微孔纳米三氧化钨的制备、表征及掺稀土后光催化活性研究

将钨酸钠用阳离子树脂交换得钨酸溶胶、凝胶,发现钨酸凝胶是WO3.2HO2结晶相与无定形态的混合物,对其进行重复超声洗涤、离心,能将结晶相分离,制得的三氧化钨纳米晶粒逐渐成为微孔薄片,随离心时间延长,其晶粒比表面积逐渐增大;离心7 h后样品比表面积增加近2倍而显示更高光催化活性;在离心7 h微孔H0.10WO3.1.06H2O中掺入0.5%稀土氧化物(Ce2O3,La2O3,Pr2O3),其活性Ce3+>Pr3+>La3+,并探讨其影响机制。

超声空化、离心钨酸凝胶对产物纳米三氧化钨物化性能的影响及其光催化活性

钨酸钠经阳离子树脂交换制备钨酸溶胶、凝胶,发现对其进行重复超声波洗涤、离心,能够制备出具有微孔高比表面积纳米三氧化钨薄片。分别研究超声波洗涤、传统洗涤、离心处理对三氧化钨结晶结构、晶粒及形貌的影响,并探讨其影响机理及光催化降解气相有机污染物活性。

Preparation and Characterization of Microporous Nano-Tungsten Trioxide and Its Photocatalytic Activity after Doping Rare Earth

Aqueous sols and gels of tungstic acid were prepared from Na2WO4 with protonated cation-exchange resin. Nano-tungsten oxide of a microporous lamella was synthesized by means of washing of WO3· 2H2O with distilled water under ultrasonic wave agitation and centrifuging repeatedly, and the specific surface area tended to increase gradually with washing and centrifuging. The sample of centrifuged 7 h has more than 2 times highs specific surface area and more high photocatalytic activity . The mechanisms are also discussed.

新的六方晶钨氧化合物Na_xWO_3的制备

用热液法制备了ＮａｘＷＯ３，ｘ为０００１８～００３８０，这是一类新的六方晶钨氧化合物．斜方晶钨酸钠酸化水洗，再进行热液脱水；当钠含量≥１６０×１０－６时（质量分数），得到斜方晶ＷＯ３·１３Ｈ２Ｏ单相，当钠含量≤４０×１０－６时，得到ＷＯ３·Ｈ２Ｏ单相，当钠含量在４０×１０－６～１６０×１０－６之间则为两相混合物．斜方晶ＷＯ３·１３Ｈ２Ｏ在２９０～４２０℃脱水得到六方晶ｈＮａｘＷＯ３；继续升高温度在４２０～４５０℃恒温处理，则得到单斜晶ｍＮａｘＷＯ３．