Gun'ko V M, Blitz J P, Zarko V I, Turov V V, Pakhlov E M, Oranska O I, Goncharuk E V, Gornikov Y I, Sergeev V S, Kulik T V, Palyanytsya B B, Samala R K
Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kiev, Ukraine.
J Colloid Interface Sci. 2009 Feb 1;330(1):125-37. doi: 10.1016/j.jcis.2008.10.049. Epub 2008 Nov 1.
Morphological, structural, adsorption, and catalytic properties of highly disperse titania prepared using sulfate and pyrogenic methods, and fumed titania-containing mixed oxides, were studied using XRD, TG/DTA, nitrogen adsorption, (1)H NMR, FTIR, microcalorimetry on immersion of oxides in water and decane, thermally stimulated depolarization current (TSDC) and catalytic photodecomposition of methylene blue (MB). Phase composition and aggregation characteristics of nanoparticles (pore size distribution) of sulfate and pyrogenically prepared titania are very different; temperature dependent structural properties are thus very different. Catalytic activity for the photodecomposition of MB is greatest (per gram of TiO(2) for the pure oxide materials) for non-treated ultrafine titania PC-500, which has the largest S(BET) value and smallest particle size of the materials studied. However, this activity calculated per m(2) is higher for PC-105, possessing a much smaller S(BET) value than PC-500. The activity per unit surface area of titania is greatest for the fumed silica-titania mixed oxide ST20. Calcination of PC-500 at 650 degrees C leads to enhancement of anatase content and catalytic activity, but heating at 800 and 900 degrees C lowers the anatase content (since rutile appears) and diminishes catalytic activity, as well as the specific surface area because of nanoparticle sintering.
采用XRD、TG/DTA、氮吸附、（1）H NMR、FTIR、氧化物在水和癸烷中浸渍的微量热法、热刺激去极化电流（TSDC）以及亚甲基蓝（MB）的催化光分解等方法，研究了用硫酸盐法和热解法制备的高分散二氧化钛以及含气相二氧化钛的混合氧化物的形态、结构、吸附和催化性能。硫酸盐法和热解法制备的二氧化钛纳米颗粒的相组成和聚集特性（孔径分布）差异很大；因此，与温度相关的结构性质也有很大不同。对于未处理的超细二氧化钛PC - 500，其光催化分解MB的活性最大（对于纯氧化物材料，以每克TiO₂计），该材料在所研究的材料中具有最大的S（BET）值和最小的粒径。然而，以每平方米计算，PC - 105的活性更高，其S（BET）值比PC - 500小得多。对于气相二氧化硅 - 二氧化钛混合氧化物ST20，二氧化钛单位表面积的活性最大。在650℃下煅烧PC - 500会导致锐钛矿含量增加和催化活性增强，但在800℃和900℃下加热会降低锐钛矿含量（因为出现了金红石），并降低催化活性以及比表面积，这是由于纳米颗粒烧结所致。
