In situ hydrothermal etching fabrication of CaTiO3 on TiO2 nanosheets with heterojunction effects to enhance CO2 adsorption and photocatalytic reduction

• Published in: Catalysis science & technology 2019-01, Vol.9 (2), p.336-346
• Main Authors: Lin, Jinjin, Hu, Jiangshan, Qiu, Chengwei, Huang, Huijuan, Chen, Lu, Xie, Yanyu, Zhang, Zizhong, Lin, Huaxiang, Wang, Xuxu
• Format: Article
• Language: English
• Subjects: Adsorption; Basicity; Calcium titanate; Carbon dioxide; Carbon monoxide; Crystal structure; Etching; Heterojunctions; Heterostructures; Nanosheets; Organic chemistry; Photocatalysis; Photocatalysts; Reduction; Slaked lime; Solar energy conversion; Titanium dioxide
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c8cy02142b

Solar-driven carbon dioxide (CO2) reduction with water is an important and attractive approach for converting CO2 to fuel and chemicals. Developing intimate heterostructure photocatalysts is essential for efficient solar energy conversion. Here, we fabricated an efficient CaTiO3/TiO2 heterostructure composite by simple in situ hydrothermal etching of {001} facet-exposed TiO2 nanosheets with saturated calcium hydroxide solution. CaTiO3/TiO2 not only possesses an intimate contact heterostructure due to its matching band structures and similar crystal structures but also has enhanced-surface basicity to facilitate CO2 adsorption and activation for the CO2 conversion. Under irradiation, the CaTiO3/TiO2 sample greatly enhances photocatalytic CO2 reduction and shows CO production (11.72 μmol g−1 h−1) 5.6 times higher than that of bare TiO2 nanosheets. The excellent photocatalytic performance of the CaTiO3/TiO2 heterostructures is attributed to the intimate construction of CaTiO3 on TiO2 nanosheets to facilitate the separation of photogenerated charges and the basicity of CaTiO3 to provide more abundant active sites for CO2 adsorption. This study provides fundamental guidance for the rational design of efficient heterostructure photocatalysts for an outstanding photocatalytic CO2 reduction performance.