Highly Ordered TiO₂-ATO Three-dimensional Macroporous Heterostructures:Controlled Fabrication And Photoelectrochemical Performance

Energy crisis is becoming more and more serious with the survival and development of human beings,and it is imperative to explore new environmentally friendly energy sources.TiO₂ semiconductor is a kind of widely studied photocatalysts which is widely used in photoelectrochemical water splitting.TiO₂ itself has good light stability and the band gap position meets the requirements of photoelectrochemical water splitting,but it has a large band gap?3.2 eV?with poor ability in collecting electrons and almost no absorption of visible light,all of these defects seriously restrict its development in photoelectrochemical water splitting to produce hydrogen.Therefore,optimization and modification of single TiO₂ is an important research work.Focused on those defects,combined with semiconductor modification researching status,we prepared a 3D ATO inverse opal?Sb-doped SnO₂?as a conductive scaffold to composite with TiO₂ and then deposited the Au nanoparticles for further modification,and systematically analyzed the photoelectrochemical properties of these composite structures.The main contents are as follows:?1?Using FTO conductive glass as the substrate,we prepared the 3D ATO inverse opal structure with vertical settlement self-assembly and sol-gel method,and the 3D ATO IO/TiO₂ composite structural was then prepared by chemical bath deposition method.Characterization analysis showed that the composite structural possessed a 3D macroporous structure and the intersecting surface thickness was about 3.4?m,the TiO₂nanorods grew densely and uniformly around the ATO IO conductive scaffold,and the photoelectrochemical performance of the modified composite material had been improved.The test showed that the concentration of precursor solution and reaction time would both influence the material pattern,and then effect the photocatalytic performance.When the concentration of TiCl₄ solution was 0.05 mol/L and the reaction time was 3 h,the composite material had the best photocurrent density of 1.48 mA/cm² via 1.23 V vs.RHE.?2?Au nanoparticles were deposited in 3D ATO IO/TiO₂ composite structure formed 3D ATO IO/TiO₂/Au composite structure.The characterization showed that Au nanoparticles were deposited around TiO₂ nanorods with a diameter of about 5 nm.Photocurrent analysis of 3D ATO IO/TiO₂/Au composite structure showed that,compared with 3D ATO IO/TiO₂composite structure,the resistivity reduced and the carrier density increased.Photoelectric properties of the material were significantly increased,the photocurrent density reached2.39 mA/cm² via 1.23 V vs.RHE.