纳米石墨微片/TiO_2复合材料的制备及其光催化性能

Preparation and Photocatalytic Property of Graphite Nanosheets/TiO_2 Composites

基于石墨烯与TiO_2协同作用可提高TiO_2光催化效率,以纳米石墨微片替代石墨烯,采用水热法原位制备纳米石墨微片/TiO_2复合材料(GN/TiO_2),主要研究了乙酸加入量、纳米石墨微片加入量对复合材料物相形貌的影响,并以亚甲基蓝为目标污染物考察了GN/TiO_2的光催化性能。结果表明,TiO_2全部为锐钛矿晶型。TiO_2纳米颗粒附着在片状的纳米石墨微片表面。改变乙酸的加入量可控制钛酸丁酯的水解进而保证复合材料内二者分散均匀性,乙酸加入量为20m L时可充分抑制钛酸丁酯水解,获得稳定前驱体溶液。改变纳米石墨微片的加入量,影响TiO_2的分散性,增加纳米石墨微片加入量到50%(质量分数)时,TiO_2均匀负载在纳米石墨微片表面。采用优化参数(乙酸20 m L、纳米石墨微片50%,质量分数)制备了复合材料,复合材料在120 min对亚甲基蓝脱色率达到93%以上。

The photocatalytic efficiency of TiO_2 can be improved based on synergistic effect between TiO_2 and graphene. Graphite nanosheets were used. Graphite nanosheets/titanium dioxide(GN/TiO_2) material was synthesized by in situ hydro-thermal method. The effects of the dosage of acid, and graphite nanosheets addition on the phase morphology of composite materials have been investigated. GN/TiO_2 photocatalytic properties were investigated with methylene blue as the goal pollutant. The results show that the main phase of as-prepared products is antase TiO_2 and the nanoparticles attached on the surface of the flake Graphite nanosheets. The hydrolysis of Ti(OC_4H_9)_4 can be inhibited by addition of HAc, which ensure the dispersion of graphite nanosheet and TiO_2. When the dosage of HAc is 20 mL, the hydrolysis can be sufficiently inhibited and stable polymeric precursor solution is obtained. The dosage of graphite nanosheets influences the dispersibility of composite. When the addition of graphite nanosheets is 50 wt%, TiO_2 is uniformly dispersed on the graphite nanosheets surface. The synthesized GN/TiO_2 has decolorization rate of more than 93% in 120 min using methylene blue as the goal pollutant.