Ag-organic coordination polymers with multi-dimensional electron transfer channels for enhancing CO2 electroreduction

Abstract

Although, electrons transfer plays an important role in achieving the electrocatalytic CO2 reduction reaction (CO2RR), it is scarce to regulate the electron transfer channels for enhancing the performance of CO2RR via rational design. Here, based on different solvothermal conditions, two metal–organic coordination polymers (MOCPs, Ag-MOCP-1 and Ag-MOCP-2) electrocatalyst for CO2RR were obtained by the same Ag ions and 5-phenyltetrazolium ligands. Single crystal X-ray diffraction showed Ag-MOCP-2 with intra-&inter-layer CH···π and π···π interactions, while Ag-MOCP-1 with intra-layer π···π interactions. The intra-&inter-layer π interactions in Ag-MOCP-2 makes it show multi-dimensional electron transfer channels, which enable Ag-MOCP-2 with higher electron conductivities and lower band gap than Ag-MOCP-1. And the Faradaic efficiency of CO for Ag-MOCP-2 with 78.3 % is higher than that for Ag-MOCP-1 with 69.1 % at −1.08 V vs RHE, and the maximum difference can reach 22 % at −1.48 V vs RHE. Based on the same central metal and organic ligands of the two MOCPs, we believe that multi-dimensional electron transfer channels make a predominant contribution for improving CO2RR performance in this work.