Enhancing the photoelectrochemical properties of ZnO nanorods through cross-linked polyaniline films

Abstract

This research examines the impact of a conductive polyaniline (PANI) thin film, cross-linked with formaldehyde, on the photoelectrochemical (PEC) capabilities of zinc oxide (ZnO) nanorods (NRs) for water-splitting purposes. The study involved a two-stage process: initially, ZnO NRs were generated on an indium tin oxide (ITO) substrate through a hydrothermal method; subsequently, the cross-linked PANI was produced via chemical polymerization and applied onto the ZnO NRs through spin coating. The crystal structure, surface morphology, and optical properties of the samples were characterized using XRD, SEM, and UV–Vis spectroscopy. The assessment of the PEC performance was carried out through CV and EIS. XRD analysis confirmed the existence of a hexagonal crystal structure of ZnO NRs. SEM analysis indicated a ZnO NRs average diameter of 164.5 nm. The band gap of the ZnO NRs, ZnO NRs/PANI, and ZnO NRs/PANI cross-linked formaldehyde are 3.04 eV, 3.02 eV, and 3.13 eV, respectively. The outcomes revealed that ZnO nanorods coated with cross-linked PANI exhibited the highest current density of 0.66 mA/cm² and a PEC efficiency of 0.41%. Furthermore, the EIS analysis verified that the cross-linked PANI improved the ionic conductivity of the ZnO NRs film. This study contributes to the comprehension of how cross-linked conductive polymers can boost the photoelectrochemical performance of semiconductor materials, presenting a potential strategy to enhance the efficacy of water-splitting devices.