表面活性剂模板法构筑有序介孔三氧化钨及其光电化学水氧化性能  

Architecture of Ordered Mesoporous Tungsten Oxide Using Surfactant as Templates for Photoelectrochemical Water Oxidation

作　　者：李东[1,2] 吴发超 李瑞 高彩云 LI Dong;WU Fachao;LI Rui;GAO Caiyun(School of Material Science and Engineering,North Minzu University,Yinchuan 750021,China;International Scientific&Technological Cooperation Base of Industrial Waste Recycling and Advanced Materials,Yinchuan 750021,China;Chemical Science and Engineering College,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学材料科学与工程学院,银川750021 [2]工业废弃物循环利用及先进材料“国际合作基地”,银川750021 [3]北方民族大学化学与化学工程学院,银川750021

出　　处：《材料导报》2022年第13期58-63,共6页Materials Reports

基　　金：宁夏自然科学基金(2021AAC03170,2019AAC03112);北方民族大学校级重点科研项目(2019KJ02)。

摘　　要：以三嵌段共聚物F127为模板剂,通过钨粉过氧化钨酸、溶剂挥发诱导自组装法制备了有序介孔三氧化钨(m-WO_(3)),并采用X射线衍射(XRD)、Brunauer-emmett-teller(BET)、透射电镜(TEM)、傅里叶红外光谱(FTIR)、拉曼光谱(Raman)、场发射扫描电子显微镜(FESEM)等方法对其结构、孔隙率、形貌、光谱性质及组成进行表征。结果表明,m-WO_(3)具有二维六方P6mm对称结构;与无孔WO_(3)(5 m^(2)/g)相比,m-WO_(3)的比表面积增加了20倍(105 m^(2)/g)且孔径分布更均一(6.7 nm)。XRD结果表明,m-WO_(3)的结晶度均高于同条件下的WO_(3)。光电化学(PEC)测试结果表明,400℃下的m-WO_(3)电极在1.0 V vs.Ag/AgCl偏压作用下,产生了0.88 mA/cm^(2)的饱和光电流,约是同条件下WO_(3)电极(0.27 mA/cm^(2))的3.3倍。这主要是因为m-WO_(3)的比表面积较大,有效地提高了光生电子和空穴的分离效率,进而显著地增强了m-WO_(3)的PEC活性。此外,m-WO_(3)具有比无孔WO_(3)更稳定的光电催化活性。虽然高温煅烧导致m-WO_(3)的介孔孔道部分坍塌,但是其仍具有较大的比表面积,很好地保持了优越的PEC催化活性,解决了介孔材料结晶度和比表面积之间存在的对立矛盾。Ordered mesoporous WO_(3)(m-WO_(3))was prepared from peroxotungstic acid combined with evaporation-induced self-assembly technique,in which F127,a triblock copolymer,was used as template.The mesostructure,morphologies,porosity,spectral properties and composition of m-WO_(3) were characterized by X-ray diffraction spectrometer(XRD),brunauer-emmett-teller(BET),transmission electron microscope(TEM),fourier transform infrared spectra(FTIR),Raman microspectroscopic(Raman)and field-emission scanning electron microscope(FESEM).The results confirm that m-WO_(3) exhibites 2D hexagonal P6mm symmetric structure with the specific surface area of 105 m^(2)/g,which is 21 times larger than that of non-porous WO_(3)(5 m^(2)/g),while the pore size distribution was more uniform(6.7 nm).XRD results show that the crystallinity of m-WO_(3) samples is higher than that of WO_(3) samples under the same calcination condition.The photoelectrochemical(PEC)results indicate that m-WO_(3) calcined at 400℃generates the photoanodic current density of 0.88 mA/cm^(2) at 1.0 V versus Ag/AgCl,which is 3.3 times higher than that of WO_(3) electrode(0.27 mA/cm^(2)).It is attributed to the large surface area of m-WO_(3),which can promote the separation of photogenerated electrons and holes efficiently,and thus significantly enhance the activity of m-WO_(3).In addition,m-WO_(3) exhibites more steady photocatalytic activity than non-porous WO_(3).m-WO_(3) still maintains superior catalytic activity due to its large specific surface area,despite the partial collapse of the mesostructure at high temperature.It was successful to solve the contradiction between crystallinity and specific surface area of mesoporous materials.

关 键 词：介孔结构 软模板 三氧化钨 光电化学 水氧化 

分 类 号：O643[理学—物理化学] TB383[理学—化学]