Fabrication of N-doped TiO2 coatings on nanoporous Si nanopillar arrays through biomimetic layer by layer mineralization

摘要

Si/N-doped TiO core/shell nanopillar arrays with a nanoporous structure are fabricated through a simple protein-mediated TiO deposition process. The Si nanopillar arrays are used as templates and alternatively immersed in aqueous solutions of catalytic molecules (protamine, PA) and the titania precursor (titanium(IV) bis(ammonium lactato)dihydroxide, Ti-BALDH) for the layer by layer mineralization of a PA/TiO coating. After a subsequent calcination, a N-doped TiO layer is formed, and its thickness could be controlled by varying the cycles of deposition. Moreover, the nanoporous structure of the Si nanopillars strongly affects the formation of the TiO layer. The obtained Si/TiO nanocomposites show significantly improved solar absorption compared with commercially purchased TiO nanoparticles.