| As a common photocatalyst,titanium dioxide（TiO2）is one of the most promising material because of its outstanding properties,such as low cost,nontoxicity and chemical stability.TiO2 could help to solve the problems of energy shortage and enviornment pollution,which are becoming more and more severe all around the world.However,with the rapid pace of industry development and technology revolution,the requirements and demands of photocatalysts are increasingly higher.Moreover,some of the drawbacks of typical photocatalysts,such as large band gap and low energy transfer efficiency,are imposing restrictions on the development of TiO2 in the photocatalysis field.Consequently,how to enhance TiO2’s photaocatalysis efficiency and broaden its light response range under visible-light become a focus of current research.Inspired by the abundant biomorphic structures in nature,this study raises a concept concerning biomorphic template.Based on different butterfly wings,a series biomorphic TiO2 are fabricated by sol-gel method.The obtained samples are also detected to find out how the dimensions of periodic structure affect the photonic performance of these samples respectively.Meanwhile,gold nanoparticles are dispersed into the biomorphic TiO2 photonic crystal（TiO2-BMPC）to fabricate Au/TiO2-BMPC on the basis of Euploea mulciber butterfly as template.According to the results of charaterizations,the properties and photonic performance and photocatalytic efficiency are detected,which could be used to analyze how the slow photon effect of photonic structure helps to enhance the SPR intensity of gold nanoparticles.All the work we done could offer us new sights and models for the studies of photocatalytic materials.The main contents and results are as follows:1.Based on a modified sol-gel method,biomorphic TiO2 material is fabricated using butterfly wings as templates.The obtained samples own a well-replicated structure of butterfly wing scales,including ridges,struts and ribs.2.On the basis of Thaumantis diores,Kallima inachus and Euploea mulciber butterfly wings who have similar periodic hierachical structures,a series of biomorphic TiO2 are synthesized.Some detections and analysis have been done to find out the connection between the dimensions and photonic performance of periodic hierachical structures under visible-light.The results show that only the sample templated from Euploea mulciber butterfly wings gives a good photonic performance,with the existance of reflection spectra at 420nm and 600nm respectively.With the increasement of the size“window”structure,the wavelength of the reflection spectrum will have a red shift.Meanwhile,the more ribs it have,the more possiblely the structure will give a good photonic performance under visible-light.3.Using Euploea mulciber butterfly wings as biomorphic template,biomorphic Au/TiO2 photonic crystal sample（Au/TiO2-BMPC）is obtained.The results show that the original structures of butterfly wing scales are well-replicated in the Au/TiO2-BMPC samples.Gold nanoparticles are well-dispersed on the TiO2 matrix,with an average size of 9 nm.It is convinced that there is an enhenced light harvesting under visible-light,due to the slow photon effect of photonic structure,which happens when the wavelength of slow photon effect matches the SPR wavelength of gold nanoparticles.As a result,the SPR intensity of gold nanoparticles could be enhanced under visible-light irradiation.4.The degradation of methyl orange test is used to detect the photocatalytic efficiency of Au/TiO2-BMPC samples.The results show that Au/TiO2-BMPC is able to degrade MO completely within 240 min.Compared to the contrast samples,the photocatalytic rate of Au/TiO2-BMPC is 5 times than that of crused Au/TiO2-BMPC,and 7times than that of Au/TiO2-P25.The enhanced photocatalytic property could mainly ascribed to the co-work of photonic structures and gold nanoparticles.Furthermore,the hierarchical porous structures of butterfly wings offer more active sites for the photocatalysis process,which could also help increase the photocatalytic efficiency of Au/TiO2-BMPC samples. |
