Rapid Synthesis of Mesoporous, Nano‐Sized MgCr₂O₄ and Its Catalytic Properties

Abstract

Monophasic MgCr2O4 has been synthesized by calcining the gel formed by the addition of epoxide to an ethanolic solution containing MgCl2·6H2O and CrCl3·6H2O. The sample has been characterized by a variety of analytical techniques including powder X‐ray diffraction (PXRD), FT‐IR, Raman, UV–Visible spectroscopy, transmission electron microscopy, and magnetic measurements at room temperature. Calcining the xerogel at 500°C and 700°C for 2 h yielded MgCr2O4 (yield of almost 61% by weight). BET surface area of 33.95 m2/g with an average pore diameter of 28.45 nm was obtained for the sample after calcination at 700°C. Square facets of the cubic spinel structure were observed in TEM images with an average crystallite diameter of 18 nm. HR‐TEM experiments and SAED measurements confirmed the spinel structure and negated the presence of other phases. The presence of MO4 tetrahedral and MO6 octahedral units in MgCr2O4 has also been evidenced from FTIR and Raman spectra. The sample showed paramagnetic behavior at room temperature with μeff of 3.54 B.M suggesting the presence of Cr in III oxidation state. Its use as an efficient catalyst for the oxidative degradation of Xylenol Orange (XO) and the photo degradation of Rhodamine‐6G (Rh‐6G) dyes have been demonstrated as these dye molecules are environmental pollutants.

Prediction of novel X 2 ZnZ 4 (X = Sc, Y; Z = S, Se) spinels materials for renewable energy applications

“…28 Thus, they are suitable candidates for optoelectronic devices and have several other applications in the field of geophysics, magnetism, catalysis, and environment. [29][30][31][32] Thio-spinels also have applications in the field of defect engineering study while applying pressure in definite ways. 33 Particularly, materials consist of three different elements/ions can simply be altered for desirable applications.…”

Topotactic Transformation of Solvated MgCr-LDH Nanosheets to Highly Efficient Porous MgO/MgCr2O4Nanocomposite for Photocatalytic H2Evolution

“…25 Furthermore, there is no report on photocatalytic application of MgCr 2 O 4 up to now apart from the report about the oxidative degradation of Xylenol Orange and photodegradation of Rhodamine-6G dyes as environmental pollutants by Nagarajan et al in 2015. 18 Besides the photocatalysis using MgCr 2 O 4 , systematic study and mechanistic approach toward clean H 2 production with high efficiency under visible light irradiation is still needed. Therefore, there is an urgent demand but still significant challenge to rationally design MgCr 2 O 4 NPs with optimized performance by tailoring the structure, morphology, and surface or hybridizing with other nanostructured porous metal oxide to form hybrid nanostructure materials.…”

Nanostructured biogel templated synthesis of Fe3O4 nanoparticles and its application for catalytic degradation of xylenol orange

“…7 Various kinds of magnetic nanoparticles, such as MgCr 2 O 4 , Mn x Fe 1Àx O and Fe 3 O 4 nanoparticles, have been applied to catalyze the oxidative or photo degradation of pollutants in water, such as dyes, phenols, and bacteria. 6,[8][9][10] Fe 3 O 4 nanoparticles are the most commonly used magnetic nanomaterials, and they are usually prepared through thermal decomposition, solvothermal reaction, co-precipitation and so on. [11][12][13][14] However, due to their inherent magnetic interactions and high surface energies, the aggregation of Fe 3 O 4 nanoparticles is inevitable in many cases, which leads to their wide size distributions, small surface areas, and hence low catalytic efficiencies.…”