The Preparation Of Bi₂MoO₆/Au/TiO₂ Ternary Photocatalytic Films And Research On Its Catalytic Performance

Semiconductor photocatalysis technology has become one of the effective solutions to solve problem of environmental pollution and energy shortages.While,developing efficient photocatalyst is the key to semiconductor photocatalysis technology to practical use.TiO₂,Over the past few decades,TiO₂,as classic photocatalyst,have attracted a great deal of attention in photocatalysis field,for their strong oxidizing power,simple preparation method,easy getted,nontoxicity,and environmentally friendly feature.TiO₂ is a wide band gap semiconductors?Eg = 3.2 eV?,it can only absorb ultraviolet light??<400 nm,only about 4%energy of the surface of earth?,and has narrow light-absorption range,in addition,the photogenerated electron-hole can easy combine,it is difficult to transfer to surface of photocatalyst to involve in redox reactions,resulting reduced quantum efficiency,and further reducing light energy utilization efficiency.Therefore,domestic and foreign scholars have made many efforts in response to these issues,including metal doping,elemental doping,surface photosensitization,semiconductor combination,structural control and so on,expecting to improve the photoactivity of TiO₂.In this paper,TiO₂ nanofiber films,Au/TiO₂ NFF,Bi₂MoO₆/TiO₂ binary complex,and Bi₂MoO₆/Au/TiO₂ ternary complex were prepared,the microstructure,crystal structure,elemental valence,spectroscopy and electrochemical properties of the prepared samples were analyzed by SEM,XRD,XPS,UV-Vis,PL and photocurrent.the microstructure,crystal structure,elemental valence,spectroscopy and electrochemical properties of the prepared samples were analyzed by SEM,XRD,XPS,UV-Vis,PL and photocurrent.At the same time,the photocatalytic performance of samples was evaluated by degradation MB,the mechanism of enhanced photocatalytic activity was discussed.The main contents of this paper are as follows:?1?Taking titanium tablets as the substrate,TiO₂ nanofiber film?TiO₂ NFF,TiO₂ nanofiber film?was prepared by hydrothermal method.The thin film was close to the titanium substrate,and it was not easy to fall off.The prepared film structure is easier to recycle than the TiO₂ powder,which is beneficial for the practical utilization of photocatalysts.TiO₂ NFF can absorb visible light,and under the visible light irradiation after 100 min,the degradation efficiency of MB can reached 19.14%,which may be attributed that TiO₂ NFF can capture the visible light to accelerate the process of photosensitive due to its unique nanostructure.TiO₂ can absorb visible light,and the visible light irradiation after 100 min,the degradation efficiency of MB reached 19.14%,which may be due to the unique nano-nanofibers nanofibers can capture the visible light to accelerate the process of photosensitive light,Au nanoparticels?Au NPs?were then deposited on the surface of TiO₂ film using microwave-assisted chemical reduction process.The results show that the loading of Au NPs have significantly enhanced light absorption in the visible region,and promotes the separation of photogenerated carriers.Introducing Au NPs further enhances the absorption of visible light and promotes the separation of photogenerated carriers.The photocurrent intensity of 0.8 Au/TiO₂ NFF was more than twice that of pure TiO₂,and the corresponding degradation efficiency of MB can reach 98.22%after 100 min under ultraviolet light irradiation.?2?Self-assembled flake-like Bi₂MoO₆ was grown on the surface of TiO₂ NFF under alcohol thermal condition,The study found that Bi₂MoO₆/TiO₂ binary composite has high purity and good stability,Compared with pure TiO₂,the absorption edges of all Bi₂MoO₆/TiO₂ composites exhibit the slight red shift toward the visible light region by the hybridization with Bi₂MoO₆.And the recombination of photogenerated electron-hole pairs is greatly restrained.The photocurrent intensity of 0.8 Bi₂MoO₆/TiO₂ composite is almost three times than that of pure TiO₂ NFF.In addition,the composite almost complete degradation of MB after 100 min under visible light irradiation.?3?Bi₂MoO₆/Au/TiO₂ ternary nano photocatalytic materials were prepared by alcohol thermal reaction using Au/TiO₂ NFF as the reaction template.The study found that the structure of Bi₂MoO₆/Au/TiO₂ ternary composite is TiO₂ NFF as the bottom plate,followed by covering Au NPs and Bi₂MoO₆.The co-modification of Au NPs and Bi₂MoO₆ greatly enhanced the absorption of visible light from two aspects.The recombination of photogenerated electron-hole pairs was further inhibited.Under ultraviolet light irradiation,Bi₂MoO₆/Au/TiO₂ ternary composite exhibits the highest activity and the corresponding degradation percentage is 98.91%after 30 min irradiation.