Investigating the Photoelectrochemical Performance of WO₃-TiO₂ Nanorod Photoanodes in Water Splitting<strong> </strong>

TiO2 nanorod as a superior nanostructure has attracted a lot of attention to exert in the photocatalytic and photoelectrocatlytic applications in recent years. Nevertheless, its practical usage is restricted by a number of limitations such as the large band gap energy, the low rate of photo-induced carriers generation and the high rate of charge carriers recombination. Therefore in this study, incorporation of TiO2 nanorod with WO3 is proposed as a suitable approach to overcome these defects. In this regard, WO3-TiO2 nanorod was constructed by a facile one pot hydrothermal method in two incessant steps and was then employed as a potent photoanode for photoelectrocatalytic hydrogen generation. The morphology, elemental compositions and optical properties were characterized by the FESEM, EDS and DRS analysis, respectively. Furthermore, voltammetry analyses were performed to assay the photoelectrochemical features of WO3-TiO2 nanorod. The results confirmed that the incorporation of TiO2 nanorod with WO3 not only significantly made the band gap energy narrower (from 3eV to 2eV), but also dramatically intensified the photocurrent density and photoconversion efficiency from 1mA.cm-2 to 1.8mA.cm-2 and from 0.3% to 0.45%, respectively. As a consequence of improving optical properties and photoelectrochemical features, WO3-TiO2 nanorod could generate 2.43 mmol H2 during 100 min under UV irradiation, which was 1.71 times more than hydrogen generated over pure TiO2 nanorod