One-dimensional densely aligned perovskite-decorated semiconductor heterojunctions with enhanced photocatalytic activity

By using one-dimensional rutile TiO₂ nanorod arrays as the structure-directing scaffold as well as the TiO₂ source to two consecutive hydrothermal reactions, densely aligned SrTiO₃-modified rutile TiO₂ heterojunction photocatalysts are crafted for the first time. The first hydrothermal processing yielded nanostructured rutile TiO₂ with the hollow openings on the top of nanorods (i.e., partially etched rutile TiO₂ nanorod arrays; denoted PE-TNRAs). The subsequent second hydrothermal treatment in the presence of Sr²⁺ transforms the surface of partially etched rutile TiO₂ nanorods into SrTiO₃ nanoparticles via the concurrent dissolution of TiO₂ and precipitation of SrTiO₃ while retaining the cylindrical shape (i.e., forming SrTiO₃-decorated rutile TiO₂ composite nanorods; denoted STO-TNRAs). The structural and composition characterizations substantiate the success in achieving STO-TNRA nanostructures. In comparison to PE-TNRAs, STO-TNRA photocatalysts exhibit higher photocurrents and larger photocatalytic degradation rates of methylene blue (3.21 times over PE-TNRAs) under UV light illumination as a direct consequence of improved charge carrier mobility and enhanced electron/hole separation. Such 1D perovskite-decorated semiconductor nanoarrays are very attractive for optoelectronic applications in photovoltaics, photocatalytic hydrogen production, among other areas. Using one-dimensional rutile TiO₂nanorod arrays as the structure-directing scaffold as well as the TiO₂ source to two consecutive hydrothermal reactions, densely aligned SrTiO₃-modified rutile TiO₂ heterojunction photocatalysts are crafted for the first time. Such one-dimensional perovskite-decorated semiconductor nanoarrays exhibit high photocatalytic performance and are attractive for optoelectronic applications in photovoltaics, water-splitting, etc.