Sustainable energy harvesting has emerged as a frontier research area and relentless efforts are being put in to tackle the tenacious issues of global warming and energy crisis. Photoelectrochemical (PEC) water splitting is regarded as a promising technology to produce H. In this study, we report facile fabrication of ZnS modified SrTiO/BiS (STO) heterojunction photoanode for PEC water splitting. Ternary heterojunction photoanode was fabricated using sol-gel followed by SILAR methods. Coupling of wide band gap STO with narrow band gap BiS photosensitizer extends the absorption edge while the ZnS passivation layer improves electrode stability by preventing direct contact of BiS with electrolyte and providing an active energy state for facile charge transfer to improve charge separation. Decreased rate of recombination and elongated lifetime of photogenerated charge carriers resulted in enhanced charge carrier dynamics. STO/BiS/ZnS photoanodes displayed a photocurrent density (J) of 1.89 mA.cm at 1.23 V vs RHE and HC-STH of 1.19% at 0.42 V vs RHE in neutral medium while the corresponding values in basic medium were = 5.08 mA cm at 1.23 V RHE and HC-STH 4.8% at 0.71 V vs RHE; considerably higher than bare STO and binary STO/BiS electrodes. The superior performance in basic medium could be attributed to the presence of hole scavengers. The improved photostability >3000 s was attributed to ZnS deposition. To better under the role of hole scavengers the quantification of O and H was undertaken.

中文翻译：

---

探索 ZnS 作为钝化层在 SrTiO3/Bi2S3 异质结光阳极上的作用，以改善太阳能水分解

可持续能源采集已成为一个前沿研究领域，人们正在不懈努力解决全球变暖和能源危机等棘手问题。光电化学（PEC）水分解被认为是一种有前途的生产氢气的技术。在这项研究中，我们报告了用于PEC水分解的ZnS改性SrTiO/BiS（STO）异质结光阳极的简便制造。三元异质结光电阳极采用溶胶-凝胶法和 SILAR 方法制造。宽带隙 STO 与窄带隙 BiS 光敏剂的耦合扩展了吸收边缘，而 ZnS 钝化层通过防止 BiS 与电解质直接接触并提供有利于电荷转移的活性能态来改善电荷分离，从而提高了电极稳定性。光生载流子复合率的降低和寿命的延长导致载流子动力学增强。在中性介质中，STO/BiS/ZnS 光阳极在 1.23 V vs RHE 下表现出 1.89 mA.cm 的光电流密度 (J)，在 0.42 V vs RHE 下 HC-STH 的光电流密度 (J) 为 1.19%，而在碱性介质中的相应值 = 5.08 mA cm 1.23 V RHE 时，HC-STH 4.8%，0.71 V vs RHE；明显高于裸 STO 和二元 STO/BiS 电极。在碱性介质中的优异性能可归因于空穴清除剂的存在。光稳定性>3000 s的改善归因于ZnS沉积。为了更好地在空穴清除剂的作用下，对 O 和 H 进行了定量。