Low-temperature Growth,Composite Structure And Photoelectrochemical Properties Of TiO₂ Nanorod Arrays

As a wide band-gap semiconductor material,titanium dioxide（TiO₂）has excellent physical and chemical properties such as stability,good optoelectronic properties,non-toxic and environmental protection,and thus has a wide range of research and application values in new energy,catalytic degradation,biomedicine and other fields.This paper focuses on the preparation and optimization of the structural properties of TiO₂ nanorod arrays,as follows:（1）The microemulsion-assisted hydrothermal growth was used to achieve well-crystallised TiO₂ nanorod arrays at low temperatures（less than 100°C）in fluorine doped tin dioxide glass（FTO）.Compared with the conventional hydrothermal method,the process is more efficient and the TiO₂ nanorod arrays prepared under the same conditions have better morphology and higher photovoltaic properties.This is mainly attributed to the addition of a precursor solution to the microemulsion system,which promotes the hydrolytic condensation reaction and reduces the reaction energy,resulting in easier nucleation of TiO₂nanoparticles at the solution-liquid-solid interface,thus effectively reducing the reaction temperature and increasing the growth rate.The process can also be applied to the preparation of other semiconductor nanomaterials.（2）Zinc oxide（ZnO）and TiO₂ have similar crystal structures and can form good heterostructures to improve the photoelectrochemical properties.Therefore,in this paper,the preparation of TiO₂/ZnO nanorod heterojunction arrays was achieved using a magnetron sputtering-assisted hydrothermal method,which is a simple and controllable process with universal applicability.The experimental results show that the TiO₂/ZnO nanorod heterojunction arrays exhibit superior photoelectrochemical performance compared to single TiO₂ and ZnO nanorod arrays,and the degradation efficiency of the heterojunction arrays is significantly improved compared to single arrays using methylene blue solution as the degradation target,and the photocurrent response is 1.7 times higher than that of TiO₂nanorod arrays and 2 times higher than that of ZnO nanorod arrays.This is mainly attributed to the increased specific surface area due to the formation of heterojunctions between TiO₂and ZnO on the one hand,and the increased charge transfer efficiency due to the interfacial gradient energy band structure on the other.（3）The TiO₂/BaTiO₃/Ce₂S₃ composite nanorod array structure was prepared by hydrothermal and ion deposition processes.Preliminary microstructural and fluorescence emission spectroscopy analysis showed that the introduction of BaTiO₃ ferroelectric layer to generate polarized electric field effectively enhanced the interfacial charge transfer efficiency of the composite structure,which was beneficial to the photoelectrochemical performance of the TiO₂/BaTiO₃/Ce₂S₃ composite nanostructure.