S/TiO_2纳米氧敏材料的结构与吸脱附特性  

Structure and characteristics of adsorption and desorption for S-doped TiO_2 as an oxygen sensor

作　　者：韩志钟[1] 潘海波[1] 沈水发[1] 李世云[1] 

机构地区：[1]福州大学功能材料研究所,福州350002

出　　处：《功能材料与器件学报》2008年第4期780-786,共7页Journal of Functional Materials and Devices

基　　金：国家自然科学基金(50472001);福建省重大专项(2005HZ01-2-6);福州大学引进人才基金资助

摘　　要：以TiC l3为钛源,采用溶胶-凝胶法,在500℃(1h)烧结获得非金属离子(硫)掺杂TiO2的纳米粉体,利用XRD,FT-IR,UV-vis,ESEM,Zeta电位,XRF,TPD等表征S/TiO2结构特性。结果表明,硫掺杂有利于其向金红石相转变,低掺杂浓度(2at%)时,硫主要以S4+形式存在,当掺杂量为25at%时,部分掺杂硫以S2-形式替代O2-,由于两者间的电负性差异,导致表面上Ti3+、Ti4+周围的电子云密度增加,从而提高样品对氧气的吸附活性,使其表面的富余电子向吸附氧转移,提高了氧敏特性。S/TiO2敏感体表面的吸附氧以氧分子形式脱附(≤550℃),而在高温(≥600℃)下主要以SO2形式脱附。Nonmetallic ions （S） doped TiO2 nanomaterials were prepared by sol - gel technique using TiCl3 and calcined at 500℃ for lh. Structural properties of S -doped TiO2 were characterized by XRD, FT - IR, UV - vis, ESEM, Zeta potential, XRF, TPD. The results show that doping sulfur is favorable to phase transformation from anatase to rutile. The Sulfur is in the primary form of S^4＋ with lower concentration （2at%）, while concentration of dopant is up to 25at%, some O^2- anions in the lattice are substituted by S^2- . For the difference of electronegativity between oxygen and sulfur, the density of Ti^3＋ or Ti^4＋ electronic cloud on the surface is increased. Further, it improved activity of oxygen adsorption and redundant electrons on the surface are transferred to adsorptive oxygen. At last, the oxygen sensitivity for an oxygen sensor based on S/TiO2 is enhanced. Adsorptive oxygen on the surface of S/TiO2 is desorbed in oxygen molecule （ ≤ 550℃ ）, but in SO2 at higher temperature（ ≥ 600℃）.

关 键 词：TIO2 S掺杂 氧敏特性 吸附 

分 类 号：TB381[一般工业技术—材料科学与工程]