Facile synthesis of electrospun MFe₂O₄(M = Co, Ni, Cu, Mn) spinel nanofibers with excellent electrocatalytic properties for oxygen evolution and hydrogen peroxide reduction

Abstract

Designing and preparing porous transition metal ferrites without using any template, shape-directing agent, and surfactant is a challenge. Herein, heterojunction MFe2O4 (M = Co, Ni, Cu, Mn) nanofiber (NF) based films with three-dimensional configurations were synthesized by electrospinning and the subsequent thermal treatment processes. Characterization results indeed show the 3D net-like textural structures of the electrospun spinel-type MFe2O4 NFs. In particular, the resulting MFe2O4 NFs have lengths up to several dozens of micrometers with an average diameter size of about 150 nm and possess abundant micro/meso/macropores on both the surface and within the films. The hierarchically porous structures and high surface areas of these MFe2O4 NFs (for example, the CoFe2O4 NFs possess a larger BET specific surface area (61.48 m(2) g(-1)) than those of the CoFe2O4 NPs (5.93 m(2) g(-1))) can afford accessible transport channels for effectively decreasing the mass transport resistances, enhancing the electrical conductivity, and increasing the density and reactivity of the exposed catalytic active sites. All these advantages will be responsible for the better electrocatalytic performances of these MFe2O4 NFs compared with their structural isomers (i.e. the MFe2O4 NPs) for the oxygen evolution reaction (OER) and H2O2 reduction in alkaline solution. Meanwhile, both the OER and H2O2 reduction catalytic activities for these MFe2O4 NFs obey the order of CoFe2O4 NFs > CuFe2O4 NFs > NiFe2O4 NFs > MnFe2O4 NFs > Fe2O3 NFs. The CoFe2O4 NFs represent a new class of highly efficient non-noble-metal catalysts for both OER and H2O2 reduction/detection in alkaline media.

Room-Temperature Synthesis FeNiCo Layered Double Hydroxide as an Excellent Electrochemical Water Oxidation Catalyst

“…33 In the highresolution spectrum of Co 2p ( Figure 3C, blue and magenta lines), the binding energy of the peaks at 780.96 eV and 783.22 eV are attributed to Co 2p 3/2 , indicating the presence of Co (II) and Co (III) species in FeNiCo LDH. 34 It's worth noting that besides the peak for Fe (III) (710.78 eV, Figure 3D, blue line), another peak appeared at binding energy of 712.78 eV ( Figure 3D, magenta line), suggesting the existence of Fe (IV) in the material. 35 Boettcher et al 36 demonstrated that Fe affects the local electronic structure of NiOOH and may serve as the active site.…”

Recent Progress on Multimetal Oxide Catalysts for the Oxygen Evolution Reaction

“…The authors suggested that the role of Fe in OER activity is to www.advenergymat.de modulate the porosity of the material and change the electronic structure of the material. [135] …”

Facile synthesis of electrospinning Mn2O3-Fe2O3 loaded carbon fibers for electrocatalysis of hydrogen peroxide reduction and hydrazine oxidation

“…Mn-based catalyst is beneficial to keep 3D net-like structure. The distinctive structure may bring more advantages, such as large specific surface area and more exposed active sites for reactions [36,46]. EDS was also conducted to further confirm the composition of Mn 2 O 3 -Fe 2 O 3 /CFs (3:1).…”

“…Moreover, metal salts/polymer precursor fibers which are prepared via electrospinning may be converted into metal oxides loaded CFs after the thermal treatment in air. The films assembled by the metal oxides loaded CFs possess large specific surface area, high flexibility, massive exposed active sites and excellent conductivity to facilitate charge transfer and mass transfer [46,47].…”