SnS2/TiO2 Nanocomposites for Hydrogen Production and Photodegradation under Extended Solar Irradiation

Abstract

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.

Recent Progress and Approaches on Transition Metal Chalcogenides for Hydrogen Production

“…Combined peaks of both SnS 2 and TiO 2 were observed with the 5, 10, 15, and 20 wt. % SnS 2 /TiO 2 (ST-5, ST-10, ST-15, and ST-20, respectively) nanocomposite and confirmed the good impregnation of SnS 2 on TiO 2 in their study [106]. In addition, the particle size distribution can also be easily ease, and thus, many of the reported works have used this simple nique to study the TMC materials using SEM.…”

“…The surface morphology of these SnS 2 /TiO 2 nanocomposites at different wt. % possessed nanosheets, and it can be seen that the sponge-like materials covered the structure and, therefore, exhibited significant aggregation [106].…”

Potential transition and post-transition metal sulfides as efficient electrodes for energy storage applications: review

“…1b. 39,40 In the past few years, transition metal sulde-based nanomaterials have been extensively studied in supercapacitors, [41][42][43] solar cells, 44,45 hydrogen production, 46 lithium-ion batteries, 47 and catalytic 48,49 applications. Furthermore, transition and posttransition metal suldes (TMSs) have attracted attention due to their potential as pseudocapacitive materials for capacitors owing to their high specic capacitance, low cost, large global abundance, [50][51][52][53][54] greater conductivity than their oxide and hydroxide counterparts, 55,56 and rich redox reactions.…”

Cost Effective Solvothermal Method to Synthesize Zn-Doped TiO2 Nanomaterials for Photovoltaic and Photocatalytic Degradation Applications

“…Photocatalytic degradation of MB solution was performed using undoped and 0.5, 1.0, 1.5, and 2.0 mol% Zn-doped TiO 2 nanomaterials. As reported in our previous study [49], 25.0 mg of the photocatalyst was suspended in 50 mL of MB solution (initial concentration was 10 ppm) under direct sunlight (intensity of ~100 mWcm −2 ). Prior to irradiation, the MB solution with photocatalyst was stirred in the dark for 30 min to ensure the establishment of adsorption or desorption equilibrium.…”