title: One-pot synthesis of N-F-Cr-doped anatase TiO₂ microspheres with nearly all-(001) surface for enhanced solar absorption.
abstract: The synthesis and clarifications in structure-property relationship for anatase TiO(2) crystals exposing (001) facets have attracted much attention. In this paper, a novel titania microsphere with nearly all-(001) surface was synthesized by hydrothermal treatment of a thermal sprayed TiN/Ti coating with HF aqueous solution containing chromium powders. Unlike the conventional (001)-facet exposed anatase crystals, which are highly truncated bipyramids, the crystal achieved in the current investigation is drum-like with a round cross section. The formation of the drum-like crystals was contributed to a balance between the erosion and precipitation of anatase single crystallites. The Cr-doping in anatase was believed to increase the surface deficiency which enhanced the erosion procedure, leading to the drum-like crystals. The XPS analysis confirmed the incorporations of N, F and Cr in the microsized anatase crystals through the one-pot reaction, which led to a significantly enhanced solar absorption. The UV-Vis diffuse reflectance revealed a band-to-band red-shift of the band gap of the anatase crystals to 1.60 eV, which is contributed mainly to the homogeneous Cr-doping.
authors.affiliation: State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, P. R. China. msewjm@zju.edu.cn
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Wu
authors.forename: Mei-Lan
authors.initials: ML
authors.lastname: Tang
mesh_terms: D000042:Absorption; D002857:Chromium / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009584:Nitrogen / Q000737:chemistry*; D012993:Solar Energy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D002857:Chromium; C009495:titanium dioxide; D005461:Fluorine; C041500:titanium nitride; D014025:Titanium; D009584:Nitrogen