Obvious effect of molybdenum supporting on morphology and upconversion luminescence of Er-Yb:TiO2 and improvement of H2 generation for W18O49

Abstract A fascinating strategy of molybdenum ions supporting was utilized to enhance green upconversion (UC) emissions of Er-Yb:TiO2 prepared by sol-gel method. Er-Yb:TiO2 nanoparticles exhibited irregular sizes approximately 100–350 nm, which showed stronger red emission and weaker green emissions under the irradiation of near-infrared (NIR). After molybdenum ions supporting, Er-Yb:TiO2 nanoparticles were turned into uniformly dispersed eight prism structure and average particle size reached about 800 nm. Also, the green UC luminescence integrated intensity of Mo/Er-Yb:TiO2 was about 46 times improved than that of Er-Yb:TiO2. Furthermore, a novel photocatalyst of Mo/Er-Yb:TiO2@W18O49 quasi-core/shell heterostructure was designed based on the localized surface plasmon resonances (LSPR) effect of W18O49 through solvothermal process. With the excitation of NIR, the photocatalytic property of Mo/Er-Yb:TiO2@W18O49 for H2 producing from ammonia borane (BH3NH3) was researched. H2 production was about 2-fold enhancement compared with that of W18O49. Besides, the application of natural sunlight for H2 producing was provided. About 3 times H2 yield was obtained in contrast to that of W18O49. This work provided an effective way to enhance UC luminescence intensity and H2 production efficiency for solving energy deficiency problems.