Facile synthesis of palladium nanodendrites supported on graphene nanoplatelets: an efficient catalyst for low overpotentials in lithium–oxygen batteries

Abstract

Morphology-controlled Pd nanodendrites were synthesized on CPC-functionalized graphene and they exhibited excellent catalytic activity towards oxygen reduction and evolution reactions.

Facile Synthesis of Composition‐Controlled Graphene‐Supported PtPd Alloy Nanocatalysts and Their Applications in Methanol Electro‐Oxidation and Lithium‐Oxygen Batteries

“…[64] Macroporous-GNP/GO (m-GNP/GO) electrodes were fabricated by using the modified vacuum-filtration method previously reported by us. [43,65] First, the aqueous PSS-GNP solution (32.5 mL, 0.1 mg mL À1 ), prepared as described above, was mixed with an aqueous GO solution (3.5 mL, 0.5 mg mL À1 )a nd aP Sd ispersion in H 2 O( 0.7 mL, 2.7 wt %). AP S/GNP/GO composite film was then obtained by vacuum filtration of the mixture through ap olyvinylidene fluoride (PVDF) filter membrane (Millipore, 0.45 mmp ore size, 47 mm diameter), and then dried in ambient air.T he m-GNP/GO electrodes were finally prepared by removing the PS particles through heating in at ube furnace at 500 8Cf or 2h under Ar.T he m-Pt x Pd y -GNP/GO electrodes (m-Pd-GNP/GO, m-Pt-GNP/GO, m-Pt 80 Pd 20 -GNP/GO, and m-Pt 40 Pd 60 -GNP/GO) were fabricated through the same procedure, but replacing GNP with Pd-GNP,P t-GNP, Pt 80 Pd 20 -GNP,and Pt 40 Pd 60 -GNP,r espectively.…”

“…[4,40] In most studies, the preparation of graphene-supported metal nanocatalysts in solution follows two steps:1 )surface functionalization of graphene, and 2) reduction of metal ions on the graphene surface. [4,[40][41][42][43][44][45][46][47] Functionalization of graphene is required to activate the inert graphene surface used for anchoring the metal nanocatalyst.M etal precursors in solution are then directly reduced on the functionalized graphene surface through chemical, thermal,o re lectrochemical methods. For example, Yang et al reported composition-controlled PtPd alloy nanoparticles supported on graphene and their composition-dependente lectrocatalytic activity toward the ORR.…”

“…Recently,o ur group also prepared morphology-controlled Pd nanodendrites supported on graphene through at wo-step synthesis in which cetylpyridinium chloride (CPC) was used to functionalize the graphene surface. [43] The positive charges on the pyridinium groups in the CPC provided anchorings ites for Pd ions through electrostatic interactions. Pd ions were then reduced with ascorbic acid to form Pd nanodendrites on the graphene surfaceinawell-distributed manner.…”

“…Graphene meets these requirements and is a promising candidate as a support material for electrocatalysts, and several studies on graphene‐supported metal nanocatalysts have been reported . In most studies, the preparation of graphene‐supported metal nanocatalysts in solution follows two steps: 1) surface functionalization of graphene, and 2) reduction of metal ions on the graphene surface . Functionalization of graphene is required to activate the inert graphene surface used for anchoring the metal nanocatalyst.…”

“…In this study, a graphene surface was functionalized with poly(diallyldimethylammonium chloride) (PDDA), and ethylene glycol was used as the reducing agent. Recently, our group also prepared morphology‐controlled Pd nanodendrites supported on graphene through a two‐step synthesis in which cetylpyridinium chloride (CPC) was used to functionalize the graphene surface . The positive charges on the pyridinium groups in the CPC provided anchoring sites for Pd ions through electrostatic interactions.…”