CNT/Fe-Ni-TiO2/ZnO多孔复合膜的组装及其制氢性能

Fabrication of CNT/Fe-Ni-TiO_2/ZnO Porous Composites Film and Performance in Hydrogen Production

以聚苯乙烯(PS)微球为模板,通过溶胶凝胶法在导电玻璃(FTO)和镍片上负载掺杂铁、镍的复合纳米TiO_2-ZnO有序多孔膜。以多孔膜中的铁、镍为催化剂,通过化学气相沉积法(CVD)原位生长碳纳米管(CNT),得到CNT/Fe-Ni-TiO_2/ZnO/FTO(Ni)三维交互多孔复合膜。场发射扫描电镜观察发现,当TiO_2-ZnO前驱体中TiO_2与ZnO的体积比为3∶2时,复合膜中孔排布的规整性较好。采用X射线衍射仪、紫外-可见吸收光谱、电化学阻抗谱分析和光催化辅助电解水制氢等仪器和手段考察多孔复合膜的结构与性能,结果表明:孔结构的规整性、TiO_2-ZnO异质结和CNT与复合膜形成的三维网络结构有利于提高光生电子-空穴对的分离效率和复合膜材料的光催化活性。

The development and utilization of hydrogen could be an effective way to solve the problem of energy crisis and environmental pollution.In order to improve the efficiency of hydrogen production of the industrial alkaline water electrolysis,it is worth considering the combination of water electrolysis with photo-catalytic decomposition of water for producing hydrogen.Water electrolysis assisted by photo-catalysis for hydrogen production has been studied,while the key technology is the anode modified by photo-catalyst.It’s well known that TiO 2 has the defects of low utilization of visible light and low quantum yield,thus it is necessary to improve photo-catalytic properties of TiO 2 by metal ion doping,semiconductor recombination,noble metal deposition and structured regular nanostructures.Meanwhile,carbon nanotubes(CNTs)have unique mechanical and electrical properties that can enhance the structural stability and electron transport rate of the material.And in the photo-catalytic process,CNTs have an important role in increasing the separation efficiency of photo-generated carriers.Using polystyrene microsphere as template,highly ordered TiO 2-ZnO porous composite film doped with iron and nickel were prepared on the FTO and Ni anode by sol-gel method.Using the doped iron and nickel as catalyst,after growing CNTs by in-situ chemical vapor deposition(CVD)on Fe-Ni-TiO 2/ZnO,CNT/Fe-Ni-TiO 2/FTO(Ni)of porous composite film with three dimensional porous structure was fabricated.The analysis of scanning electron microscopy(SEM)indicated that the composite film present highly ordered porous construction when V(TiO 2)∶V(ZnO)in the precursor of TiO 2-ZnO was 3∶2.The structure and properties of composite film were characterized by X-ray diffraction(XRD),UV-vis absorption,electro-chemical-impedance spectroscopy(EIS),and water electrolysis assisted by photo-catalysis(WEAP).Compared with nickel anode,the hydrogen production activity of CNTs/TiO 2-ZnO porous membrane modified nickel electrode was increased by 307.4%.The experimental results showed that the separation effect of electron-hole pair and photo-catalytic activity of the composite film would be promoted by the ordered porous structures,TiO 2-ZnO hetero-junctions and the three dimensional porous structure.