As an increasing number of photocatalysis are developed, non-noble metal photocatalysts that can be synthesized from earth-abundant and low-cost materials have received a great deal of attention. In this study, non-noble metal WS 2 /g-C 3 N 4 photocatalysts were prepared by a facile one-pot synthesis. Varying masses of tungsten disulfide (WS 2 ) were successfully loaded onto g-C 3 N 4 and characterized by X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometry (ICP-OES), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). These results indicated that the WS 2 was successfully synthesized and immobilized closely on the surface of g-C 3 N 4 to form a sheet-like nanostructure . The H 2 generation results showed that the optimal photocatalyst was 0.3-WCN because it had the highest photocatalytic H 2 production of 154 μmol h −1 g −1 , which is 34 times higher than bare g-C 3 N 4 and even higher than 0.3 wt% platinum-loaded g-C 3 N 4 . Additionally, the possible mechanism of the photocatalyst was studied by photoluminescence (PL), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and photoelectrochemical tests, which showed that the WS 2 played a key role in improving the efficiency of separation and migration of the photogenerated carriers in g-C 3 N 4 .
TiO 2 /WS 2 /g-C 3 N 4 composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method. In this process, the WS 2 /g-C 3 N 4 nano-sheets were prepared by liquid-exfoliation method from the bulk WS 2 and C 3 N 4 in the alcohol system, and then the TiO 2 nanoparticles (NPs) grew on the WS 2 /g-C 3 N 4 nano-sheets by in-situ synthesized technique. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange (MO). The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO 2 , g-C 3 N 4 and TiO 2 /g-C 3 N 4 composite. The enhanced photocatalytic activities of TiO 2 /WS 2 /g-C 3 N 4 photocatalysts could be attributed to the synergistic effect of heterostructure between TiO 2 NPs and WS 2 /g-C 3 N 4 nano-sheets, which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons. The quenching tests of radicals indicated that ·O − 2 had crucial effect on degradation of MO, which demonstrated that ·O − 2 was the main active radical in photocatalytic reaction process.
Two-dimensional sulfide is considered as one of the best alternative for noble metal cocatalyst, whereas few-layered 1T WS 2 structure is very helpful to promote the photocatalytical activity for hydrogen generation. Herein, few-layered 1T-WS 2 /g-C 3 N 4 composites have been prepared via a facile one-step calcination route and used as a noble metal-free catalyst for H 2 evolution. The results showed that the optimized 1T-WS 2 /g-C 3 N 4 has a H 2 evolution rate of 10.08 mmol∙g −1 h −1 , which is 180 and 2.44 times larger than that of pure pristine g-C 3 N 4 and g-C 3 N 4 (Pt), respectively. The enhanced photocatalytic activity can be explained as the optimized 1T-WS 2 /g-C 3 N 4 sample has an increased light absorption (from visible to infrared region), better electrical conductivity and high density of active sites. The studies will be helpful for constructing high efficient heterostructured catalysts by loading 1T phase metal dichalcogenides 2D of material onto a two-dimensional material surface.
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