石墨烯-TiO_2光催化剂复合板制备及其对五氯酚的催化降解

Generation of Graphene-titanium Dioxide Nanotubes Catalytic Board and Its Photocatalysis Capability to Degrade Pentachlorophenol

针对基于石墨烯-TiO_2的光催化剂多为粉末状,用于处理实际淋洗液时难以有效回收这一问题,研究以氧化石墨烯和粉末TiO_2为前期物使用水热法结合类溶胶凝胶涂布法制备出了可重复使用的石墨烯-TiO_2纳米管复合板,复合板的宏观形貌均一,催化剂在板的大部分区域上以层数较少的形式负载.应用制备的复合板对土壤淋洗液体系中的五氯酚(pentachlorophenol,PCP)进行光催化降解,在太阳光照下可在30 min内完全去除污染物,比无催化剂条件下的降解速率提高5倍以上;以氙灯作为模拟太阳光源,降解速率提高10倍.复合板经长时间浸泡和重复使用后,光催化活性无明显下降,具有长期使用的潜力.复合板的制备解决了催化剂的固定化问题,有利于分离回收等后续处理.

Considering that the photocatalysts used in research are generally in powder form,which increase the difficulty of efficient recycle in practice,this research focused on the generation of graphene-titanium dioxide nanotubes catalytic board. Graphene oxide and TiO_2 powder were used as precursors; the sol-gel like coating method along with hydrothermal method was adopted to synthesize the catalytic board. The generated board presented a uniform surface morphology and in its most regions,the catalyst was loaded in the form of a single layer or few layers. During the photodegradation process in the eluent system,under solar irradiation,the removal ratio of the pentachlorophenol（ PCP） could reach almost 100% within 30 min,the degradation rate was increased by more than 5 times compared with the eluent without addition of photocatalyst; while under xenon lamp,the degradation rate was increased by 10 times.After long-time soaking and repeated use,the photocatalytic activity of the board did not decrease obviously,which is suitable for longterm use. The application of the board could solve the problem of immobilized catalyst and enable catalyst recycling in subsequence processing.