悬浮纳米TiO2自然光助催化降解偶氮染料酸性大红GR

以自然光为光源,悬浮纳米TiO2为光降解催化剂,研究了溶液pH值、酸性大红GR初始质量浓度、TiO2质量浓度、H2O2的质量浓度及光照时间对偶氮染料酸性大红GR降解的影响.结果表明悬浮纳米TiO2自然光光助催化降解酸性大红GR的适宜条件为:溶液pH值6.5,酸性大红GR初始质量浓度40 mg/L,TiO2质量浓度1.2 g/L,H2O2质量浓度5 g/L,光照时间为120 min.在此条件下,酸性大红GR降解率达75%以上,且降解反应符合一级反应动力学,其动力学常数为0.011 min-1.

太阳能TiO_2膜对活性黄棕K-GR的光催化脱色研究

采用自制实验装置,研究了太阳光照射玻璃弹簧负载TiO2膜对活性黄棕K-GR脱色的影响。结果表明,在水溶液浓度15 mg.L-1、pH 3、流速20 mL.s-1、太阳光强度1 200μW.cm-2以上,反应时间3 h时,脱色率为95%以上。

Improving the photocatalytic performance of TiO2 via hybridizing with graphene

In this paper an improvement in the photocatalytic performance of TiO2 was carried out via hybridizing with graphene.Graphene-TiO2（GR-TiO2/nanocomposites with different weight addition ratios of graphene oxide（GO）have been prepared via a facile microwave irradiation of GO and tetrabutyl titanate in isopropyl alcohol.Raman spectroscopy（RS）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,UV–visible spectroscopy（UV–vis）,Fourier transform infrared spectra（FTIR）,energy dispersive X-ray spectroscopy（EDX）and photoluminescence spectra（PL）are employed to determine the properties of the samples.Microwave irradiation can heat the reactant to a higher temperature in a short time,simultaneously GO is reduced to graphene and TiO2 nanoparticles grown on the surface of GR.GR-TiO2 nanocomposites synthesized via this approach have efficient electron conductivity in GR,resulting in a reduced electron–hole recombination rate.Among the synthesized nanocomposites,GT-8wt% exhibited the best photocatalytic activity toward photocatalytic degradation of MB.Our current work provides a new insight for the fabrication of GR-TiO2 nanocomposites within a short reaction time and also explains the mechanism of photocatalysis employing radical and hole scavengers.