Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water?Splitting

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	Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water?Splitting
	Y. F. Zhao; P. Y. Chen; B. S. Zhang; D. S. Su; S. T. Zhang; L. Tian; J. Lu; Z. X. Li; X. Z. Cao; B. Y. Wang; M. Wei; D. G. Evans; X. Duan
	2012
发表期刊	Chemistry-a European Journal
ISSN	0947-6539
卷号	18 期号:38 页码:11949-11958
摘要	A family of photocatalysts for water splitting into hydrogen was prepared by distributing TiO6 units in an MTi-layered double hydroxide matrix (M=Ni, Zn, Mg) that displays largely enhanced photocatalytic activity with an H2-production rate of 31.4 mu mol?h-1 as well as excellent recyclable performance. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) mapping and XPS measurement reveal that a high dispersion of TiO6 octahedra in the layered doubled hydroxide (LDH) matrix was obtained by the formation of an M2+-O-Ti network, rather different from the aggregation state of TiO6 in the inorganic layered material K2Ti4O9. Both transient absorption and photoluminescence spectra demonstrate that the electronhole recombination process was significantly depressed in the Ti-containing LDH materials relative to bulk Ti oxide, which is attributed to the abundant surface defects that serve as trapping sites for photogenerated electrons verified by positron annihilation and extended X-ray absorption fine structure (EXAFS) techniques. In addition, a theoretical study on the basis of DFT calculations demonstrates that the electronic structure of the TiO6 units was modified by the adjacent MO6 octahedron by means of covalent interactions, with a much decreased bandgap of 2.1 eV, which accounts for its superior water-splitting behavior. Therefore, the dispersion strategy for TiO6 units within a 2D inorganic matrix can be extended to fabricate other oxide or hydroxide catalysts with greatly enhanced performance in photocatalysis and energy conversion.
部门归属	[zhao, yufei; chen, pengyun; zhang, bingsen; tian, lei; li, zhuoxin; wei, min; evans, david g.; duan, xue] beijing univ chem technol, state key lab chem resource engn, beijing 100029, peoples r china. [zhang, bingsen; su, dang sheng] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [li, zhuoxin; cao, xingzhong; wang, baoyi] chinese acad sci, inst high energy phys, beijing 100049, peoples r china.;wei, m (reprint author), beijing univ chem technol, state key lab chem resource engn, beijing 100029, peoples r china.;weimin@mail.buct.edu.cn
关键词	Double Hydroxides Layered Compounds Photochemistry Titanium Water Splitting Visible-light Irradiation Transient Absorption-spectroscopy Photocatalytic Activity Hydrogen-production Titanium-dioxide Mesoporous Silica Calcium Niobate Co Oxidation Water Nanoparticles
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文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/60490
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. F. Zhao,P. Y. Chen,B. S. Zhang,et al. Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water?Splitting[J]. Chemistry-a European Journal,2012,18(38):11949-11958.
APA	Y. F. Zhao.,P. Y. Chen.,B. S. Zhang.,D. S. Su.,S. T. Zhang.,...&X. Duan.(2012).Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water?Splitting.Chemistry-a European Journal,18(38),11949-11958.
MLA	Y. F. Zhao,et al."Highly Dispersed TiO6 Units in a Layered Double Hydroxide for Water?Splitting".Chemistry-a European Journal 18.38(2012):11949-11958.