Facile synthesis of ultrasmall TiO2 nanocrystals/porous carbon composites in large quantity and their photocatalytic performance under visible light

Abstract

In this paper, we demonstrate a facile and scalable route to the preparation of composites containing ultrasmall TiO₂ nanocrystals and porous carbon matrix. In this method, the titanium ions are covalently introduced to polymer chains and transformed into TiO₂ nanocrystals directly in solid matrices, which allows the generation of well dispersed TiO₂ nanocrystals with small size in the entire carbon matrix. To our knowledge, this is the first time that ultrasmall TiO₂ nanocrystals are incorporated into a bulk porous carbon matrix. In comparison with pure TiO₂ particles, the composites exhibit significant improvement in photocatalytic degradation of methyl blue under visible light irradiation, which might be attributed to the ultrasmall size of TiO₂ nanocrystals as well as the high separation efficiency of photogenerated electrons and holes based on the synergistic effect between TiO₂ nanocrystals and carbon matrices. Furthermore, the composites could be easily recycled without obvious activity loss.