Bicrystalline TiO2 heterojunction for enhanced organic photodegradation: engineering and exploring surface chemistry

摘要: Bicrystalline TiO2 anatase/rutile (TiAR) and anatase/brookite (TiAB) have been extensively studied for photocatalysis, but the differences in their surface chemistry (defect non-defect) are still not well understood. Here we integrated treatment effect phase heterojunction to engineer of TiAR TiAB. TiAB were either reduced by H2 or oxidized H2O2. consisted nanoparticle (anatase) patched nanobricks (rutile), while was predominated with nanorods. After treatment, both them retained morphologies, crystal structure, porosities. We found that untreated demonstrated a twice higher activity than methylene orange (MO) degradation, mainly because more facilitated charge transfer between anatase brookite interface, exposure Ti3+/O2− radicals, positively charged Interestingly, H2-reduced showed decrease compared counterparts, H2O2-treated went through different mechanisms. H2O2 induced gradual TiAB(H2O2), depending on temperature. By contrast, TiAR(H2O2) three times enhancement comparable most active The findings this work provided new insights rather crystallinity, particle size, area, band gap, photocatalytic performance is closely associated junction, defect sites (Ti3+/vacancy).