The cost-effective deposition of ultra-thin titanium(IV) oxide passivating layers for improving photoelectrochemical activity of SnS electrodes

Abstract

The structures of tin monosulfide (SnS) with the surface modified by ultrathin titanium(IV) oxide layers for potential photoinduced water splitting were successfully fabricated. SnS thin films were deposited onto glass/Mo substrates using high vacuum evaporation (HVE) method, and then a simple and cost-effective deposition-annealing cycling process was used to prepare titanium(IV) oxide passivated SnS structures. The resulting compositional properties were studied using X-ray diffractometry (XRD), Raman spectroscopy, high resolution scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The effects of titanium(IV) oxide layers on the photo-electrochemical (PEC) activity of fabricated p-type SnS thin-film electrodes were examined in this study. The SnS layers passivated with titanium(IV) oxide exhibited reducing the SnS-electrolyte interface resistance, increasing the photocurrent and improving the efficiency of PEC cells as deleterious reactions are inhibited. The various electrochemical methods such as current-voltage measurements, cyclic voltammetry, and electrochemical impedance spectroscopy were used to characterise and analyse SnS structures modified by titanium(IV) oxide.