Enhanced photoelectrochemical performance of tin oxide decorated tungsten oxide doped TiO2 nanotube by electrodeposition for water splitting

Abstract

Abstract Titanium substrate was subjected to anodization and electrodeposition techniques to prepare tin oxide decorated tungsten oxide doped TiO2 nanotube (Sn-WTNT) films. Then, they were used as photoanodes in photoelectrochemical (PEC) water splitting to produce hydrogen. The samples were characterized by different techniques including field emission scanning and transmission electron microscopies (FE-SEM and TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), UV–Vis DRS and Raman spectroscopies. The photoelectrochemical behavior of the samples was studied by linear sweep voltammetry (LSV) and chronoamperometry. Furthermore, the impact of tin electrodeposition time on the photocatalytic behavior of the Sn-WTNT photoelectrodes in PEC water splitting has been investigated. The highest PEC activity was shown by WT5 photoelectrode, (WT5 = Sn-WTNT which was prepared after 10 min of tin electrodeposition and subsequent treatments). Also, the photochemical stability of all samples was maintained in all photocatalytic tests, even after four cycles. The effect of different alcohol additives on the electrolyte was also studied. The rate of hydrogen evolution by Sn-WTNT decreased as follows: ethylene glycol > glycerol > methanol > ethanol > propanol > butanol > pentanol. H2 production rates were observed to be influenced by the number of hydroxyl groups, polarity, and relative hole scavenging capability of the alcohols.