摘要
以氯化醇钛盐表面反应法制备系列TiO2/SiO2,根据XRD,Raman和DRS表征分析,载体表面具有分子级分散的锐钛矿型TiO2微晶粒子和非晶TiOx物种。与本体TiO2相比,TiO2/SiO2的吸收带边显著蓝移,能隙增大为3.96eV。当金属M(M:Pd,Cu和Ni)负载于TiO2/SiO2表面,可使其光吸收域扩展到可见光区,并引起吸收带边红移。相对Pd的负载,Cu,Ni的负载对TiO2/SiO2的LMCT带影响更大,其中Cu-TiO2/SiO2的能隙减小为3.68eV。当金属氧化物MoO3负载于TiO2/SiO2上时,可以调变TiO2/SiO2的吸收带边并增强对可见光的吸收;随MoO3载量的增加,表面物种的相互作用增强,形成Mo-O-Ti复合结构,增强了LMCT带的吸收强度,并使能隙减小为3.81eV。
TiO2/SiO2 were prepared by surface reaction of silica with an acetone solution of Ti（i-OC3 H7 ）nCl4-n, where n=0-2. Results of XRD, Raman and UV-Vis DRS showed that two types of Ti species, small particles of anatase-type TiO2 and noncrystalline TiO2 species, are molecularly dispersed on the silica surface. Relative to the TiO2 bulk, a blue-shift in the bandgap adsorption edge of TiO2/SiO2 was observed due to the quantum size effects. The bandgap energy （Eg） of TiO2/SiO2 is 3. 96 eV. When M（Pd, Cu, Ni） is deposited on TiO2/SiO2, the adsorption spectra extend to visible light region and the bandgap adsorp-tion edge red shifts with respect to TiO2/SiO2. Compared with that of Pd, the deposition of Cu and Ni on TiO2/SiO2 has more effects on LMCT transition （O^2→Ti^4＋ ） of Ti atoms. And the bandgap energy of Cu-TiO2/SiO2 decreases to 3.69 eV. Similarly, the photon adsorption property for visible light can be improved relatively by the incorporation of MoO3 on TiO2/SiO2, At higher MoO3 loadings, the Mo-O-Ti coupled structure can be formed through the interaction between MoO3 and TiO2, which made the bandgap energy decrease to 3.81 eV.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2007年第4期720-724,共5页
Spectroscopy and Spectral Analysis
基金
国家重大基础研究前期研究专项(2001CCAO3600)
国家重点基础研究专项(2003CB214500)资助
