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磁性纳米TiO2/Fe3O4光催化复合材料的制备及性能 总被引:27,自引:2,他引:27
采用溶胶-凝胶法,在磁性Fe3O4表面包覆TiO2,制备了一种新型纳米TiO2/Fe3O4光催化复合材料.XRD,TEM对材料形态结构及包覆情况的分析,显示TiO2包覆在Fe3O4表面,形成平均尺寸为35~50nm的复合结构;UV-vis吸收曲线表明,复合材料对光的吸收出现红移,吸收强度增大;对染料废水光催化降解的模拟研究表明,该复合材料对活性艳红染料的脱色率达100%,是一种便于回收、可重复使用的高效光催化剂. 相似文献
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通过研究对甲苯磺酸酯空心酞菁的性质,发现该化合物在紫外光照射下可生酸,是一种光生酸剂.由于酞菁类化合物本身具有光催化氧化反应的性能,因此这类光生酸剂在光蚀刻技术中将有很好的应用潜能. 相似文献
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The nano-composites based on the burnt rice straw waste, reformed by nano-TiO2 and copper phthalocyanine (CuPc), namely, RSA-TiO2, RSA-CuPc, and RSA-TiO2-CuPc were prepared by a mechano-chemical method. The as-prepared composite systems were characterized by adopting FE-SEM, TEM, XRD, FTIR, SBET, and optical techniques. Their photo-catalytic performance in the degradation of methylene blue dye was evaluated under visible light irradiation. The co-existence of the two components in RSA, SiO2 and organic carbon, plus the inherently intimate contact between nano-TiO2 and CuPc could improve the photo-degradation of MB dye. The complete degradation of MB dye was achieved by using RSA-TiO2 (50) nano-composite and the time is taken for 50% degradation of a dye is 53 min under visible light radiation. The kinetic study revealed that photo-degradation of MB follows a pseudo-first-order reaction mechanism, where the kinetic rate constant was 0.013 min−1. 相似文献
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自行搭建了用于研究表面光催化的宽带红外和频振动光谱并可以原位紫外光激发的装置. 利用自制的结构紧凑小巧的高真空样品池,可以在10 kPa氧气氛围下经原位紫外光照除掉 射频磁控溅射制备的二氧化钛薄膜表面的有机污染物. 通过在室温下改变甲醇气压和指认吸附在薄膜表面的甲醇的和频振动光谱,发现薄膜表面有两种吸附的甲醇,分子形式吸附的甲醇(CH3OH)和解离吸附的甲醇(CH3O). 当甲醇的覆盖度由低变高时,分子形式吸附的甲醇的CH3的对称伸缩振动和费米共振峰红移了6~8 cm-1. 真空下,薄膜表面的甲氧基和表面的氢原子可以重新结合并以甲醇分子的形式脱附. 研究表明二氧化钛薄膜体系存在两个平衡:气相甲醇和表面吸附的甲醇分子之间,以及表面吸附的甲醇分子和甲氧基之间. 相似文献
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《分子催化》2012,26(2)
以钛酸丁酯为前驱体,以尿素为氮源,采用溶胶-凝胶法制备了不同N含量的TiO2光催化剂(N-TiO2).通过X-射线衍射(XRD)、紫外-可见吸收光谱(UV-Vis)、分子荧光光谱(PL)、X-射线光电子能谱(XPS)等检测手段对其结构和物理性能进行了表征.结果表明,N的掺杂能抑制锐钛矿相TiO2向金红石相的转化,能将TiO2的吸收边波长拓宽到可见光区域,能加速光生电子-空穴对的分离,提高光催化活性.在以可见光为光源进行重铬酸钾的光催化还原和苯酚的光催化氧化反应中,9%N-TiO2-500表现出了最强的光催化活性,且在光催化活性的稳定性实验中,表现出良好的光催化活性的稳定性,能多次重复使用. 相似文献
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High Photocatalytic Activity of F-Doped TiO2 Film on Glass 总被引:7,自引:0,他引:7
The photoreactivity of sol-gel (SG)-TiO2 films was enhanced significantly with addition of a small amount of trifluoroacetic acid (TFA) into the starting solution. The promoting effect was confirmed in two separate experiments of the methylsiloxane monolayer oxidation and the photocurrent measurements. The results of film characterization indicated that the absorption coefficient for ultraviolet light ( < 360 nm) increases due to film densification and the crystallinity is improved upon F doping. The improvement in the photoreactivity was ultimately attributed to the increase in the rate at which the photogenerated charge carriers reach the surface in the photostationary state. 相似文献
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钕掺杂提高TiO2光催化活性的机制 总被引:27,自引:4,他引:27
采用X射线衍射(XRD), BET吸附, X射线光电子能谱(XPS)表征了溶胶凝胶法制备的Nd掺杂TiO2光催化剂的晶体结构、表面电子结构与化学组成. 以甲基橙为有机底物, 测试Nd掺杂对光催化剂吸附性能和光催化活性的影响. 结果表明, Nd掺杂可阻碍TiO2的晶相转变, 减小光催化剂的晶粒尺寸, 比表面积增大. Nd掺杂提高光催化剂表面三价钛(TiⅢ)的含量及其对甲基橙的吸附能力是其提高TiO2光催化降解甲基橙活性的主要原因. Nd掺杂量为1.2%时, 光催化剂活性最高. 相似文献