Design, Synthesis And Characterization Of Highly Active Ti-based Photocatlysts

Titanium based semiconductor photocatalyts are generally wide band semiconductors with a negative enough conducting band minimum and positive enough valance band maximum, which will provide powerfull electrons and holes to facilite photocatalytic redox reactions. The low photocatalytic quatum efficiency of photocatalyst is the main obstacle to its better photocatalytic performance. Factors that will influence the quantum efficiency of photocatalysts includes crystallinity, size, crystal defects and band structure of photocatalytic material. Besides, the differences of atmic arrangement of variform crystal facets can result in the differences of electronic structure as well as photocatalytic activity amoung crystal facets. This article is aimed to design and synthesize photocatalysts with improved activity. Micro-sized anatase TiO2 particles were synthesized by using a green hydrothermal method according to crytal growth thoery. Multi-component heterostructures of Cu-Cu2O-TiO2 and SrTiO3-WO3-Ru/Rh were designed and fabricated according to band engineering theory, lattice match theory and crystal growth theory, with the aim of improving electron-hole separation and photocatalytic efficiency of the mateial.Anatase TiO2 exposed by {001} facets were successfully synthesised by using a new hydtothermal method. In this synthetic process, EDTA and F are both act as synergetic morphology controlling agent. The crystallographic structure as well as the growth mechanism of anatse TiO2 particles were investigated by XRD/SEM/TEM/XPS, respectively.Multi-component Cu-Cu2O-TiO2-nanojunctions were successfully synthesized with a mild chemical process, and their structure and composition were thoroughly analyzed by XRD/TEM/FESEM/XPS. The as-prepared solid-state Z-scheme Cu-Cu2O-TiO2 nanojunctions demonstrated enhanced photocatalytic properties, which was resulted from the optimized transmission ways of electrons and holes.Solid state Z-scheme SrTiO3-WO3-Ru/Rh heterojunctions were fabricated by using a three-step method. The crystallographic structure, composition and structure of the as obtained material were analyzed by XRD/FESEM. The spectral characteristic were analyzed by UV-vis spectrum. Photocatalytic water splitting tests were used to systematicly investigate the material photocatalytic performance. This work demonstrate that the electron-hole transmission way and material structure have obvious influences on material photocatalytic performance.