Synergistic effects of CuS/TiO heterointerfaces: Enhanced cathodic CO reduction and anodic CHOH oxidation for paired electrosynthesis of formate.

The electrochemical reduction of carbon dioxide into energy-carrying compounds or value-added chemicals is of great significance for diminishing the greenhouse effect. However, it is still imperative to replace the less-value anodic oxygen evolution reaction (OER) to improve the technical economy. Herein, we firstly reported a bifunctional CuS/TiO catalyst for both anodic methanol oxidation reaction (MOR) and cathodic carbon dioxide reduction (COR). The in-built abundant CuS/TiO heterointerfaces are found to boost the COR and MOR to produce formate. Based on the unique bifunctionality of CuS/TiO, a paired electrosynthesis of formate was performed with a total Faradaic efficiency (FE) of about 170 %, in which the cathodic COR achieved a formate FE of about 70 %, and the anodic MOR exhibited an almost 100 % formate FE.