Enhanced Tribocatalytic CO₂ Reduction by TiO₂ Nanoparticles

The development of science and technology has brought convenience to our life, however, the CO₂ emission in industrial production has aggravated the greenhouse effect and brought great damage to the ecological environment. Therefore, this study investigated the reduction process of CO₂ under the condition of tribocatalysis. The effect of the rotational speed of the magnetic stirrer, the content of catalyst, the type of sacrificial agent, the reaction time and the initial CO₂ content on the tribocatalytic CO₂ reduction products was investigated by using nano-TiO₂ (P25) as a catalyst. Under the optimal conditions, replacing the reaction solution H₂O with difficult-to-degrade rhodamine B, methylene blue and methyl orange solutions further increased the contents of CO₂ reduction products: CO (124 μmol h^-1 g^-1), C₂H₆ (49 μmol h^-1 g^-1), CH₄ (24 μmol h^-1 g^-1), C₂H₄ (3 μmol h^-1 g^-1) and H₂ (2 μmol h^-1 g^-1). The dual control of organic pollutants and CO₂ emission problems was realized. Finally, the active substances (e^-, ^•OH and ^•O₂ ^-) in the tribocatalytic process were proved to be the key for efficient CO₂ reduction and realization of organic pollutants by electron paramagnetic resonance spectroscopy tests. The method also has a great potential to crack H₂ in H₂O, which can alleviate the greenhouse effect caused by CO₂ emission and effectively deal with water pollutants and regenerated new energy, which is in line with the national requirements of the circular economy, and is also conducive to the promotion of the sustainable and healthy development of the energy industry.