Facile Preparation of Porous Carbon Nanosheets without Template and Their Excellent Electrocatalytic Property.

A novel porous carbon nanosheet was successfully fabricated by a one-step annealing process with folic acid as the carbon source in the absence of any other reagents or templates. The product exhibited a large specific surface area and good porosity. Meanwhile, the carbon nanosheets as a metal-free catalyst showed a high electrocatalytic activity toward the oxygen reduction reaction (ORR) in alkaline solution, including superior onset and reduction potentials as well as a nearly four-electron pathway.