Interfacial Accumulation and Stability Enhancement Effects Triggered by Built-in Electric Field of SnO/LaOCl Nanofibers Boost Carbon Dioxide Electroreduction.

Constructing a built-in interfacial electric field (BIEF) is an effective approach to enhance the electrocatalysts performance, but it has been rarely demonstrated for electrochemical carbon dioxide reduction reaction (CORR) to date. Herein, for the first time, SnO/LaOCl nanofibers (NFs) with BIEF is created by electrospinning, exhibiting a high Faradaic efficiency (FE) of 100% C product (CO and HCOOH) at -0.9--1.1 V versus reversible hydrogen electrode (RHE) and a maximum FE of 90.1% at -1.2 V in H-cell, superior to the commercial SnO nanoparticles (NPs) and LaOCl NFs. SnO/LaOCl NFs also exhibit outstanding stability, maintaining negligible activity degradation even after 10 h of electrolysis. Moreover, their current density and FE are almost 400 mA cm at -2.31 V and 83.4% in flow-cell. The satisfactory CORR performance of SnO/LaOCl NFs with BIEF can be ascribed to tight interface of coupling SnO NPs and LaOCl NFs, which can induce charge redistribution, rich active sites, enhanced CO adsorption, as well as optimized Gibbs free energy of *OCHO. The work reveals that the BIEF will trigger interfacial accumulation and stability enhancement effects in promoting CORR activity and stability of SnO-based materials, providing a novel approach to develop stable and efficient CORR electrocatalysts.