Electronic Structure Engineering of 2D Carbon Nanosheets by Evolutionary Nitrogen Modulation for Synergizing CO2 Electroreduction

In this work, we present a supramolecular template-derived synthesis approach combined with a carbon electronic structure tailoring strategy to prepare N-doped carbon (NC) nanosheets with delicately tuned nitrogen dopant levels and types for selective CO2 electrocatalytic reduction. By this method, the NC nanosheets are able to electrochemically reduce CO2 to CO with an unprecedentedly superior Faradaic efficiency (FE) of 92% at a moderate overpotential as low as −0.36 V and showed great long-term stability with a remnant FECO around 85% after 10 h of electrolysis. The improved performance of NC nanosheets is mainly attributed to the synergetic effect of the electronic interaction of pyridinic nitrogen with adjacent C atoms in the interfacial nanoregime and the concomitant pore structure, high conductivity, as well as surface wettability. The capability to modulate the catalytic site electron densities opens up further opportunities for the rational re-engineering of carbon-based catalysts with accelerated electrocatalytic activity toward renewable energy applications and beyond.