Selective Growth of High‐Density Anatase {101} Twin Boundaries on High‐Energy {001} Facets

Abstract

Crystal lattices with abundant twinning boundaries are rendered with unique electrical, optical, chemical, and mechanical characteristics; however, it is highly challenging to controllably fabricate such material structures in a facile and high‐throughput manner. Herein, a facile feeding‐triggered growth approach to selectively grow high‐density anatase TiO2 {101} twin boundaries (TBs) on the {001} faceted high‐energy surfaces of anatase TiO2 single crystals is reported. The growth of the TB rich structures is found to be highly sensitive to the amount of feeding TiN and HF concentrations. The resultant anatase {101} twinned structures are systematically characterized and analyzed. When compared with the twin structure‐free anatase TiO2 single crystals, the obtained anatase TiO2 single crystals with the densely populated {101} TBs on the {001} faceted surfaces exhibit a significantly enhanced activity toward the photoelectrocatalytic oxidation of water and organic compounds. The demonstrated twin structure growth approach herein is adaptable to grow rich twin structures on other crystals for diversified applications.