石墨烯/Ni/TiO_2/CNTs复合物的制备及其光催化性能

Synthesis of Graphene/Ni/TiO_2/CNTs Composites and Photocatalytic Activities

首先通过溶剂热法,在石墨烯表面负载掺杂镍的纳米二氧化钛膜,制备石墨烯/Ni/TiO2复合材料;然后以掺杂的镍为催化剂,采用化学气相沉积法,原位生长碳纳米管(CNTs),得到石墨烯/Ni/TiO2/CNTs复合材料。通过XRD、SEM、TEM、拉曼等方法对制备样品的晶型、微观形貌等进行了表征,考察了样品在紫外光及可见光下对甲基橙的光催化降解性能。结果表明:石墨烯和CNTs的加入使得Ni/TiO2、石墨烯/Ni/TiO2、石墨烯/Ni/TiO2/CNTs复合物的光催化活性依次提高,并且石墨烯/Ni/TiO2/CNTs复合物中石墨烯含量越多时,所得复合物的光催化降解性能越好。石墨烯含量最大的石墨烯/Ni/TiO2/CNTs样品,在紫外光下对甲基橙的降解率达到98%,在可见光下的光催化降解效率比掺镍TiO2提高了3.5倍。

TiO2 nanoparticals doped with nickel were coated on graphene by solvo-thermal method. Then the CNTs were grown by in-situ chemical vapor deposition using nickel as catalyst. Finally, the graphene/Ni/TiO2/CNTs nanocomposites was obtained. The prepared graphene/Ni/TiO2/CNTs nanocomposite photocatalyst was characterized by X-ray diffraction, field emission scanning electron microscope, transmission electron microscope and Raman spectra. The photocatalytic activities of the samples were investigated by the photocatalytic degradation of methyl orange under UV and visible light. The results indicated that the photocatalytic activities increased from Ni/TiO2, graphene/Ni/TiO2, to graphene/Ni/TiO2/CNTs by the addition of graphene and CNTs. And the photocatalytic activities of graphene/Ni/TiO2/CNTs increased with the graphene amount increase. For the sample graphene/ Ni/TiO2/CNTs with the highest graphene content, its photocatalytic degradation of MO under UV irradiation reached 98%, and its photocatalytic degradation of MO under visible light irradiation was 3.5 fold higher than that of sample Ni/TiO2.