基于静电纺丝法制备钛、钒基复合纳米纤维及其可见光下催化性能研究

发布时间：2019-02-27 15:37

【摘要】：以聚乙烯吡咯烷酮(PVP)为模板剂,乙醇(C_2H_5OH)为溶剂,钛酸正丁酯为钛源,氧化石墨烯(GO)为改性剂,通过静电纺丝法和焙烧处理,得到连续纳米结构的还原氧化石墨烯/氧化钛(RGO/Ti O_2,RT)复合纤维。所制备的RT复合纤维具有直径小,表面的羟基自由基浓度高和光吸收性能强的特点,在亚甲基蓝(MB)的降解中RT比纯Ti O_2和催化剂P25有更高的降解效率;并且当控制煅烧温度为450℃时,对MB的降解效果最佳。以PVP为模板剂,二甲基甲酰胺(DMF)和乙醇为溶剂,乙酰丙酮钒为钒源,导电玻璃(FTO)为载体,通过静电纺丝法制备RGO/V_2O_5/FTO(RVF)复合光电极。研究发现经过500℃控温焙烧后,PVP完全分解,附着于FTO上的RGO/V_2O_5(RV)呈纳米棒状结构;RGO的引入有效降低了光生电子-空穴的复合率,提高催化剂表面的羟基自由基浓度,使得复合光电极的催化性能明显高于纯V_2O_5/FTO(VF);另外,RGO浓度影响RVF光电催化性能,发现GO的加入量为5%时,催化效率最高。采用相同的制备工艺,以三水硝酸铜(Cu(NO_3)_2·3H_2O)为铜源,代替GO,通过静电纺丝法制备Cu O/V_2O_5/FTO复合光电极(CVF)。经过500℃控温焙烧后,材料仍保持纤维形貌,直径分布在150-200nm之间;Cu O与V_2O_5能有效复合,构建p-n异质结,提高光生电子和空穴的分离效率,使其光电催化活性比纯V_2O_5/FTO(VF)有明显提高;另外,Cu O与V_2O_5的比例严重影响其光电催化性,当n(Cu):n(V)=1:1时,CVF对MB降解效率最高,达到96%,并且具有良好的重复使用性能。采用相同的制备工艺,以钨酸铵(H_(40)N_(10)W_(12)·x H_2O)为钨源,制备了WO_3/V_2O_5/FTO光电极(WVF),发现其光电催化性能比纯V_2O_5/FTO电极(VF)强,这归功于WO_3与V_2O_5间异质结形成,加速光生电子-空穴对的分离;当n(V)/n(W)为1:2时催化率最高,对MB的降解率达95%;并且具有良好的重复使用性能。
[Abstract]:Polyvinyl pyrrolidone (PVP) was used as template, ethanol (C_2H_5OH) was used as solvent, n-butyl titanate was used as titanium source, graphene oxide (GO) was used as modifier, electrospinning and roasting were carried out. Continuous nanostructured reduced graphene / titanium oxide (RGO/Ti O _ 2O _ 2, RT) composite fibers were prepared. The prepared RT composite fiber has the characteristics of small diameter, high hydroxyl radical concentration on the surface and strong optical absorption. The degradation efficiency of RT is higher than that of pure Ti O _ (2) and catalyst P _ (25) in the degradation of methylene blue (MB). When the calcination temperature is 450 鈩，

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