Preparation Of C-materials Based TiO₂Composites And Their Photocatalytic Performances

Due to its high catalytic activity, stable chemical property and excellent quantumeffect, TiO2has been well applied as one of photocatalytic materials in Sewage treatmentand air purification. Nowday, as the environmental pollution becomes more and moreserious, the researches overcoming the defects of TiO2to improve its catalytic performanceis significantly important. In this paper, ultrasonic-assisted sol-gel and surfactant-assistedhydrothermal methods were proposed to synthesize TiO2/activated carbon fiber (ACF) andTiO2/reduced graphene oxide (RGO) composites, respectly. Their structures, morphologiesand the interaction with the photocatalytic performances were investigated. The details areas follows:1. TiO2/ACF composites were prepared by ultrasonic-assisted sol-gel approach usingTi(OC4H9)4as Ti resource and CH3COCH2COCH3as chelating agent. The structures andmorphologies of TiO2/ACF composites were characterized with X-ray diffraction (XRD),N2adsorption-desorption measurement (BET) and Scanning electron microscope (SEM),indicating that ultrasonic treatment was helpful for the combination of TiO2and ACF. TheTiO2/ACF composite obtained by ultrasonic treatment for30min in the controlledtemperature of45℃showed a perfect crystal structure of TiO2on the surface of ACF.Moreover, TiO2deposited between the gaps of ACFs was significantly reduced. Therefore,the related TiO2/ACF composite exhibited an excellent photocatalytic performance.2. TiO2/RGO composites were synthesized using the cetyl trimethyl ammoniumbromide (CTAB) assisted hydrothermal process. The structures and morphologies ofTiO2/RGO composites were characterized with XRD, SEM, transmission electronmicroscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopyand X-ray photoelectron spectroscopy (XPS). It can be demonstated that the addition ofCTAB could effectively improve the structure and morphology of TiO2/RGOnanocomposite, which consisted of TiO2nanowires in-situ grown on the smooth surface ofRGO. The TiO2nanowires were longer even to be nanowire arrays as the content of TiO2rised. The photocatalytic activity of TiO2/RGO composite with the optimal TiO2: grapheneoxide (GO) mass ratio of0.6was shown a significant improvement.3. Based on the research of the optimal mass ratio of TiO2:GO, TiO2/RGOnanocomposites were fabricated by the modified hydrothermal method with the effect ofsodium dodecyl benzene sulfonate (SDBS), Triton X-100and CTAB. The structures and morphologies of TiO2/ACF composites were characterized with XRD, FTIR, BET, SEM,TEM, Raman spectroscopy, XPS and UV-vis spectroscopy, suggesting that the addition ofsurfactants was effective to the increased surface area of TiO2/RGO nanocomposites andremain the layered structure of RGO. TiO2in the TiO2/RGO nanocomposites prepared withSDBS、Triton X-100and CTAB as surfactant exhibited the morphologies of nanoparticles,nanowires and nanowire arrays on the surface of RGO, respectively. Therefore, themechanism was quite different between diverse types of surfactants and precursor ofTiO2/RGO nanocomposite. Furthermore, CTAB was outstanding to improve thephotocatalytic performance of TiO2/RGO nanocomposite.