Facile preparation of nanocrystalline TiO_2 thin films using electrophoretic deposition for enhancing photoelectrochemical water splitting response

摘要

Titanium oxide (TiO_2) nanocrystalline particles have been successfully deposited on fluorine-doped tin oxide (FTO) glass using an electrophoretic deposition (EPD) with a good uniformity. This study aims to optimize the heat treatment temperature, applied electric field, and deposition time to produce a good uniformity nanocrystalline TiO_2 layer coating on FTO glass for better photoelectrochemical water splitting hydrogen generation performance under UV irradiation. In the present study, EPD technique allows controlling of TiO_2 nanocrystalline layer characteristics on FTO glass, including smoothness and thickness. Characterisation like FE-SEM revealed that nanocrystalline TiO_2 with a 14.6 μm thickness with good uniformity and minimal cracking surface exhibited the highest photocurrent density (2.12 mA/cm~2) among samples. Besides, Raman and XRD analyses showed that nanocrystalline TiO_2 thin coating form successfully. Based on our experiments, we proposed that the optimum condition to form nanocrystalline TiO_2 thin film layer using EPD technique is 30 V, 60 s of deposition and post-annealing of the thin film at 400 °C based on the j_p-V characteristic. Under illumination of 100 W UV light, the photoconversion efficiency can be up to 2.49%. In addition, hydrogen production was tested with the production rate is up to 0.45 mL/cm~2/h and the photoelectrode can be re-used and remained stable for five cycles continuously.