Enhanced CO[sub.2] Photoreduction over Bi[sub.2]Te[sub.3]/TiO[sub.2] Nanocomposite via a Seebeck Effect

• Published in: Catalysts 2022-10, Vol.12 (11)
• Main Authors: Lei, Yiming, Jia, Zewei, Hu, Huilin, Liu, Lequan, Ye, Jinhua, Wang, Defa
• Format: Article
• Language: English
• Subjects: Methylene blue; Optical properties; Thermoelectricity
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal12111323

The activation of carbon dioxide (CO[sub.2]) molecules and separation/transfer of photoinduced charge carriers are two crucial factors influencing the efficiency of CO[sub.2] photoreduction. Herein, we report a p-type Bi[sub.2]Te[sub.3]/commercial TiO[sub.2] (pBT/P25) nanocomposite for enhanced CO[sub.2] 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 CO[sub.2] 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 CO[sub.2] molecules and promotion of charge separation/transfer, we achieved the highest CO evolution rate over pBT(2)/P25 of 19.2 μmol·g[sub.cat] [sup.−1]·h[sup.−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 CO[sub.2] reduction via promoting the charge carriers' separation/transfer.