Photonic crystal structural-induced Cu3SnS4/Ti3+-TiO2 p-n coaxial heterojunction arrays for light-driven H2 production and pollutant degradation

By combining the n-type Ti3+ self-doped TiO2 photonic crystal structure with p-type ternary semiconductor Cu3SnS4, a new potential nanostructure of photonic crystal structural-induced p-n coaxial heterojunction arrays (denoted as CTS/Ti3+-PhC-TNAs) was designed and successfully fabricated by periodic pulse anodic oxidation combined with in-situ self-assembly technique. To be used in photocatalytic H-2 production and organic pollutant removal after optimizing both the structure and Ti3+ doping ratio, CTS/Ti3+-PhC-TNAs exhibited significantly enhanced photocatalytic activities of 159.29 +/- 1.7 mu mol center dot h(-1)center dot m-(2) for H-2 evolution and 0.08308 h(-1)center dot m(-2) for methyl orange degradation under simulated sunlight irradiation, which is 9.4 and 3.1 times higher than that of the PhC-TNAs. Detailed investigations revealed that the improved photoactivity of CTS/Ti3+-PhC-TNAs can be attributed to the accelerated photogenerated electron-hole separation at p-n heterojunction interfaces, the facilitated electron transfer along the coaxial heterojunction arrays and the enhanced light-harvesting through the unique designed photonic crystal composite structure as well. The present study shows a new insight and significantly improvement of photoactivity when Cu3SnS4 is introduced to form a p-n coaxial heterojunction arrays with photonic crystal structured TiO2, which provides a new means to design and fabricate novel film photocatalyst for high efficient solar energy conversion and photodegradation. (C) 2017 Elsevier Ltd. All rights reserved.