The Preparation Of Fe³⁺ions/Pt Co-loaded Brookite TiO₂ Used For Processing Plant VOCs Decomposition Under Visible Light

Part 1.The property research of brookite TiO2 prepared by different methodsCompared to other two common crystal forms(anatase phase and rutile phase),the properties and applications on brookite TiO2 remain to be explored.In this thesis,3 kinds of different synthetical approaches were empolyed to prepare the brookite TiO2.In the first two methods,glycolic acid was used to prepare the brookite TiO2 precursor.Then the hydrothermal synthesis was performed at 160 or 200?,respectively.We used titanium(IV)bis(ammonium lactate)dihydroxide solution(TALH)in the third method as precursor and conducted the hydrothermal synthesis at 200?.The samples were named as g-160,g-200 and t-200,respectively.Then,XRD and TEM were used to analyze the components and structures of the obtained samples.Benefit for narrow band gap and suitable valuance/conduction band energy,the loaded Fe3-ions(FeOOH)can give bare brookite TiO2 visible light response capability.Afterwards,Fe3+ions were modified on the oxidation surface of brookite TiO2 site-selectively.It is proved that the modificated Fe3+ions on the oxidation site can give pure brookite TiO2 visible light responsive capability.Then the in-depth photocatalytic activity experiments were carried out under visible light with varing of Fe3+ions.Finally,g-160 was proved to be the optimal one in comparison with other two samples.And the optimal Fe3+ tions loading ratio of g-160 was determined to be 0.2 wt%according to photocatalytic capability.Part 2.A Fe3+ ions and Pt site-selective co-loaded brookite preparation and property discussionIn this section,site-selective modification and non-site-selective modification were performed on the surface of g-160 sample,respectively.From the results of photocatalytic activity experiment,it is obvious that site-selective modified samples showed improved properties in contrast to the non-site selective modified samples.Beacuse of the electron caputuring capability,the loaded Pt can promote the electron-hole pairs separation and increase the photocatalytic activity Then in the principle of site-selective modification,Pt nano-particles were modified on the reduction surface of g-160 sample.The optimal amount of Pt was confirmed to be 0.3 wt%.Finally,Fe3+ ions and Pt nanoparticles site-selective co-modified brookite TiO2 was obtained by the photodeposition method.The obtained photocatalyst showed an average 11%enhauncment of acetone decomposition rate comparing to the single Fe3+doped brookite TiO2 catalyst.Part 3.The simulative exploration of refinery volatile organic compounds(VOCs)decomposition on Fe3+/Pt co-loaded brookite TiO2 under visible lightIn this section,the Fe3+ ions and Pt nanoparticle site-selective co-modified brookite TiO2 was used to decompose the VOCs in the condition of laboratory.In the decomposition experiment,we selected n-Hexane,toluene,acetone,acetaldehyde and 2-propanol as 5 representhre refinery VOCs.The physical absorption and photocatalytic decomposition properties of as modified brookite TiO2 was conducted.In the meantime,the stability of Fe3+ions and Pt co-loaded brookite TiO2 were examined.It was demonstrated that the current visible light responsive photocatalyst can cover the shortage of extra UV light requirement,which exist in traditional refinery VOCs treatment approaches.Finally,this research could lay the foundation for actual use and future development of refinery VOCs treatment.