Noble metals-deposited TiO2 photocatalysts for photoreduction of CO2: Exploration of surface chemistry and a reflection on the importance of wavelength dependence

Mohit Yadav,Haythem S Basheer,Ádám Ágfalvi,Kornélia B Ábrahámné,Janos Kiss,Gyula Halasi,András Sápi,Ákos Kukovecz,Zoltán Kónya

doi:10.1016/j.apcata.2023.119434

Mohit Yadav, Haythem S Basheer + Show 7 more

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https://doi.org/10.1016/j.apcata.2023.119434

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Journal: Applied Catalysis A, General	Publication Date: Oct 5, 2023
Citations: 3	License type: cc-by-nc-nd

Affiliation: University of Szeged

Abstract

We report the enhanced photocatalytic performance of CO2 reduction by introducing noble metal-deposited TiO2 photocatalysts (NMD/TiO2) under both visible light irradiation (VLI) and UV. It was found that NMD-TiO2 samples demonstrated an expanded ability for light absorption, resulting in an improved photoefficiency for CO2 reduction and selectivity towards carbon monoxide (CO). The conversion yields of CO2 to CO followed the order: Rh >Ru >Pt and with Rh/TiO2 reached 10.65 μmol/gcat (under visible light) and 7.84 μmol/gcat (under UV), which are ∼3 and 10 times more as compared to pristine anatase TiO2 (0, and 2.43 μmol/gcat). Various factors were addressed including theoretical studies via DFT revealed that the formation of new impurity energy state levels in NMD/TiO2, which act as acceptor levels. Moreover, DRIFTS studies showed that the H-O-C-O and formyl (H2CO) species were the important intermediates towards the hydrogenation of CO2 to CO. Also, a charge transfer mechanism toward CO2 reduction was elucidated.

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