Enhanced light absorption and charge separation of In-doped ZnO nanorod arrays for photoelectrochemical water-splitting application

초록

Elemental doping promises an efficient strategy to modify and optimize the performance of metal oxide photoanodes. Herein, we introduce a simple hydrothermal method to fabricate In-doped ZnO thin films on the fluorine-doped tin oxide (FTO) to use as a photoanode for water splitting application. The effects of In-doping on the structural, optical, morphological, and electrical properties of ZnO nanorods were studied. PEC results indicate that the 5% In doped ZnO photoanode determined an outstanding photocurrent density reached 0.42 mA/cm(2) at 0.64 V-Ag/AgCl, which is four times higher than the undoped ZnO sample (0.1 mA/cm(2)). Furthermore, Ultraviolet-visible spectroscopy (UV-Vis) and photoluminescence spectroscopy (PL) studies showed a red-shift in the band edge of doped samples compared to the pure samples, which indicate that the light absorption is enhanced. We find that the optimal doping of In (5%) leads to smaller charge transfer resistance and higher electron transfer rate as confirmed from EIS analysis. Therefore, fabricated In-doped ZnO could be a favorable and potential photoelectrode for light-harvesting and water splitting application.

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