Shanghai Institute of Ceramics, Chinese Academy of Sciences: Progress in photocatalytic reduction of carbon dioxide by hydrogenated blue titanium dioxide

[Introduction]

Recently, the research group of photoelectric conversion materials and devices of the State Key Laboratory of High Performance Ceramics and Ultrastructure of Shanghai Institute of Ceramics, Chinese Academy of Sciences, has made important progress in the research of photocatalytic selective reduction of carbon dioxide to prepare high value-added methane. Related research results are published in ACS Catalysis under the title "Hydrogenated Blue Titania for Efficient Solar-to-Chemical Conversions: Preparation, Characterization, and Reaction Mechanism of CO2 Reduction", and have applied for invention patents. The research was funded by the National Key Research and Development Program, the National Natural Science Foundation of China, the Chinese Academy of Sciences, and the Shanghai Science and Technology Commission.

[Graphic introduction]

Figure 1 Hydrogenated blue titanium dioxide high-efficiency photocatalytic CO2 reduction, hydrogen production and organic degradation

Figure 2 Performance characterization

Hydrogenated blue titanium dioxide (a: absorption of the solar spectrum, b: microstructure, c, d: in situ infrared spectroscopy of photocatalytic reduction of CO2)

【research content】

Through the design and creation of a new hydrogenated blue titanium dioxide material, the research group successfully realized the high-efficiency conversion of CH4 by water reduction under near ambient pressure, and studied the reaction mechanism by in-situ diffuse reflection Fourier transform infrared technology. A large number of CO2 effluxes have led to global problems such as increased greenhouse effect, rising sea level, and acidification of water bodies. How to convert CO2 into useful energy chemicals has become a research hotspot. Catalytic reduction of CO2 with clean, renewable solar energy is considered an ideal way to address energy crises and environmental pollution. Currently widely used catalysts for photocatalytic reduction of CO2 are supported precious metal (such as Pt, Pd, Au, Ag) semiconductor materials, and the cost is high. TiO2 has attracted extensive attention in the field of photocatalytic reduction of CO2 due to its advantages of low cost, easy availability and good stability. However, its wide band gap (3.2 eV), photogenerated electron-hole pair (e??h+) complex, and many side reactions make photocatalytic performance and utilization of solar energy inefficient. In view of the above problems, the research group prepared a hydrogenated blue titanium dioxide containing a large number of surface defects by a simple low-temperature solvothermal method using a solution of an alkali metal lithium-containing ethylenediamine as a solvent from the design and preparation of the material and the band gap control. The material exhibits excellent solar photocatalytic reduction of CO2 performance. The space-time yield of CH4 is 16.2 μmol g1h1 and selectivity is 81%, which are currently reported to be optimal. Through the kinetic isotope effect experiment and cooperation with the East China University of Technology Han Yifan research group, the research also used in-situ infrared technology to study the reaction process and reaction mechanism. The study found that the material also showed good catalytic performance for photocatalytic hydrogen production and degradation of organic pollutants.