Rational Surface Engineering of Anatase Titania Core–Shell Nanowire Arrays: Full-Solution Processed Synthesis and Remarkable Photovoltaic Performance

The high-performance of a well-aligned 1D nanostructured electrode relies largely on a smart and rational modification with other active nanomaterials. Herein, we present a facile solution-based route to fabricate a well-aligned metal oxide-based core–shell hybrid arrays on TCO substrate. Demonstrated samples included nanowire@nanoparticle (TNW@NP) or nanowire@nanosheet (TNW@NS) with a unique porous core/shell nanowire arrays architecture in the absence or presence of DETA during the solvothermal treatment process. The “alcoholysis” and “ripening” growth mechanism is proposed to explain the formation of honeycomb-like nanosheets shell on nanowires core. Based on careful control of experimental condition, a novel double layered TiO2photoanode (DL-TNW@NS-YSHTSs) consisting of 16 μm thick TNW@NS under layer and 6 μm thick yolk–shell hierarchical TiO2microspheres (YSHTSs) top layer can be obtained, exhibiting an impressive PCE over 10% at 100 mW cm–2, which can be attributed to the well-organized photoanode composed of hierarchical core–shell arrays architecture and yolk–shell hollow spheres architecture with synergistic effects of high dye loading and superior light scattering for prominent light harvesting efficiency.