石墨烯杂化钛酸管复合光催化剂的制备与表征

Graphene Modified Titanate Nanotubes Composite Photocatalyst:Preparation and Characterization

以化学法还原的石墨烯和纳米TiO2为原料,采用水热法制备出一系列具有良好可见光活性的石墨烯-钛酸管复合光催化剂,并研究石墨烯含量和水热温度对其光催化性能的影响.结果表明:当石墨烯质量分数为5%时,复合光催化剂的催化活性最佳;采用较低水热温度制备出的复合光催化剂具有更大的比表面积和更优异的催化性能,其比表面积为一般石墨烯-TiO2复合光催化剂的10倍;在可见光照射条件下,其降解罗丹明-B的速率常数可达8.76×10-2 min-1,远高于文献报道的TiO2类光催化剂降解的速率常数;其可见光活性来源于石墨烯的敏化作用.

A series of composite photocatalysts were prepared under hydrothermal conditions by using chemical reduced graphene and nanoscale TiO2 as raw materials. The influences of graphene content and hydrothermal temperature were studied. The 5% （mass fraction） graphene contented photocatalyst posses- ses the best photoactivity. The catalyst prepared at lower hydrothermal temperature has a larger BET sur- face area and better catalytic performance. The BET surface area of the prepared composite photocatalyst is 10 times larger than that of previously reported graphene TiO2 photocatalysts. The rate constant of de- grading Rhodamine-B reaches 8. 76 × 10-2 min-1 , which is at least 5 times faster than that of reported TiO2-based photocatalysts. Based on the results of UV-vis diffuse reflection spectra and XPS, the visible- light responses of the prepared photocatalysts are originated from the sensitization of graphene.