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:TiO 2 prepared by sol-gel method. Er-Yb:TiO 2 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:TiO 2 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:TiO 2 was about 46 times improved than that of Er-Yb:TiO 2 . Furthermore, a novel photocatalyst of Mo/Er-Yb:TiO 2 @W 18 O 49 quasi-core/shell heterostructure was designed based on the localized surface plasmon resonances (LSPR) effect of W 18 O 49 through solvothermal process. With the excitation of NIR, the photocatalytic property of Mo/Er-Yb:TiO 2 @W 18 O 49 for H 2 producing from ammonia borane (BH 3 NH 3 ) was researched. H 2 production was about 2-fold enhancement compared with that of W 18 O 49 . Besides, the application of natural sunlight for H 2 producing was provided. About 3 times H 2 yield was obtained in contrast to that of W 18 O 49 . This work provided an effective way to enhance UC luminescence intensity and H 2 production efficiency for solving energy deficiency problems.