Properties Of Porphyrin And Metallic Porphyrin Sensitized Titanate Nanotubes

Titanate nanotubes （TNTs） possess larger specific surface area, high catalytic activitynon-toxic etc, and is widely used in environmental protection and renewable energy, etc.Because TNTs only use ultraviolet light which is about5%of the total solar energy, it limites theeffective use of solar energy for titanate nanotubes. In this paper, we used the carboxyl porphyrinand metal carboxyl porphyrin sensitized TNTs as the research object, making the spectralresponse of TNTs extend to visible light to research their adsorption and photocatalyticproperties because porphyrin in the visible light region has strong absorption characteristics.Detailed content as follows:1、tetrabutyl titanate and four carboxyl phenyl porphyrin as the substrates, then we got goodscattered TCPP/TiO₂gel and zinc, copper porphyrin/TiO₂gel by the method of sol-gel, and thencarboxyl phenyl porphyrin titanate nanotubes （TCPP-TNTs）、copper carboxyl porphyrin titanatenanotubes （CuTCPP-TNTs） and zinc carboxyl porphyrin titanate nanotubes （ZnTCPP-TNTs）were synthesized with hydrothermal treatment of TCPP-TiO₂gel、CuTCPP-TiO₂gel andZnTCPP-TiO₂gel respectively. The morphology and structure were investigated by scanningelectron microscope（SEM）、 transmission electron microscope（TEM） and X-Ray PowderDiffraction （XRD）. The specific larger surface area of prepared nanotubes determined by N2adsorption/desorption. DRS illuminated the porphyrin and metallic porphyrin titanatenanotubes combined by chemical bonds.2、Through the exploration of adsorption conditions:the calcimined temperature, alkalinityor acidity and solution concentration, we knew that the adsorption ability of metallic porphyrinsensitized nanotubes were higher than porphyrin sensitized nanotubes at the same conditions,what was more, adsorption abilities between different metals were also different, in the sameconcentration of methylene blue solution, the strongest adsorption ability was CuTCPP/TNTs of55mg/g, in the middle is ZnTCPP/TNTs, and adsorption ability of TCPP/TNTs was the weakestof35mg/g. In the study of isothermal adsorption balance model, they were Langmuir singlemolecule layer isothermal adsorption equation, However, in dynamic study, TCPP/TNTs and ZnTCPP/TNTs were properly evalued by the pseudo-first-order model, and CuTCPP/TNTsconformed to the pseudo-first-order model too, it is said that thermodynamic model and kineticmodel of porphyrin sensitized nanotubes and metal porphyrin sensitized nanotubes have notchanged.3、 In the photocatalytic test, we explored the influential factors of photocatalyticdegradation methylene blue: temperature, concentration and the different preparation methods oftitanate nanotubes. The results showed that in the visible irradiation, the photocatalytic effect ofCuTCPP/TNTs was the best than ZnTCPP/TNTs and TCPP/TNTs, of course which was notdivided to its good adsorption ability.4、After five times repetitive adsorption experiments, the good repetitive utilization rate ofZnTCPP/TNTs reached to87.56%, adsorption effect of CuTCPP-TNTs-100℃reached to83.69%, which can provide some test basis for the research adsorption materials.