Photothermal reverse water gas shift reaction is one of the promising methods to palliate global energy and environmental issues. Searching for catalysts with high activity and CO selectivity for CO 2 conversion has been attracting extensive attention. In this work, Ni nanoparticleloaded N-doped CeO 2 (Ni/N-CeO 2 ) composite catalysts were synthesized using a three-step method. Under light irradiation, the optimal Ni/N 5.0 -CeO 2 exhibited a CO yield rate of 20.9 mmol• g cat −1 •h −1 with almost 100% of CO selectivity via photothermal CO 2 reduction. As a comparison, Ni/CeO 2 , without nitrogen doping, showed a high CH 4 selectivity. The strong light absorption of Ni/N 5.0 -CeO 2 mainly by loading of Ni nanoparticles and the enhanced adsorption/activation of CO 2 molecules due to increased oxygen vacancies in N 5.0 -CeO 2 by N-doping were supposed to account for the excellent catalytic performances. The doping of nitrogen was of particular importance for the formation of N−H bonds, which could modulate the reaction pathway for promoting the reduction of CO 2 toward CO while suppressing the undesirable CO 2 methanation process.

The activation of carbon dioxide (CO2) molecules and separation/transfer of photoinduced charge carriers are two crucial factors influencing the efficiency of CO2 photoreduction. Herein, we report a p-type Bi2Te3/commercial TiO2 (pBT/P25) nanocomposite for enhanced CO2 photoreduction. Upon light irradiation, a temperature gradient formed in pBT induces the Seebeck effect to build a thermoelectric field, which promotes the charge carriers’ separation/transfer. Additionally, pBT with a strong light absorption capacity generates the photothermal effect favoring the activation of CO2 molecules. In addition, the excellent electric conductivity and large work function render pBT an efficient cocatalyst for further improving the charge carriers’ separation/transfer. Owing to the synergistic enhancement effect of pBT on the activation of CO2 molecules and promotion of charge separation/transfer, we achieved the highest CO evolution rate over pBT(2)/P25 of 19.2 μmol·gcat−1·h−1, which was approximately 5.5 times that of bare P25. This work suggests that a thermoelectric material/semiconductor nanocomposite could be developed as an efficient photo-thermo-electro-chemical conversion system for enhanced CO2 reduction via promoting the charge carriers’ separation/transfer.

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