Composite of titanium dioxide nanotube and cobalt sulfide for photoelectrochemical application

Abstract

TiO2 nanotubes (NT) offer several advantages over other geometries for photoelectrochemical (PEC) applications. However, their performance in PEC water-splitting application has remained unsatisfactory due to its wide bandgap. To address this limitation, one approach is the incorporation of other materials as co-catalysts. Hence, in this study, a composite of TiO2 NT and cobalt sulfide (Cox Sy ) was successfully synthesized, and its potential as a photoelectrode for water molecules splitting was evaluated. The TiO2 NT was synthesized using electrochemical anodization of Ti foil, followed by annealing at 500 °C. Subsequently, Cox Sy was added to the TiO2 NT using hydrothermal method, and the composite was further annealed at 400 °C. Characterization technique, such as FESEM and XRD were employed to identify the morphological and phase structures, while UV-Vis reflectance spectroscopy was used for optical analysis. The efficiency of Cox Sy deposited on to TiO2 NT were evaluated by measuring the photocurrent generation. Remarkably, the sample of 60_Cox Sy /TiO2 NT exhibited photocurrent as high as 0.375 mA/ cm2 which is over sixfold higher than the bare TiO2 NT. The results reported in this study were higher than those reported previously.