Electrochemically Reduced Graphene Oxide Supported Palladium-Cobalt Alloy Nanoparticles as Highly Efficient Electrocatalyst for Oxygen Reduction Reaction

Abstract

Pd-Co alloy nanoparticles were synthesized on electrochemically reduced graphene oxide (ErGO) for electrocatalytic oxygen reduction reaction (ORR) in alkaline media. The morphological structure, chemical composition, and crystallinity of the afforded ErGO/Pd-Co catalyst were examined by various techniques, including transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis. The Pd-Co alloy nanoparticles were evenly distributed on the ErGO sheet and had a narrow size distribution, with an average particle size of 4.25 nm. The ORR activity of the as-prepared ErGO/Pd-Co alloy catalyst was evaluated by cyclic voltammetry, linear sweep voltammetry, rotating disk electrode, and rotating ring disk electrode techniques in an alkaline electrolyte. The ErGO/Pd-Co catalyst exhibits a very high electrocatalytic activity in ORR with the mass activity more than 2.0 times of the commercial 20% Pt/C due to the synergistic catalytic effect of both ErGO and Pd-Co nanoparticles. Electrocatalytic kinetics investigation shows that, the ORR on the ErGO/Pd-Co catalyst proceeds through four electrons transferred mechanism with negligible amount of peroxide species. Moreover, the ErGO/Pd-Co shows an excellent methanol tolerance than the commercial 20% Pt/C.

Green Reduction of Waste-Battery-Derived Graphene Oxide by Jute Leaves and Its Application for the Removal of Tetracyclines from Aqueous Media

“…Figure a illustrates the FTIR spectra of GO and GrGO (before and after the adsorption of TCs). A significant strong and broad peak was observed at 3480 cm –1 , which is the stretching mode of the O–H (hydroxyl) group of GO. − The stretching mode of the CO (carbonyl group) appeared at 1724 cm –1 . − Strong stretching peaks at 1055 and 1625 cm –1 are characteristic of the aromatic CC and C–O–C (epoxy groups) functional groups of GO. − The C–H characteristic bending peak of aromatic benzene rings appeared at 860 cm –1 . − These FTIR results confirm that synthesized GO is filled with oxygen-containing functional groups such as hydroxyl, epoxy, carboxyl, and carbonyl, which suggest that recovered graphite from waste battery has been successfully oxidized. , After reduction of GO by jute leaf extract, the peak intensities of oxygenated functional groups were significantly decreased compared to the peak intensities of GO. This phenomenon suggests that GrGO contains less oxygen functionalized groups and GO is successfully reduced using jute leaf extract.…”

Ultrafast and simultaneous removal of four tetracyclines from aqueous solutions using waste material-derived graphene oxide-supported cobalt–iron magnetic nanocomposites

“…4(d) shows two peaks at 780.43 (Co 2p 3/2 ), and 796.48 eV (Co 2p 1/2 ), indicating the presence of cobalt atom as +2 oxidation state. 47 The appearance of these peaks also conrm that cobalt has been effectively deposited on the surface of GO. 48 Similarly, the Fe 2p spectra (Fig.…”

Efficient removal of ciprofloxacin from aqueous solution using Zn–C battery derived graphene oxide enhanced by hydrogen bonding, electrostatic and π-π interaction

“…Graphite is a naturally occurring solid substance consisting of sp 2 hybridized carbon atoms arranged in hexagonal lattices [ 53 , 57 ]. Graphene oxide (GO) is the oxidized derivative of graphene, which possesses numerous oxyginated functional groups [ 58 ]. The preparation of GO requires high quality graphite as a raw material, however, natural resources of graphite are limited, and its synthesis is relatively expensive [ 59 ].…”