Photochemical reduction of CO₂ into CO coupling with triethanolamine decomposition

In this work, the impacts of triethanolamine (TEOA) on the performance of photochemical CO₂ reduction were investigated in a simple homogeneous system. We demonstrates that CO₂ can be converted into CO coupling with the decomposition of triethanolamine in TEOA aqueous solution without other additives under light irradiation. About 7.5 μmol CO product is achieved within 7 h with a maximum apparent quantum yield (AQY) of 0.086% at 254 nm. The isotope labelling experiment confirms that CO product originates from the reduction of CO₂ rather than the decomposition of TEOA. In addition, the photochemical system exhibits excellent stability, no obvious inactivation is observed during long-term photochemical CO₂ reduction reaction. This work provides a deep understanding of the effects of TEOA on the performance of photocatalytic CO₂ reduction. Upon utilizing TEOA as a sacrificial electron donor in photocatalytic system, the contribution of TEOA must be considered once evaluating the catalytic activity of catalysts.