Single crystalline ZnO and TiO₂ nanorods are grown on fluorine-doped tin oxide (FTO) substrates by hydrothermal method. The nanorods are annealed under air and reducing conditions to alter the oxygen nonstoichiometry and hence the mid-bandgap defect states. Such an annealing process is shown to impart significant change on the photoelectrochemical (PEC) performance of the photoelectrodes. Large photocurrent densities (J) of 0.78 mA cm⁻² are obtained for air annealed (AA) TiO₂ nanorods (TNR) compared to hydrogen annealed (HA) TNR (J=0.36 mA cm⁻²). ZnO nanorods (ZNR), on the contrary, shows photocurrent density of 0.76 mA cm⁻² and 0.36 mA cm⁻² for ZNR-HA and ZNR-AA photoanodes, respectively. The contrasting difference in the PEC performance is attributed to the synergetic effect of interfacial impedance with electrolytes and the oxygen nonstoichiometry. Further, to overcome the limitation of light absorption by these materials owing to their wide bandgap, TiO₂ and ZnO nanorods are coated with Sb₂S₃ by chemical bath deposition to form heterostructured TNR-AA/Sb₂S₃(CBD) and ZNR-HA/Sb₂S₃(CBD) thin films. Such heterostructures exhibit enhanced photocurrent values of ∼1.39 mA cm⁻² and 3.36 mA cm⁻² (at 1.6 V versus Ag/AgCl), respectively. The PEC performances of the nanorods are analyzed in terms of the annealing conditions and subsequent introduction of defect states in the bandgap. The present study shows the importance of oxygen defect control at the interface between the oxide and chalcogenide, and its role in the betterment of PEC performance in TiO₂/Sb₂S₃ and ZnO/Sb₂S₃ heterostructure photoanodes.

通过水热法在掺氟氧化锡（FTO）衬底上生长单晶ZnO和TiO ₂纳米棒。纳米棒在空气和还原条件下退火，以改变氧的非化学计量，从而改变中带隙缺陷状态。示出了这种退火工艺对光电极的光电化学（PEC）性能产生了显着变化。与氢退火（HA）TNR（J = 0.36 mA cm ^-2）相比，空气退火（AA）TiO ₂纳米棒（TNR）可获得0.78 mA cm ^-2的大光电流密度（J ）。相反，ZnO纳米棒（ZNR）的光电流密度为0.76 mA cm ^-2和0.36 mA cm ^-2分别用于ZNR-HA和ZNR-AA光阳极。PEC性能的对比差异归因于界面阻抗与电解质和氧气非化学计量的协同效应。此外，为了克服这些材料由于其宽带隙而引起的光吸收限制，通过化学浴沉积用Sb ₂ S ₃涂覆TiO ₂和ZnO纳米棒以形成异质结构的TNR-AA / Sb ₂ S ₃（CBD）和ZNR -HA / Sb ₂ S ₃（CBD）薄膜。这种异质结构显示出增强的光电流值〜1.39 mA cm ^-2和3.36 mA cm ^-2（在1.6 V下，相对于Ag / AgCl）。根据退火条件和带隙中缺陷状态的后续引入分析了纳米棒的PEC性能。本研究表明控制氧化物和硫属元素化物之间的界面处的氧缺陷的重要性，及其在改善TiO ₂ / Sb ₂ S ₃和ZnO / Sb ₂ S ₃异质结构光阳极中PEC性能中的作用。