Investigation of Sn_1-xCo_xS nanocomposites as a catalyst for hydrogen production from sodium borohydride methanolysis

Samples of Sn_1-xCo_xS (x = 0, 0.025, 0.075, 0.1) were synthesized via the thermal evaporation approach under N₂ gas. The phase characterization of the synthesized samples was conducted employing HighScore plus software. The quantitative assessment of the resulting phases and their structure and microstructure parameters were determined using Rietveld refinement methodology. The SEM images validated the formation of two-dimensional sheets firmly stacked in building blocks, and the corresponding EDS analysis substantiated the incorporation of Co ions in the samples. FTIR and Raman spectroscopic techniques were utilized to corroborate the established phases, chemical composition and the inclusion of Co within the samples. The impact of doping on the absorption and reflectance features of Sn_1-xCo_xS samples was investigated. The substantial absorption that forms a plateau in the visible range suggests that all samples possess the capability for effective utilization of visible light. In the UV and visible regions, the sample with x = 0.025 revealed the highest absorbance, while in the IR region, the sample with x = 0.1 displayed the peak absorbance value. The lowest optical band gap energy values (1.15 and 3.38 eV) were obtained at x = 0.075. The influence of nano Sn_1-xCo_xS samples on the rate of hydrogen generation through the utilization of sodium borohydride (NaBH₄) is explored. Sample containing 10% Co exhibits the highest generation rate at 59382 mL min⁻¹g⁻¹.