Fabrication of MgFe₂O₄/MoS₂ Heterostructure Nanowires for Photoelectrochemical Catalysis

Abstract

A novel one-dimensional MgFe2O4/MoS2 heterostructure has been successfully designed and fabricated. The bare MgFe2O4 was obtained as uniform nanowires through electrospinning, and MoS2 thin film appeared on the surface of MgFe2O4 after further chemical vapor deposition. The structure of the MgFe2O4/MoS2 heterostructure was systematic investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectrometry (XPS), and Raman spectra. According to electrochemical impedance spectroscopy (EIS) results, the MgFe2O4/MoS2 heterostructure showed a lower charge-transfer resistance compared with bare MgFe2O4, which indicated that the MoS2 played an important role in the enhancement of electron/hole mobility. MgFe2O4/MoS2 heterostructure can efficiently degrade tetracycline (TC), since the superoxide free-radical can be produced by sample under illumination due to the active species trapping and electron spin resonance (ESR) measurement, and the optimal photoelectrochemical degradation rate of TC can be achieved up to 92% (radiation intensity: 47 mW/cm(2), 2 h). Taking account of its unique semiconductor band gap structure, MgFe2O4/MoS2 can also be used as an photoelectrochemical anode for hydrogen production by water splitting, and the hydrogen production rate of MgFe2O4/MoS2 was 5.8 mmol/h·m(2) (radiation intensity: 47 mW/cm(2)), which is about 1.7 times that of MgFe2O4.

Magnesium ferrite nanostructures for detection of ethanol vapours - a first-principles study

“…The band gap of MgFe 2 O 4 ceramics is observed to be 1.74 eV near the gamma point (Γ). Furthermore, the observed band gap of MgFe 2 O 4 nanostructure is validated with the reported experimental work (1.90 eV [3]). Benko et al [31] reported the effect of defects on photoelectrochemical properties of MgFe 2 O 4 semiconductor and estimated the experimental band gap of 2.18 eV.…”

“…Benko et al [31] reported that magnesium ferrite has the energy band gap value of 2.18 eV. Recently, Fan et al [3] have also confirmed that the energy band gap of pristine MgFe 2 O 4 material as 1.9 eV, which supports the present work. The validation of the present study with previously reported work is a significant criterion.…”

“…Magnesium ferrite (MgFe 2 O 4 ) is one of the promi-nent spinel structured n-type semiconductor materials with direct band gap of 1.9 eV [3], which can be effectively used in various fields, including hyperthermia [4], sensor [5], metal ion removal [6], anode materials [7], azo-dye degradation [8] and photocatalysts [9]. In addition, MgFe 2 O 4 exhibits high resistivity, low dielectric and magnetic losses, hence it is a significant system in heterogeneous catalysis, sensors and adsorption [10].…”

“…Ethanol interaction on position: a) A, b) B, c) C, d) D and e) E ethanol molecules with O atom in MgFe 2 O 4 nanostructure, which is mentioned as position E.The sensing mechanism and adsorption energy of ethanol vapour molecules on MgFe 2 O 4 nanostructure can be expressed using the equations(2) and(3) as:E ad = E(MFO/Et) − E(MFO) − E(Et) + E(BSSE) (3)where E(MFO/Et) refers the energy of MgFe 2 O 4 /CH 3 CH 2 OH. The isolated energy of MgFe 2 O 4 nanostructure is represented as E(MFO) and E(Et) infers the isolated energy of ethanol molecules.…”

Fabrication of Ag3PO4/GO/NiFe2O4 composites with highly efficient and stable visible-light-driven photocatalytic degradation of rhodamine B

“…32 Moreover, ferrites overcome the technical problem of separation and reuse as they are magnetically separable. 33,34 Among the class of ferrites, nickel ferrite (NiFe 2 O 4 ) is signicant because of its excellent chemical stability, remarkable mechanical hardness, high electromagnetic performance and ferromagnetic behavior. 35 Some researchers found that ferrite semiconductors could inhibit Ag 3 PO 4 photocorrosion, according to the previous reports.…”