Preparation Of TiO₂ Via Modification Of Metal Oxides And Doping Of Fe³⁺

Compared with other semiconductors,titanium dioxide is a good and promising photocatalytic material.In the field of photocatalysis,TiO₂ is widely used in photocatalytic degradation of organic compound and photocatalytic hydrogen production.However,there are two obvious disadvantages of titanium dioxide as a photocatalytic material:First,titanium dioxide has a wide band gap and can only absorb ultraviolet light.The visible light is unresponsive;in addition,the recombination of photogenerated electron-hole rate is fast,and the utilization efficiency of the photo-generated carrier is lower.In view of its problems,it is hoped that the activity of the titanium dioxide photocatalyst can be enhanced by modification or doping,and the photoresponse range can be extended to the visible light band.In this paper,we have adopted the anodic oxidation method for the TiO₂ nanotube arrays structure,which has the characteristics of neatly arranged and highly ordered,and is used as a“nanoreactor”in subsequent experiments to introduce impurities to modify or doping.In the process of modifying nanotubes,on the one hand,the TiO₂ nanotubes are modified by metal oxides,and through the method of preparing the metal salt solution in the nanotubes and then using the thermal decomposition method,it can prepare a good nanotube heterojunction.Thin film structure,and the feasibility and photocatalytic effect of the preparation method were obtained by characterization test and photocatalytic result analysis.When Zn（Ac）₂ precursor solution concentration was0.6 mol/L under UV light,ZnO/TiO₂ heterojunction film can degrade about 55%of methyl orange after 120 min.The Cu₂O/TiO₂ heterojunction film can degrade about15%after 120 min when the Cu（Ac）₂ precursor solution is 0.3 mol/L under visible light.In addition,prepared by the same preparation method,CeO₂/TiO₂ heterojunction film has a photocatalytic degradation of methyl orange at about 17%when the Ce（NO₃）₃precursor concentration is 0.5 mol/L.On the other hand,this paper also proposes a new preparation method of iron-ion doping TiO₂ nanotubes,which is to use Fe³⁺salt solution to induce crystallization of TiO₂ directly to prepare Fe³⁺doped TiO₂ nanotubes.The method is very novel.The conditions and preparation process of low temperature induced crystallization were obtained.The photocatalytic activity of Fe³⁺doping TiO₂ nanotubes was improved by characterization and test.0.2 mol/L Fe³⁺doping TiO₂ nanotubes shows best and strong response to ultraviolet light or visible light and extends the photo response range of TiO₂ under visible light,with good photocatalytic results.