Photocatalytic Hydrogen Evolution Under Visible Light Using MoS 2 /g-C 3 N 4 Nano-Photocatalysts

Water splitting using solar light and an efficient photocatalyst is one of the new methods of hydrogen production that has attracted much attention today because of its importance in the energy crisis. Hence, a composite material containing molybdenum disulfide (MoS 2 ) and g-C 3 N 4 was synthesized and used in the photocatalytic process. For this purpose, in the first instance, the photocatalytic activity of MoS 2 /g-C 3 N 4 was confirmed by the decolorization pathway of Rhodamine B (Rh B) under visible light irradiation. Then, MoS 2 /g-C 3 N 4 was carefully identified by SEM, XRD, PL, UV–Vis, EDS, and FT-IR analysis. Results of characteristic peaks and composite surface morphology confirm that the structural integrity of the primary photocatalyst sample was intact after combination with MoS 2 despite chemical interactions. The Brunner–Emmet–Teller (BET) surface area, total per valume, and average pore diameter of the sample are close to 15 m 2 g −1 , 0.07 cm 3 g −1 , and 19.5 nm, respectively. Then, the hydrogen production process under solar light was simulated using MoS 2 /g-C 3 N 4 photocatalyst and the Production rate was measured using a gas chromatography system (GC). In addition, the Eosin-Y dye solution is also used as a sensitizer to increase the photocatalyst activity under visible light. The g-C 3 N 4 /MoS 2 -Triethanolamine (TEOA) mixture showed the best quantum efficiency when compared to all other sacrificial agents. Investigation of the factors affecting the catalyst activity showed that the parameters of exposure time, the concentration of photocatalyst, and triethanolamine (TEOA) percent used as a sacrificial agent affect water-splitting reaction efficiency. Further measurements showed that the highest hydrogen production rate of 1905 µmol g −1 h −1 is accessible. Accordingly, the g-C 3 N 4 composite with MoS 2 can be a promising photocatalyst for high-efficiency water splitting. Besides, the photocatalytic mechanism is demonstrated to well-fit into the S-scheme pathway with apparent evidence. Graphical Abstract