The photothermal catalysis of the CO2 multicarbon conversion mechanism and dual interface-metal modulation of Cu-ZnO/SrTiO3 materials

Abstract

Under photothermal conditions, the efficient conversion of CO₂ into high energy density and high value-added multi-carbon products (C2+) has become a major challenge due to the high energy barrier that needs to be broken through in the C-C coupling process, the low efficiency of electron transfer and the instability of the reaction intermediate. In this paper, an interfacial-metal dual modulation strategy is proposed for the modulation of Cu-ZnO/SrTiO₃ photothermal catalytic materials constructed with strong interfacial effects, and the prepared catalysts exhibit a C₂H₆ production rate of 1.55 mmol·g⁻¹·h⁻¹ during photothermal-catalyzed CO₂ conversion, and the activity is still kept after 50 h of continuous operation. The results showed that the co-modulation between the interface and the metal co-catalysts enhanced the electronic interactions between the metal oxides and the carriers and formed interfacial states at the interface, thus effectively modulating the energy band structure of SrTiO₃, and the band gap value of the catalysts was significantly reduced. Meanwhile, the separation efficiency of photogenerated electron-hole pairs and the directional migration of multiple electrons of the catalysts were significantly improved. In addition, tests such as CO₂-TPD and in situ infrared confirmed that more active sites were provided for the catalysts, and the energy barrier of C-C coupling was lowered by this effective dual modulation, which was favorable for the photothermal catalysis of CO₂ reduction toward the multicarbon direction. The present study provides new ideas for realizing how to convert CO₂ into multicarbon products more efficiently in a photothermal catalysis system and the rational design of catalysts.