Ni(II) Tetra(4-carboxylphenyl)porphyrin-Sensitized TiO2 Nanotube Array Composite for Efficient Photocatalytic Reduction of CO2

• Published in: Journal of physical chemistry. C 2022-06, Vol.126 (23), p.9742-9752
• Main Authors: Xiao, Tongxin, Chen, Ying, Liang, Yuning
• Format: Article
• Language: English
• Subjects: C: Chemical and Catalytic Reactivity at Interfaces
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/acs.jpcc.2c02335

The photocatalytic conversion of CO2 into hydrocarbon fuels by utilizing abundant solar energy is a promising and eco-friendly approach to address the energy crisis and global warming. In this work, the sensitizer Ni­(II) tetra­(4-carboxylphenyl)­porphyrin (NiTCPP) was successfully combined with TiO2 nanotube arrays (TiO2NTs) by three methods, and their performances in the photocatalytic reduction of CO2 under simulated solar irradiation were studied. The results showed that NiTCPP/TiO2NTs exhibit a greatly ameliorated photocatalytic activity, and the photocatalytic reduction activities of NiTCPP/TiO2NTs prepared by different methods were different. The catalyst prepared by the impregnation method displayed the highest photoreduction efficiency. The reduction rate of CO2 into CH4 was up to 33.89 μmol/cm2/h with a quantum efficiency of 0.65% (at 420 nm), about 5 times that of the bare TiO2NTs. The introduction of NiTCPP not only efficiently expands the light absorption range but also enhances the charge separation efficiency. Furthermore, a possible mechanism of its CO2 photoreduction performances was systematically presented.