Hierarchical TiO₂ nanorods with a highly active surface for photocatalytic CO₂ reduction

Abstract

Photocatalytic carbon dioxide reduction reaction (CO₂RR) has been considered as one of most effective ways to solve the current energy crisis and environmental problems. However, the practical application of photocatalytic CO₂RR is largely hindered by lock of efficient catalyst. Here, hierarchical titanium dioxide (TiO₂) nanostructures with a highly active {001} surface were successfully synthesized by a facile approach from metal Ti powders. The obtained hierarchical TiO₂ nanostructures were composed of TiO₂ nanorods, which have a diameter about 5–10 nm and a length of several micrometers. It is found that these nanorods have exposed {001} facets. On the other hand, these hierarchical TiO₂ nanostructures have a good light-harvesting efficiency with the help of TiO₂ nanorods component and large specific surface area. Therefore, these hierarchical TiO₂ nanostructures exhibit a much better activity for photocatalytic CO₂ reduction than that of commercial TiO₂ (P25). This high activity can be attributed to the synergistic effects of active surface, efficient charge transfer along nanorods and good light harvesting in the nanorod-hierarchical nanostructures.

摘要

光催化二氧化碳还原被认为是能够同时解决能源和环境问题的最有效方式之一。但高效的二氧 化碳还原催化剂的缺乏限制其实际应用。在本文中,我们成功合成了具有{001}高活性晶面的分级二 氧化钛纳米棒结构,纳米棒的直径为5~10 nm,长度为几个微米。分级纳米棒结构使得其具有更大的 比表面积,进而大大促进了光吸收。具有有效电荷传输、更大比表面积及更强光吸收的分级结构二氧 化钛纳米棒与商业的P25 二氧化钛相比具有更强的二氧化碳光催化还原性能。