N-CQDs修饰介孔TiO2/RGO异构体的构建及光催化性能研究

Study on the structure and photocatalytic properties of N-CQDs modified mesoporous TiO2/RGO isomers

以柠檬酸三铵为前驱体,构建了系列N-CQDs(N掺杂碳量子点)修饰介孔TiO2/RGO(还原氧化石墨烯)异构体,并通过XRD、TEM、BET、BJH、XPS、PL、UV-Vis等测试手段系统表征其样品的微观结构以及谱学性能,通过使用模拟太阳光为光源测试其光催化性能。实验可知,所构建系列样品均为锐钛矿相TiO2晶体结构,且显著形成了H2型介孔结构,均属于langmuir Ⅳ型孔径结构;柠檬酸三铵的引入以及RGO的异构化逐步地增加介孔TiO2光催化体系比表面积,体系比表面积最高可达331.6 m^2/g;N-CQDs的修饰以及RGO的异构化,使介孔TiO2光催化体系光生电子效率逐步地提升,同时体系光谱响应范围逐步地拓宽;所构建介孔TiO2异构体均具有较强的可见光光催化性能,其中样品N-CQDs-MT/RGO-1.8的光催化活性最强,在模拟太阳光照射下,对甲基橙的降解率在10 min内可达到90%左右,1 h的降解率可达到99%。

A series of N-CQDs(N-doped carbon quantum dots) modified mesoporous TiO2/RGO(reduced graphene oxide) isomers were constructed with triammonium citrate as the precursor. The microstructure and spectral properties of the samples were systematically characterized by XRD, TEM, BET, BJH, XPS, PL, UV-Vis and other test methods. The photocatalytic properties were tested with simulated sunlight as the light source. It can be seen from the experiment that the series of samples constructed were all crystal structure of anatase phase TiO2, and the H2-type mesoporous structure was significantly formed, which all belonged to pore size structure of Langmuir Ⅳ type. The introduction of triammonium citrate and the isomerization of RGO gradually increased the specific surface area of the mesoporous TiO2 photocatalytic system, and the specific surface area of the system was up to 331.6 m^2/g. With the modification of N-CQDs and the isomerization of RGO, the photoelectron efficiency of mesoporous TiO2 photocatalytic system was gradually improved, and the spectral response range of the system was gradually broadened. The constructed mesoporous TiO2 isomers had strong visible photocatalytic performance, and the photocatalytic activity of sample N-CQDs-MT/RGO-1.8 was the strongest. Under the irradiation of simulated sunlight, the degradation rate of methyl orange could reach about 90% within 10 min and 99% within 1 h.