Preparation And Photocatalytic Activity Of TiO₂ Nanotubes Sensitized By Porphyrin

With the rapid development of the clothing industry in China,there is an increasing problem about the varies dyes and its amount.And it has become one of the key sources of the wastewater pollution.Methylene blue（MB）as dyeing wastewater in one of the typical organic pollutants have been regarded as an important target of sewage treatment.This paper against the reality of this serious pollution problem,choosing the most promising development of ervironmental-friendly materials nano-photocatalytic TiO₂ nanotube which was co-sensitized by rGO and *TCPP as a degradation of methylene blue to carry out photocatalytic degradation.Then it can deal with the actual printing and dyeing wastewater problem.What’s more,it can also provide an efficient and economically feasible way.This project will further enforce practical textile printing and dyeing wastewater treatment of organic pollutants,it can also provide scientific theoretical basis and a highly efficient wastewater treatment method to build green and easy implement way.This work will respond to the zhejiang province "five water co-work" goals and strategic layout.Thus,it has the very vital significance.The main research content of the project as following:1.TiO₂ nanotubes were successfully prepared by hydrothermal treatment through P25.The tube-like nanostructures were made up of particles with 10-to 15-nm diameters.Its tube structure is even and smooth.Then the TiO₂ nanotubes sensitized by H₂ TCPP,CuTCPP,FeTCPP,then different catalysts were obtained.The physycal and chemical structure of samples were characterized by different methods,including transmission electron microscopy（TEM）,energy-dispersive spectroscopy（EDS）,powder X-ray diffractometry（XRD）,X-ray photoelectron spectroscopy（XPS）,photoluminescence（PL）and electron paramagnetic resonance（EPR）.2.Then,GO was prepared through a modified Hummers’ method.The sample was labeled as GO.RGO-TNT was successfully prepared by a modified hydrothermal treatment method.Then rGO-TNT was sensitized by CuTCPP.This process yielded rGO-TNT coupled with different loadings of CuTCPP,it was labeled as CuTCPP/rGO-TNT.The physycal and chemicalstructure of samples were characterized by different methods,including transmission electron microscopy（TEM）,energy-dispersive spectroscopy（EDS）,powder X-ray diffractometry（XRD）,X-ray photoelectron spectroscopy（XPS）,photoluminescence（PL）and electron paramagnetic resonance（EPR）.3.Photocatalytic measurements of the samples were evaluated based on the degradation rate of MB（10 mg/L）under visible light irradiation from a halogen lamp with a 390-nm cut-off filter.The analysis of the degradation and absorption for MB in water was then performed by measuring its absorption at 663 nm with a UV-vis spectrophotometer.Additionally,all of the samples were separated with centrifugal filtration at 104 rpm and the precipitate was reused for the next cycle to test its chemical stability and second-time usability.We successfully prepared TNTs which are co-sensitized by CuTCPP,and it was carefully spreaded over rGO sheets.Their co-photocatalytic behavior is evaluated by different methods.In the catalyst,graphene works as the adsorbent,the CuTCPP plays a critical role in capturing photons.Then it can expand the absorption wavelength to the visible light region when dealing with organic pollutants.In addition,a deeper insight into the co-photocatalytic mechanism of CuTCPP/rGO-TNT nanocomposites is presented.Thus,this work provides new opportunities for rGO-TNT nanosized composites modified by CuTCPP semiconductor nanocomposite to probe visible light-assisted improvement of stable and highly efficient photocatalysts.Additionally,these materials are expected to be developed as chemically stable materials to address various environmental and energy-related issues.The visible light photocatalysis mechanism of the dye-sensitized TiO₂ nanotube was further discussed.And the factors that influenced the effect of TiO₂ nanotube catalyst was also acquired.The effect of The degradation and absorption experimental results confirmed that it was significantly beneficial to the photodegradation of MB solution in the presence of porphyrin-TiO₂ nanotube under visible light,which could provide a potential approach for the energy saving application and wastewater treatment.