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Abstract Exploiting effective photocatalytic materials especially co-catalysts is an effective solution to enhance solar hydrogen generation. In this work, we firstly introduce FeSe as highly efficient co-catalyst on the surface of CdS nanoparticles for photocatalytic H 2 evolution under visible light irradiation. The optimized 2 wt% FeSe/CdS composite showed the highest photocatalytic H 2 evolution activity of 204.4 μL/h with an apparent quantum efficiency of 6.71% at 420 nm, which is about 7 times higher than that of pure CdS nanoparticles. More importantly, 2 wt% FeSe/CdS composite also exhibits higher photocatalytic activity than that of 2 wt% Pt/CdS composite under the same condition. The higher photocatalytic H 2 evolution property of FeSe/CdS composite is due to that the photo-generated electrons can be driven by the build-in field and transferred to the surface of FeSe causing electron-hole separation. This work may provide the potential applications of FeSe as a co-catalyst for photocatalytic H 2 evolution. Graphical abstract Image 1 Highlights • FeSe/CdS composites have been successfully synthesized. • The photocatalytic H 2 evolution activity of FeSe/CdS composite is about 7 times of pure CdS nanoparticles. • The photo-generated electrons can be driven by build-in field and transferred to the surface of FeSe. [ABSTRACT FROM AUTHOR]

• A series of BiVO 4 samples composited with NiSe 2 nanosheets were prepared through a facile solvothermal method. • The photocatalytic degradation rate of RhB of the optimized sample reaches 11 times higher than that of pure BiVO 4. • The Schottky junction derived from the discrepancy of work function accelerates the separation of photogenerated carriers. • The interaction at the interface reduces the band gap of BiVO 4. The rapid recombination of photogenerated carriers limits the photocatalytic activity of BiVO 4. Here, we grew NiSe 2 nanosheets on the surface of BiVO 4 through a facile solvothermal method to construct a Schottky junction. Due to the discrepancy of work function, electrons at the interface are transferred from BiVO 4 to NiSe 2 , thereby forming a built-in electric field. In virtue of the built-in electric field and the good conductivity of NiSe 2 , the photo-generated carriers can be quickly separated and transferred. In addition, the interaction at the interface reduces the band gap of BiVO 4 , which increases the absorption of visible light. These above benefits improve the photocatalytic performance. The photocatalytic reaction under visible light shows that the degradation rate of RhB for 9 mol% NiSe 2 composited BiVO 4 increases by 11 times compared with pure BiVO 4. The simplicity of the preparation method and the significantly improved performance show the enormous potential of NiSe 2 to be coupled with other semiconductor photocatalysts to improve their catalytic activity. [ABSTRACT FROM AUTHOR]

Lamellar MoS 2 has attracted widespread attention as a potential electrocatalytic HER (Hydrogen evolution reaction) catalyst. However, it is difficult to further improve its catalytic activity due to two major drawbacks: the limited number of active sites and its poor conductivity. Here, we adopt a one-step method utilizing an ultrafast pulsed laser treatment to produce multiple decorations on lamellar MoS 2 , where nanocrystallization and amorphization of lamellar MoS 2 are achieved simultaneously, along with an additional characteristic of atomic steps. Due to this special microstructure, laser-treated MoS 2 exhibits excellent electrocatalytic performance with a low overpotential and a small Tafel slope (217 mV @ 10 mA cm−2 and 74.5 mV dec−1, respectively), which is superior to that of untreated lamellar MoS 2 (461 mV @ 10 mA cm−2 and 142.6 mV dec−1, respectively). The MoS 2 prepared in this way has a high catalytic activity and a high stability, which indicates potential for electrocatalysis applications. • We proposed a one-step method using ultrafast pulsed laser treatment to enhance the HER performance of lamellar MoS 2. • We prepared ultra-small MoS 2 nanoparticles, amorphization, and atomic steps in situ on lamellar MoS 2. • The performance of treated MoS 2 is far superior to that of MoS 2 before laser treatment. [ABSTRACT FROM AUTHOR]