Magnetization and optical bandgap of Cu-Mn vanadate-oxide mixed phase nanostructures

Abstract

Copper vanadate (CV) and manganese vanadate (MV) exhibit magnetic and optical properties that have drawn the attention. Due to CV polymorphism and phase multiplicity, CV is common to exist as mixed phases. In this study, nanostructures of mixed-phase CVs mixed with MV were synthesized hydrothermally followed by calcination at 400 °C, with Mn mole fractions 0.0, 0.4, 0.6, 1.0. The uncalcined and calcined Mn-Cu vanadates (MCVs) were investigated by XRD, SEM, TEM, FT-IR, EDX, ICP-AES, TGA, DTA, DSC, BET, XPS, and VSM. XRD analysis shows co-existence of multi-phase CVs with MnV2O6 and V oxides. Electron micrographs show nanostructures of multiple morphologies (rods, cubes, sheets, and irregular). As Mn content increased in the MCVs, their thermal stability increased, optical bandgap (Eg) declined from 2.46 to 1.60 eV, and magnetism diverted from the superparamagnetic-like to paramagnetic (Hc from 1362 to 69 G and Mr/Ms from 0.430 to 0.003). Magnetism parameters of calcined MCVs were more labile to Mn content variation compared to the uncalcined MCV counterparts. Graphical Abstract

Structural, optical, and dielectric characteristics of chitosan/hydroxypropyl cellulose‐modified copper vanadate nanoparticles

“…Additionally, an absorption band observed at 1616 cm −1 in the spectra can be attributed to the vibrational modes of various chemical species, including water and hydroxyl groups 36 . The band at 900 cm −1 corresponds to the v 1 (VO 3 ) symmetric vibrational stretching, while the bands at 844, 800, and 746 cm −1 are related to v 3 (VO 3 ) antisymmetric vibrational stretching 36,37 . The bands at 966, 563, and 460 cm −1 are believed to be related to δ CuOH deformation vibrations and v CuOH stretching vibrations in volborthite 36,38,39 .…”

“…36 The band at 900 cm À1 corresponds to the v 1 (VO 3 ) symmetric vibrational stretching, while the bands at 844, 800, and 746 cm À1 are related to v 3 (VO 3 ) antisymmetric vibrational stretching. 36,37 The bands at 966, 563, and 460 cm À1 are believed to be related to δCu OH deformation vibrations and vCu OH stretching vibrations in volborthite. 36,38,39 Additionally, the bands seen at 1407 and 1995 cm À1 result from overtone and/or combination bands.…”

Ultrasound - assisted synthesized multi-phase copper vanadate (Cu 3 V 2 O 8 /Cu 2 V 2 O 7 /Cu 0.4 V 2 O 5 ) shape-controlled nanoparticles as electrode material for energy storage applications

“…In this regard, vanadium compounds have become essential for various applications due to their distinct chemical and physical characteristics [5,6].Copper vanadate stands out as an intriguing inorganic material with noteworthy characteristics, such as photo catalysis, electrochemical sensing, the splitting of water, and electrochemical in nature as well as photochemical reactions storage and conversion abilities, in contrast to other vanadate structures like BiVO4 [7,8], Zn 3 (VO 4 ) [9], and Cr 2 (VO 4 ) [10] The compelling attributes of copper vanadate underscore its signi cance in advancing sustainable and versatile applications. [11][12][13].…”