Hybrid Nanostructure of Sputter Decorated Nanodots of Ag₂O/AgO over Flower-like Mn–Co–Cu Ternary Metal Oxide for Electrocatalytic Oxygen Evolution Reaction

Abstract

Hybrid nanostructures of quaternary-composite metal oxide catalyst consisting of silver oxide nanodots over flower-like nanostructures of ternary metal oxide (MnCoCuO x ) were synthesized by a hydrothermal method, followed by DC magnetron sputtering. Multimetal ions in spinel structures are efficient OER catalysts as they have large number of active sites, enhancing the electron transfer process. The sputter decorated silver oxide nanodots enhances the electrochemically active surface area (ECSA) of the electrode, which further enhances the OER performance. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), and Raman spectroscopy were used to validate the structure and composition of synthesized material. Oxygen evolution reaction (OER) activities of the synthesized catalysts were investigated by conducting linear scan voltammetry (LSV) at sweeping rate of 5 mV/s, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge−discharge (GCD). Quaternary-composite metal oxide catalysts were synthesized at various plasma powers, keeping other sputtering parameters fix. Silver oxide nanodots sputter decorated at 45 W over MnCoCuO x, showed the best catalytic properties for OER, having an overpotential of 83 mV via anodic scan and 110 mV via cathodic scan, Tafel slope of 65 mVdec −1 , ECSA of 826 cm 2 , mass activity of 143.7 A g −1 , and a turn over frequency (TOF) of 0.039 s −1 . The symmetric device fabricated using the best performing electrode as cathode and anode displayed efficient water splitting activity, achieving a current density of 10 mA/cm 2 at 1.37 V vs RHE, which is close to thermodynamic value of 1.23 V.

Cooperative Design of the Ag3PO4/NH2-MIL-88B (Fe/Co) Heterojunction Integrated with Conductive Polypyrrole for Advanced Photocatalytic Water Purification

“…There were noticeable differences in the Ag 3d spectrum from the photocatalytic fabrics (Figure b). In Ag@f, the Ag 3d 5/2 peak was deconvoluted into AgO at 366.1 eV and Ag 2 O at 367.3 eV, while the Ag 3d 3/2 peak was deconvoluted into AgO at 372.0 eV and Ag 2 O at 373.6 eV. − The deconvolution of the Ag 3d peak to AgO and Ag 2 O peaks appeared similarly for Ag/MIL@f and Ag/PPy/MIL@f. Also, the peak ratio of Ag 2 O/AgO in Ag/MIL@f and Ag/PPy/MIL@f increased compared to that of Ag@f. Such changes in the binding energy and peak ratio evince the chemical interactions between Ag 3 PO 4 and MIL as a result of the successful construction of the heterojunction . For Ag/PPy/MIL@f, new peaks for the reduced form of Ag metal (Ag 0 ) appeared at 372.4 and 374.4 eV, which may result from the enhanced charge transfer ability by the heterojunction .…”

Nanoflowers of Ternary Cobalt–Copper–Manganese Oxide as an Efficient Electrocatalyst for Oxygen Evolution Reaction

“…1-1155), [17] with peaks at 2θ = 44.5, 61.4, and 76.4 (in degrees), [32][33][34] which correspond to (400), (511), and (533) crystal planes. [35] The XRD pattern of CCM is well matched with the cubic spinel phase of CuCoMnO x (ICDD 47-0324), [36][37][38][39] with peaks located at 2θ ). [40] The XRD pattern of CCM appears to be a combination of CC and CM XRD patterns.…”

“…1-1155),[17] with peaks at 2θ = 44.5, 61.4, and 76.4 (in degrees),[32][33][34] which correspond to (400), (511), and (533) crystal planes [35]. The XRD pattern of CCM is well matched with the cubic spinel phase of CuCoMnO x (ICDD 47-0324),[36][37][38][39] with peaks located at 2θ = 35.5, 38.6, 44.5, 61.4, and 76.4 (in degrees) that correspond to (311), (222), (400), (511), and (533) crystal. The peak shown with # corresponds to Cu 2 O impurity in CCM and CC patterns at 36.5, 43.2, and 74.3 peak positions assigned to (111), (200), and (311) crystal planes (JCPDS file no.…”

High-Performance Supercapacitor with a Hybrid Nanostructure of Sputter-Decorated AgxO over Co–Mn–Cu Ternary Metal Oxide

“…The XRD pattern matches the cubic phase of Ag 2 O (JCPDS card number 76-1393). 46 The (132) crystal plane corresponds to the peak at 44.3°matching with the AgO phase, which indicates multiple oxide phases of silver oxide.…”