Magnetized Biochar as a Gold Nanocatalyst Support for p-Nitrophenol Reduction

Abstract

The biomass use is of considerable ecological and economical interest and here, biochar, a byproduct of biomass carbonization, is magnetized with Fe3O4 for its use as gold nanoparticle (NP) support towards catalysis of p-nitrophenol (4-NP) reduction. Biochar was synthesized from coffee straw biomass via pyrolysis, while magnetite functionalization was obtained using the precipitation method. The magnetite was identified by X-ray diffraction (XRD). The material had a specific surface area of 30 m2 g-1 and a zero point charge of 7.5. The gold NPs were deposited via reduction with NaBH4, which yielded Au and Fe3O4 NP of 4.61 and 10.9 nm, respectively. The materials were applied in the 4-NP reduction, with a rate constant kapp = (1.2 ± 0.2) × 10-2 s-1, and a synergistic effect between Au and Fe3O4 NPs was observed. Remarkably, comparison with graphene oxide to which biochar resembles showed similar behavior, and the material was reused in several catalytic cycles.

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

“…Based on the aforementioned features, biochar has very excellent performances in a variety of study areas, including soil enhancement, recycling of agricultural waste, adsorption, reducing climate change, and conserving water. 7–16…”

“…Based on the aforementioned features, biochar has very excellent performances in a variety of study areas, including soil enhancement, recycling of agricultural waste, adsorption, reducing climate change, and conserving water. [7][8][9][10][11][12][13][14][15][16] To establish low-cost and sustainable procedures for organic syntheses, heterogeneous catalysts are important. In comparison to conventional organic or inorganic homogeneous catalysts, the key benets of these catalysts are the ability to recycle and reuse catalytic materials, high surface area, easy control, low toxicity, simple separation, thermal stability, production of the desired products, and prevention of by-product formation.…”