Synthesis of nanostructured pirochromite magnesium chromate with egg shell membrane template

Abstract

In this work, we report on the use of fresh and boiled egg shell membrane as bio-templates in the coprecipitation of pirochromite. The structure evolution, microstructure and optical properties of the ESM templated MgCr 2 O 4 nanomaterial were studied by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, Energy dispersive X-ray spectroscopy, elemental mapping and UV-Vis-NIR spectrophotometry. The annealing of the untemplated and templated co-precipitated MgCr 2 O 4 powders at 1000°C for 4 h produced single phased nanostructured material with spinel cubic crystal structure. The FTIR results showed slight variations in the band positions m 1 and m 2 which are attributed to the change in the microstructure due to the introduction of ESM in the preparation of MgCr 2 O 4 . The morphologies and average crystallite size of the annealed MgCr 2 O 4 nanocrystalline powders depended on the type of the template. 3D hierarchical flake-like and mesh like structures were observed. The annealed MgCr 2 O 4 nanocrystalline powders have shown excitonic absorptions in the visible range 300-500 nm due to the transitions that took place from the O-2p level to the Cr-3d level. The optical band gap energies were found to be 3.68-3.71 eV for the direct band gap and 3.30-3.37 eV for the indirect band gap. This could make these MgCr 2 O 4 nanocrystalline powders possible photocatalysts in the visible range 300-500 nm.

Electrospun Polyvinylidene Fluoride–Magnesiochromite Nanofiber-Based Piezoelectric Nanogenerator for Energy Harvesting Applications

“…In addition, the ESM was used as a template in the synthesis of size-controlled spinel-type nanomaterials with ordered microporous structures. Because of their specific size and morphology, template-assisted nanomaterials have become increasingly popular. − Considering the above advantages of the ESM, a synthesis route of producing magnesiochromite nanocrystalline powder (MgCr 2 O 4 ) with the controlled size and morphology using the ESM as a template was proposed in this work. Magnesiochromite is a class of spinel compounds with a cubic crystal structure and the Fd 3 m space group.…”

“…The synthesis of MNC was done following the procedure given elsewhere. 44 In brief, chicken eggs were boiled, and their inner ESM were removed, washed with acetone and DI (deionized) water thoroughly, and dried at 60 °C. Nitrate solutions were prepared in DI water, and 1 M NaOH solution was added slowly.…”

Green nanoceramic pigments based on cobalt chromite doped with Al: Synthesis, characterisation and colour performance

“…The focus of recent research has been on chemical synthesis, in which the powders are synthesised in liquid systems. Thus, several authors have proposed different synthesis routes, such as hydrothermal processes [20], coprecipitation [21], microemulsion [22], combustion [23][24][25] and sol-gel [26][27][28]. Amongst these methods is the polymerisable complex process using the polymeric precursor, in which the metal cations are homogeneously distributed within the polymer chain.…”