【摘要】 采用改进化学气相沉积法(CVD)合成了MWNT-TiO2:Ni复合光催化剂,利用扫描电镜(SEM)和拉曼光谱(Ra-man)对催化剂进行表征,考察催化剂的光催化分解甲醇水溶液制氢的活性,并对其光催化机理进行了初步分析.研究表明,多壁碳纳米管(MWNTs)原位生长能显著提高二氧化钛(TiO2)的光催化制氢能力.当MWNTs的含量为4.4%时,催化剂的紫外光催化活性达到最大,光量子效率为4.8%.其反应机理解释为MWNTs的"氢溢流"效应,促进光生电子从TiO2向MWNTs转移,降低光生电子-空穴对的快速复合;同时,MWNTs生长有利于提高复合光催化剂的光吸收能力.更多还原

【Abstract】 Multi-walled carbon nanotube,TiO2 and Ni(MWNT-TiO2:Ni) composite catalysts were prepared by a modified chemical vapor deposition.The nanoscaled composite materials with different MWNT contents were characterized by scanning electron microscopy(SEM) and Raman spectroscopy.The photoactivity was evaluated by photocatalytic production of H2 from aqueous methanol solution.The presence of MWNTs greatly increases the production of H2.An optimum MWNT content was found for 4.4% by the twice-growth MWNTs and corresponding quantum yield was 4.8%.In addition,the mechanisms of photocatalytic reaction are proposed that the "hydrogen spillover" effect of MWNTs and subsequent reduction activation energy are dominant;whereas the enhancement of photoabsorption capability and the suppression of recombination of e-/h+ pairs by MWNTs should also be considered.更多还原