General Flame Approach to Chainlike MFe₂O₄ Spinel (M = Cu, Ni, Co, Zn) Nanoaggregates for Reduction of Nitroaromatic Compounds

Abstract

Unique chain-like MFe 2 O 4 (M = Cu, Ni, Co, and Zn) nanoaggregates (NAs) have been prepared by facile flame spray pyrolysis of nitrates-ethanol precursor. The synthesized MFe 2 O 4 are composed of primary nanocrystallites mainly ranging from 8 to 20 nm and show uniform aggregations with size of 200 -400 nm. As heterogeneous catalysts, it is clearly noted that CuFe 2 O 4 NAs have the highest catalytic activity for the reduction of nitroaromatic compounds compared to NiFe 2 O 4 , CoFe 2 O 4 , and ZnFe 2 O 4 . The highest rate constant of 36.17 min -1 g -1 is achieved at a low catalyst usage (10 µL, 0.2 mg mL -1 ). The remarkably enhanced catalytic performance of CuFe 2 O 4 NAs is mainly attributed to the promoted electrons transfer on Cu 2+ active sites, which is facilitated by unique spinel structures and chain-like aggregates morphology. It is demonstrated that flame spray pyrolysis technique is an effective route to produce the binary or complex oxides for potential industrial use.

Molecular-Level Understanding of Selectively Photocatalytic Degradation of Ammonia via Copper Ferrite/N-Doped Graphene Catalyst under Visible Near-Infrared Irradiation

“…These diffraction peaks are indexed to Bragg planes (220), (311), (511) and (440), respectively. CuFe 2 O 4 is the major crystal phase, which is in good agreement with JCPDS 25-0283 for the cubic spinel CuFe 2 O 4 [27,28]. Peaks at 2θ = 32.90 • [plane 110] and 39.11 • [plane 111] suggests a small fraction of CuO.…”

“…The high-resolution transmission electron microscopy (HRTEM) image displayed the lattice fringes. The d-spacing value between the adjacent lattice fringes is 0.25 nm ( Figure 3C), which is characteristic of (211) spinel planes [27,28]. The size of CuFe2O4 crystals looked uniform; the diameter of most crystal particles is distributed about 25-30 nm, which is in the scope of the average particle size of CuFe2O4 crystals that was estimated by XRD.…”

Reduced Graphene Oxide – Zinc Sulfide Composite for Solar Light Responsive Photo Current Generation and Photocatalytic 4‐Nitrophenol Reduction

“…Recently, RGO‐based composite have been utilized for photocatalytic degradation of different water pollutants . The photocatalytic reduction of 4‐NP in presence ofNaBH 4 is a standard protocol to probe the catalytic performance of different semiconducting catalyst . The UV‐vis absorption spectra of 4‐NP in aqueous solution shows characteristics absorption peak at about 317 nm.…”

“…The UV‐vis absorption spectra of 4‐NP in aqueous solution shows characteristics absorption peak at about 317 nm. Upon addition of NaBH 4 , peak red shifted to 400 nm owing to the formation of 4‐nitrophenolate ion in alkali medium [Figure S4 A, SI] . Accordingly, the color of the solution changes from pale yellow to bright yellow.…”

Gold nanoparticles decorated silicate sol-gel matrix embedded reduced graphene oxide and manganese ferrite nanocomposite-materials-modified electrode for glucose sensor application

“…Manganese ferrite (MnFe 2 O 4 ), an eco-friendly material with favorable capacitive characteristics, is a suitable material for a wide range of applications such as Li-ion batteries, heterogeneous catalysts, gas sensors, etc. [1][2][3][4][5][6] Though the ferrites are advantageous in the development of catalysis, certain limitations including defects, mechanical instability, poor electronic conductivity significantly impede them from wide applications in catalysis with high sensitivity, fast response and reliability. 7 Considering the aforesaid issues, it is important to enhance the charge transport ability of ferrites by coupling them with highly conducting materials, such as single and multi-walled carbon nanotubes (CNTs), * For correspondence Electronic supplementary material: The online version of this article (https:// doi.org/ 10.1007/ s12039-019-1611-z) contains supplementary material, which is available to authorized users.…”