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TiO2纳米粒子膜表面性质的研究 总被引:14,自引:0,他引:14
TiO_2纳米粒子膜在光催化降解大气和水中的污染物[1]、光电转换[2]、光致变色[3]等方面有广阔的应用前景,近年来受到了科学界的高度重视.研究表明,膜的表面性质对如上应用有着重要影响.本文采用等离子体化学气相沉积法(PECVD法)[4]制备了TiO2的纳米粒子膜,分别采用TiCl4等离子体或O2等离子体处理膜表面,获得两种不同表面性质的TiO2纳米粒子膜;并利用表面光电压谱(SPS)和电场诱导表面光电压谱(EFISPS)技术对膜的表面性质进行具体分析,探讨了其在光催化领域的可能应用.1实验部… 相似文献
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纳米TiO2微胶粒的光化应制备机理及量子尺寸效应 总被引:1,自引:0,他引:1
研究了由水相Ti^3+制备纳米极Ti^O2微胶粒的光化反应机理及反应动力学,给出反应速率方程。讨论了TiO2微胶粒的量子尺寸效应,经电镜测试TiO2粒子的直径为15-25nm。反应过程中由气相色谱仪监测生成物H2。 相似文献
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氯酚(CP)化合物被广泛应用于木材防腐、金属防锈及杀虫剂等,因其毒性大、难降解,对环境造成严重污染[1,2]。目前用于CP的光催化降解的TiO2粉体悬浮体系,催化剂不易回收利用。本文采用Sol Gel法制备的负载型TiO2纳米粒子膜作为光催化剂,对4 CP进行了降解实验研究。同时应用XRD法表征了不同实验条件下薄膜中TiO2的晶相结构和粒度,考察了不同层数TiO2膜的光催化活性,并对4 CP的降解条件及反应动力学特征进行了探讨。1 实验部分1.1 玻璃负载TiO2膜的制备与表征[3-5]按照钛酸四丁酯∶无水乙醇∶水=3∶12∶… 相似文献
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渣油中沥青质分子颗粒尺寸及其胶粒模型研究 总被引:4,自引:0,他引:4
分别以苯和硝基苯为溶剂测定了大庆、胜利、孤岛和辽河减压渣油沥青质、胶质和芳香分的分子量;依据球形分子模型计算了这些物质的分子尺寸;构筑了渣油中沥青质胶粒(胶团)模型,并依此计算了渣油中沥青质胶粒尺寸。结果表明,以硝基苯为溶剂所测沥青质分子量更能反应沥青质化学结构的实质;就原始沥青质来说,以苯为溶剂测得的沥青质分子直径为3.8 nm~5.0 nm,以氯代苯为溶剂测得的分子直径为3.2 nm~3.7 nm,以硝基苯为溶剂测得的分子直径为2.8 nm~3.2 nm;辽河、胜利与大庆减压渣油中沥青质的胶粒直径为10.0 nm~11.0 nm,孤岛减压渣油中沥青质的胶粒直径为9.0 nm~10.0 nm。 相似文献
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Interactions between monolayers of trilaurylamine (TLA) and various water-soluble corrosion, hydrate and scale inhibitors, as well as acetic acid and FeCl2, have been studied by means of the Langmuir technique, The water-soluble compounds were present in the subphase before TLA was spread. Their influence on the monolayer properties were measured by means of surface pressure-area ( k-A) isotherms and constant surface pressure-area relaxation measurements. All the added water soluble species gave rise to monolayer expansion. The monolayer expansion observed for TLA at pH 1, increased when FeCl2 was added to the subphase at the same pH. Polyethyleneglycols with molecular weight higher than 200 destabilized totally the TLA-monolayer, probably due to bending and folding into multilayers. Monolayer expansion and film instability increased with increased acetic acid concentrations. The destabilization mechanism in this case was most likely due to a combination of nucleation and dissolution of film components into the subphase. The corrosion inhibitor Dyno KI 384 had a higher surface activity than TLA. Hence the monolayer 相似文献
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《中国化学快报》2020,31(4):1039-1043
Ti3C2Tx, a most studied member of MXene family, shows promise as a candidate electrode for pseudocapacitor due to its electronic conductivity and hydrophilic surface. However, the unsatisfactory yield of Ti3C2Tx few-layer flakes significantly restricted it in real applications. Here, we proposed a simple solution to boost the yield of Ti3C2Tx few-layer flakes by decreasing precursor size. When using the small 500 mesh Ti3AlC2 powders as raw material, high yield of 65% was successfully achieved. Moreover, the as-received small flakes also exhibit an enhanced pseudocapacior performance owing to their excellent electrical conductivity, expanded interlayer space and more O content on the surface. This work not only sheds light on the cost effective mass production of Ti3C2Tx few-layer flakes, but also provides an efficient solution for the design of MXene electrodes with high pseudocapacior performance. 相似文献
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《Colloids and surfaces. A, Physicochemical and engineering aspects》2003,220(1-3):69-81
Two series of pyrocarbon/fumed silica (CS) samples at different carbon concentrations CC=0.5–64 wt.% (first series, CSI) and 2.6–53 wt.% (second series, CSII) synthesised by means of pyrolysis of CH2Cl2 at fumed silica substrate (SBET=297 (CSI) and 232 (CSII) m2 g−1) under slightly different conditions were studied by using TEM, FTIR-PAS, DTG, and nitrogen adsorption–desorption methods. On methylene chloride carbonisation, disordered carbon deposits can form mainly in the inter-particle volume of secondary particles (aggregates of primary particles and agglomerates of aggregates) covering the surfaces of primary silica particles; therefore, marked reduction of the pore (gaps between primary particles) volume and the specific surface area is observed with increasing CC. Estimation of distributions of the pore fSCD(Rp) and particle f(a) sizes using a self-consistent method with binary regularisation with respect to both fSCD(Rp) and f(a) shows that the average size of particles increases (silica particles are covered by pyrocarbon) and individual pyrocarbon particles (up to 50 nm according to TEM) also appear. Structural parameters of carbosils are characterised by nonlinear changes with increasing carbonisation time. Surface functionalities on CS samples correspond to aromatic and twinned CC bonds with contribution of oxygen-containing groups. 相似文献
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Our improved Horvath-Kawazoe (H-K) equations (by considering the isotherm nonlinearity) for three pore geometries are first summarized. These equations apply to adsorption in microporous materials at subcritical temperatures. From a known isotherm at a given temperature, these equations are used to predict isotherms of the same adsorbate molecules at other temperatures, and also to predict isotherms for other adsorbate molecules at the same (or any subcritical) temperature. A reasonable agreement is obtained between predictions and experimental data. Since the H-K formulation only involves dispersion forces, it underpredicts for gas-solid systems in which other forces also exist. The N2-zeolite system is one of these systems. 相似文献
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Polyacrylamide nanoparticles of different size (<100 nm) were prepared in reverse micelles under various dynamic conditions of micellar systems. The nanoparticles were always larger than the aqueous core in which they were formed; however, the size of the nanoparticles could be controlled if the interdroplet interaction and coalescence rate in reverse micelles were regulated. Factors such as interfacial rigidity of the droplets, size of the aqueous core, temperature, and concentrations of acrylamide (monomer) andN,N′-methylenebisacrylamide (crosslinking agent) have a profound effect on the size of nanoparticles. By adjustment of these parameters in reverse micelles, nanoparticles ranging from about 10 to more than 100 nm have been prepared. 相似文献