Titanium-coated high-density Fe₂O₃ single crystal nanowire array for solar water splitting

Fe 2 O 3 holds promising n -type semiconductor material in the field of solar water splitting due to its excellent photocatalytic properties. However, the photoelectrochemical performance of Fe 2 O 3 is limited by its inherent properties such as poor conductivity, and charge separation efficiency owing to its recombination rate. Therefore, researchers are more focused on nanostructuring, doping, and surface coating to overcome these issues of Fe 2 O 3 . In this study, we have investigated a low-cost way to fabricate a Ti coating layer on a high-density Fe 2 O 3 single-crystal nanowire array for solar water splitting. Firstly, we have prepared a high-density single-crystal Fe 2 O 3 nanowire array at lower temperatures by a new approach stress-induced atomic diffusion method. Thereafter, the prepared nanowire array was coated by Ti film using RF sputtering. The optimal film thickness of 13 nm titanium coatings layer into Fe 2 O 3 single crystal nanowire array exhibited a high photocurrent density of 1.36 mA/cm 2 at 1.23 V versus RHE and solar to hydrogen conversion efficiency (STH) of 1.67%, which could be resulting from adjusted optoelectronic properties of the nanowires.