Ultra-Durable Photoreduction of Atmospheric CO2 into Exclusive CO over Cu7Te4 Nanorods with Tellurium Vacancies

Abstract

The impact of defects on carbon dioxide (CO₂) photoreduction is not always well understood and can be inconsistent at times due to the absence of a clear model. Herein, the clear structure−property relationship between tellurium defects and CO₂ photoreduction property is clearly disclosed. As a prototype, an ideal model of Cu₇Te₄ nanorods with tunable defect concentrations is built, in which the defect type and distribution are verified by electron paramagnetic resonance spectra. Photoluminescence spectra demonstrate the presence of tellurium defects can promote carrier separation rates. In situ, Fourier transform infrared spectroscopy shows that the primary intermediate is the COOH^* group, while quasi in situ X-ray photoelectron spectroscopy confirms that Cu atoms serve as the active sites during CO₂ photoreduction. Density-functional calculations certify the reduced formation energy of the COOH^* intermediate following the introduction of tellurium defects. Consequently, the Cu₇Te₄ nanorods with more tellurium defects exhibit a carbon monoxide formation rate of 8.74 µL g⁻¹ h⁻¹ with stability of up to 400 h during photoreduction of atmospheric CO₂. This performance establishes them as one of the most durable photocatalysts reported under similar conditions to date.