Heterostructure construction of covalent organic frameworks/Ti 3 C 2 -MXene for high-efficiency electrocatalytic CO 2 reduction

Covalent organic frameworks (COFs), as typical organic functional materials, have shown promising potential for application in photo/electrocatalysis, especially in the electrocatalytic CO 2 reduction reaction (CO 2 RR). COFs can ensure effective CO 2 adsorption and rapid mass transfer by virtue of controllable active sites and a large specific surface area. However, the inefficient interlayer conductivity of most COFs leads to a low electron transfer rate that restricts their practical applications. In this work, porphyrin-based covalent organic framework nanosheets (Por-COF) were vertically grown on the modified MXene surface for efficient electrocatalytic CO 2 RR. The large exposed MXene surface serves as a carrier “bridge” for dispersed COFs, which can endow heterojunctions with more active sites and fast ion transport channels. The optimal sample can exhibit superior efficient CO 2 RR performance, in which the faradaic efficiency of the CO 2 -to-CO conversion was 97.28% at −0.6 V vs. RHE, and the bias current density was −9.33 mA cm −2 at −1.0 V vs. RHE.