Characterization of magnetic biochar amended with silicon dioxide prepared at high temperature calcination

Abstract

Calcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD) analysis revealed elimination of Fe 3 O 4 peaks under nitrogen calcination and formation of Fe 3 Si and iron as major constituents of magnetic biochar-SiO 2 composite, which demonstrated its superparamagnetic behavior (>80 Am 2 ·kg −1 ) comparable to magnetic biochar. Thermogravimetric analysis (TGA) revealed that both calcined samples generated higher residual mass (>96 %) and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR) was more obvious and the elimination of H-O-H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM) images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.

Greener design and characterization of biochar/Fe3O4@SiO2–Ag magnetic nanocomposite as efficient catalyst for synthesis of bioactive benzylpyrazolyl coumarin derivatives

“…Modied chemical coprecipitation method was used to prepare the dried Eucalyptus globulus bark biochar with Fe 3 O 4 to synthesis of biochar/Fe 3 O 4 composite, also known as magnetic biochar (MB). 18,43,44 5.0 g of prepared dried Eucalyptus globulus bark biochar and 3.0 g FeSO 4 $7H 2 O were mixed in 250 ml distilled water with constant stirring at 80 °C for 1 h. To obtain an iron hydroxide precipitate, freshly prepared hot NaOH solution was added drop-by-drop until the medium's pH was reached between 9 and 11. The resulting mixture was stirred for 1 hour and le at room temperature for 24 hours.…”

Advances in preparation, application in contaminant removal, and environmental risks of biochar-based catalysts: a review

“…Calcination is one of the most common methods for preparing biochar based-catalysts, by which two or multifarious solid phase matters are closely bound together to achieve composite multi-functionalization. Compared with pyrolysis, calcination could increase the hardness of materials, prevent their breakage, and change material textural and mineralogical characteristics (Baig et al 2016). Just as its name implies, the temperature, gas phase composition, and thermal stability of the compound significantly affect the calcination process.…”