An efficient photocatalytic CO2 reduction system improved by emodin as a redox mediator

Summary: To facilitate electron transfer and charge separation between multiple components in a traditional homogeneous photocatalytic system, researchers incorporated a redox mediator to relay electrons from the photosensitizer to the catalyst. In the end, a high TON and selectivity for CO₂-to-CO conversion were achieved under visible-light irradiation. In addition, the results provide a promising approach to improve the performance of homogeneous solar fuel production.

The conversion of carbon dioxide (CO₂) into renewable fuels such as CO, CH₄, CH₃OH is a sustainable approach for addressing the shortage of fossil fuels and environmental concerns such as the greenhouse effect. However, high catalytic performance and selectivity remain significant challenges for CO₂ reduction. Transition metal-based molecular catalysts with high activity and structural tunability, which address the abovementioned concerns, have attracted considerable attention. However, a traditional homogeneous photocatalytic system for CO₂ reduction normally suffers from slow electron transfer and poor charge separation between multi-components.

A study published in the KeAi journal Green Chemical Engineering, has incorporated an organic redox mediator, emodin, into a multi-component photocatalytic system. Emodin can act as an electron relay, which effectively shuttles electrons from the photosensitizer to the catalyst for CO₂ reduction.