Enhanced catalytic property of metal oxide for an efficient visible-induced photoelectrochemical water splitting

Sn-doped ZnO nanorods (NRs) were grown on a conductive iodine-doped tin oxide substrate with a cost-effective two-step method (sol–gel and hydrothermal). The effect of varying concentration of dopants on morphology and photocurrent density is closely investigated. For microstructural and optical analysis, the bare and Sn-doped ZnO NRs were subjected to field emission scanning electron microscope (FESEM), energy-dispersive spectroscopy, X-ray diffraction, UV–Vis, and Raman spectroscopy. The presence of the most intense peak directed to (0002) plane confirmed the growth of ZnO NRs and their vertical alignment towards c-axis. The impact on nucleation density and morphology due to the addition of dopant was revealed by the FESEM images. The Raman analysis also confirmed the wurtzite nature of ZnO NRs along with the impact of dopant in its crystallinity. The aim of this work was to ameliorate the capability of absorbing solar light in the visible range. Sn_0.05Zn_0.95O exhibited highest photocurrent density among all the doped samples with 0.199% photo-conversion efficiency under visible-light illumination. Therefore, the synthesised Sn_0.05Zn_0.95O seems to be an efficient candidate for photoelectrochemical water-splitting application.