Preparation Of Titanium Dioxide Composite Material And Research On Its Photoelectrochemical Corrosion Resistance

With the development of the social economy,metal materials have become more and more widespread.However,due to the corrosion of metal materials,substantial economic losses and environmental damage have been caused.Therefore,we must take adequate measures to prevent decay.Since it was reported that nano-TiO₂ could produce photo-generated cathodic protection of metals under ultraviolet light irradiation,the use of photoelectric conversion of semiconductor materials to protect metals from corrosion has attracted wide attention from domestic and foreign researchers.This method is due to the permanent nature of the photoelectric conversion of semiconductor materials.In theory,it has the advantages of long-term anti-corrosion effect,environmental protection,and energy-saving,so it has a wide range of application prospects in the field of metal corrosion protection.GO was first prepared by the modified Hummers method in this paper,and TiO₂/GO composite materials with different ratios were prepared by the hydrothermal method.Then,An,TiO₂,and GO were used as raw materials,APS was used as the initiator,and in-situ oxidative polymerization was used.Prepare TiO₂/PANI and TiO₂/GO/PANI composite materials with different ratios.The material's structure,crystal form,and light absorption properties have been studied through FT-IR,XRD,UV-Vis DRS,and other methods.The results show that TiO₂ interacts with GO and PANI through surface chemical reactions;after doping with GO and PANI,the prepared TiO₂/GO,TiO₂/PANI,and TiO₂/GO/PANI nanocomposites did not appear new characteristic peaks and crystal structures.The addition of GO and PANI did not affect the crystallization behavior of TiO₂,Compared with TiO₂,the composite material has a significant increase in the absorption intensity in the ultraviolet and visible regions absorption edge is red-shifted.A series of TiO₂/GO/EP,TiO₂/PANI/EP,and TiO₂/GO/PANI/EP doubles were prepared on the surface of Q235 carbon steel with the synthesized nanocomposite particles as the filler,EP as the film-forming substrate,and NMP and n-butanol as the solvent functional in-situ composite coating.The photocurrent density and open-circuit potential photoelectric effect test were carried out under visible light to evaluate the photoelectrochemical conversion performance of the mixed layer.The results showed that different ratios of TiO₂/GO/EP,TiO₂/PANI/EP,and TiO₂/GO/PANI/EP.The composite coatings all have a photoelectric response.The photoelectric answer of the TiO₂/GO/PANI/EP-5 composite coating is the most obvious,the photocurrent density is 0.061A/cm²,the open-circuit voltage is reduced to-851m V,and the TiO₂/PANI/EP and the TiO₂/GO/PANI/EP composite coating has a specific photogenerated electron storage effect,which can continuously provide electrons to Q235 carbon steel in the dark state,and achieve the result of offering photogenerated cathodic protection for Q235 carbon steel in the dark form for a long time.Electrochemical impedance and polarization curve tests were carried out under light and dark conditions to evaluate the corrosion protection performance of the composite coating on metals.The results show that the mixed layer can provide good corrosion protection to carbon steel with or without light.And the TiO₂/GO/PANI/EP-5 composite coating has the highest anti-corrosion efficiency in the dark state,reaching 98.32%,the self-corrosion voltage is the largest,-0.002V,and the self-corrosion current density is the smallest,6.065×10^-7A/cm²,which has the best Excellent corrosion resistance.The self-corrosion voltage negatively shifted to-1.036V under light,and the self-corrosion current density increased to 2.214×10^-4A/cm²,indicating that the coating provides better photogenerated cathodic protection for Q235 carbon steel under a light.It shows that the TiO₂/GO/EP,TiO₂/PANI/EP,and TiO₂/GO/PANI/EP composite coatings can provide good coating shielding protection and semiconductor photogenerated cathodic protection for the Q235 carbon steel substrate.