Functionalization Of Graphene And Its Application In Oxygen Reduction Eletrocatalysis

Fuel cell is a clean, high-efficient energy conversion device that convertsthe chemical energy from a fuel into electricity through a chemical reactionwith oxygen. Because of the high cost, scarce supply and poor durability of Pt,substantial efforts have been dedicated to improve its performance and searchfor non-noble metal catalysts (NPMC). Graphene, because of its good electronconductivity and electrochemical stability holds a great potential in the field ofelectrochemistry. Tailoring the electronic arrangement of graphene by doping isa practical strategy for producing significantly improved materials for theoxygen-reduction reaction (ORR) in fuel cells. Recent studies have proven thatthe carbon materials doped with the elements, such as N-doped carbonnanotubes (CNTs), P-doped graphite layers and B-doped CNTs, have alsoshown pronounced catalytic activity. Herein, we attempt to study graphenesdoped with other elements and their application in oxygen reductionelectrocatalysis. The main contents are as follows:(1) Phosphorus-doped graphenes were synthesized by directly annealinggraphene oxide and phosphorustriphenyl in argon. TEM and XPS tests confirmthat phosphorus has been doped into graphene successfully. The electrocatalyticperformances show that P-doped graphene is more excellent than commereialplatinum-carbon catalyst in oxygen reduction electrocatalysis activity.(2) Sulfur-doped graphenes were synthesized by directly annealinggraphene oxide and benzyl disulfide in argon. The structure of the S-graphenewas characterized through TEM, Raman and XPS. These tests prove that sulfurhas been successfully doped into graphene. The electrocatalytic performancesshow that sulfur-doped graphene is more excellent than commereialplatinum-carbon catalyst in oxygen reduction electrocatalysis activity.(3) Iodine-doped graphenes were prepared by annealing graphene oxideand iodine in argon. The structure of the I-graphene was characterized through XPS and Raman. The electrocatalytic performances show that the I-graphenecan exhibit better catalytic activity and longer-term stability than a commercialPt/C catalyst.