元硫属元素化物XGaS2（X = Ag或Cu）用于可见光照射下水分解产生的光催化氢

已经合成了具有正交晶结构的三元硫属元素化物硫化银镓（AgGaS ₂）。然而，尚未探索将晶体用于通过光催化水分解制氢的可行性。在这里，我们通过使用第一性原理计算系统地研究了具有正交晶结构的XGaS ₂（X = Ag或Cu）的结构，电子，光学和传输性质。能带排列表明，所有计算的价带和导带边缘的绝对势均满足光催化水分解反应的要求。2.64和2.56 eV的直接带隙以及在可见光范围内的明显光吸收表明XGaS ₂可以对应太阳光 此外，在XGaS ₂结构中发现了大的电子迁移率以及电子迁移率和空穴迁移率之间的明显差异，这有利于水分解反应的光催化性能。本研究结果可为开发新型的XGaS ₂光催化材料提供参考。XGaS2用于在可见光照射下分解水产生氢。