Facile synthesis of VS2/CdS/NaYF4: Yb, Er ternary heterojunctions for the visible-near-infrared-light driven photocatalysis

Developing an efficient chalcogenide photocatalyst with a broad spectral response, rapid energy and charge transfer by integrating upconversion materials and visible-light-driven photocatalyst are significant to alleviate the pressure of environmental treatment. Herein, the heterojunctions of CdS with VS2 as co-catalyst (electron transport medium) and NaYF4: Yb, Er (NYYE) upconversion material were constructed by hydrothermal method and the nanostructures were investigated, in which CdS nanoparticles are composed of cubic and hexagonal CdS with high crystallinity. Interestingly, the as-prepared VS2/CdS/NYYE heterojunctions exhibited splendid photocatalytic performance on the degradation Rh B dye for the efficiency of 97.31% under visible-near infrared light irradiation for 150 min. It could give the credit to the synergic effect of the enhanced interface energy transfer of upconversion material and the co-catalysis of VS2 among VS2, NYYE and CdS, where the heterojunctions could induce the efficient separation of photogenerated carriers and the emergence of high oxidative species (center dot O-2(-) and h(+)). The alternative mechanisms of carriers and energy transfer were also discussed.