Near Infrared Light‐to‐Heat Conversion for Liquid‐Phase Oxidation Reactions by Antimony‐Doped Tin Oxide Nanocrystals

• Published in: Chemphyschem Vol. 24; no. 7; pp. e202200696 - n/a
• Main Authors: Tada, Hiroaki, Naya, Shin‐ichi, Sugime, Hisashi
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 03.04.2023
• Subjects: Ambient temperature; Antimony; antimony-doped tin oxide; Catalytic activity; Chemical reactions; Conduction bands; Energy gap; environmental purification; Heat; Hot electrons; Liquid phase oxidation; Luminous intensity; Nanocrystals; near infrared light; Near infrared radiation; Oxidation; oxidation reactions of organics; Photocatalysis; photothermal catalyst; Photothermal conversion; Solar energy; Tin dioxide; Tin oxides; oxidation reactions of organics; antimony-doped tin oxide; environmental purification; near infrared light; photothermal catalyst
• ISSN: 1439-4235; 1439-7641; 1439-7641
• DOI: 10.1002/cphc.202200696

Effective utilization of the sunlight for chemical reactions is pivotal for dealing with the growing energy and environmental issues. So far, much effort has been focused on the development of semiconductor photocatalysts responsive to UV and visible light. However, the near infrared and infrared (NIR‐IR) light occupying ∼50 % of the solar energy has usually been wasted because of the low photon energy insufficient for the band gap excitation. Antimony doping into SnO2 (ATO) induces strong absorption due to the conduction band electrons in the NIR region. The absorbed light energy is eventually converted to heat via the interaction between hot electrons and phonons. This Concept highlights the photothermal effect of ATO nanocrystals (NCs) on liquid‐phase oxidation reactions through the NIR light‐to‐heat conversion. Under NIR illumination even at an intensity of ∼0.5 sun, the reaction field temperature on the catalyst surface is raised 20–30 K above the bulk solution temperature, while the latter is maintained near the ambient temperature. In some reactions, this photothermal local heating engenders the enhancement of not only the catalytic activity and selectivity but also the regeneration of catalytically active sites. Further, the photocatalytic activity of semiconductors can be promoted. Finally, the conclusions and possible subjects in the future are summarized. NIR light irradiation of antimony‐doped tin oxide (ATO) with catalysts on the surface gives rise to significant enhancement in the activity and selectivity for liquid‐phase oxidation reactions of organics due to the local heating of the catalyst surface with the bulk solution temperature maintained at ambient temperature through effective conversion of the NIR light to heat by the ATO support.