Surface energy-driven solution epitaxial growth of anatase TiO2 homostructures for overall water splitting
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第11期
论文作者：Shi Li Luoyuan Ruan Shanpeng Wang Zhiyu Wang Zhaohui Ren Gaorong Han
文章页码：139 - 144
摘 要：Titanium dioxide（TiO2） has been extensively investigated as a photocatalyst for water splitting to produce H2. However, an overall water splitting by using anatase TiO2 is extremely difficult due to the short lifetime of holes. In this work, we propose that a surface energy decrease from {001} to {101} of anatase TiO2 is able to drive an epitaxial growth. A novel anatase TiO2 homostructure has been successfully synthesized via a facile hydrothermal route, where {101} semi-pyramid nanoparticles epitaxially grew on the both sides of the {001} nanosheets. The epitaxial relationship between the nanoparticles and the nanosheets has been characterized to be {001}//{001} of anatase TiO2. For the first time, it is interesting to find that the homostructure with 12 wt% of {101} semi-pyramid can significantly improve the H2 evolution rate by nearly 5 times compared to the pure nanosheets under the ultraviolet irradiation.More importantly, such homostructure enables 10.78 μmol g-1h-1 of O2 production whereas the pure nanosheets cannot evolve detectable O2 gas. Meanwhile, the time-resolved photoluminescence analysis indicates that the mean lifetime of the holes is increased from 2.20 ns of the nanosheets to 3.59 ns of the homostructure, accounting for the observed overall water splitting. The findings suggest that constructing a homostructure by a surface energy strategy could be promising towards overall water splitting, which may be applicable to other photocatalytic materials.
Shi Li1，Luoyuan Ruan1，Shanpeng Wang2，Zhiyu Wang1，Zhaohui Ren1,2，Gaorong Han1
1. State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University2. State Key Laboratory of Crystal Materials, Shandong University
摘 要：Titanium dioxide（TiO2） has been extensively investigated as a photocatalyst for water splitting to produce H2. However, an overall water splitting by using anatase TiO2 is extremely difficult due to the short lifetime of holes. In this work, we propose that a surface energy decrease from {001} to {101} of anatase TiO2 is able to drive an epitaxial growth. A novel anatase TiO2 homostructure has been successfully synthesized via a facile hydrothermal route, where {101} semi-pyramid nanoparticles epitaxially grew on the both sides of the {001} nanosheets. The epitaxial relationship between the nanoparticles and the nanosheets has been characterized to be {001}//{001} of anatase TiO2. For the first time, it is interesting to find that the homostructure with 12 wt% of {101} semi-pyramid can significantly improve the H2 evolution rate by nearly 5 times compared to the pure nanosheets under the ultraviolet irradiation.More importantly, such homostructure enables 10.78 μmol g-1h-1 of O2 production whereas the pure nanosheets cannot evolve detectable O2 gas. Meanwhile, the time-resolved photoluminescence analysis indicates that the mean lifetime of the holes is increased from 2.20 ns of the nanosheets to 3.59 ns of the homostructure, accounting for the observed overall water splitting. The findings suggest that constructing a homostructure by a surface energy strategy could be promising towards overall water splitting, which may be applicable to other photocatalytic materials.
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