Boosting CO2 electroreduction over layered zeolitic imidazolate frameworks decorated with Ag2O nanoparticles

Abstract

Silver (Ag) is one of the widely investigated catalysts for CO₂ electroreduction. To improve the faradaic efficiency for CO production over Ag catalysts, many efforts have been devoted to tuning the size and morphology of Ag catalysts, using Ag-containing complex compounds or ionic liquid electrolyte. Herein, we report a strategy to enhance CO₂ electroreduction by constructing a Ag₂O/layered zeolitic imidazolate framework (ZIF) composite structure via one-pot hydrothermal treatment of ZIF-7 nanoparticles (NPs) in AgNO₃ aqueous solution. The Ag₂O/layered ZIF shows much higher CO faradaic efficiency and current density than the layered ZIF or Ag/C alone. The performance improvement in CO₂ electroreduction over the Ag₂O/layered ZIF is probably attributed to the synergistic effect between Ag₂O NPs and the layered ZIF, as well as facilitated mass transport due to the high specific surface area of the Ag₂O/layered ZIF.