Photocatalytic Activity of Magnetic Nano-β-FeOOH/Fe3O4/Biochar Composites for the Enhanced Degradation of Methyl Orange Under Visible Light

Abstract

A novel nano-β-FeOOH/Fe3O4/biochar composite with enhanced photocatalytic performance and superparamagnetism was successfully fabricated via an environmentally friendly one-step method. The structural properties of the prepared composite were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy, and a vibrating sample magnetometer. The XPS spectrum of the as-prepared composites confirmed the presence of Fe-O-C bonds between β-FeOOH and biochar, which could be conducive to transfer photo-generated electrons. UV-vis spectroscopy confirmed the existence of an electron–hole connection between β-FeOOH and biochar, which promoted the rapid interface transfer of photogenerated electrons from β-FeOOH to biochar. These novel structures could enhance the response of biochar to accelerate the photoelectrons under visible light for more free radicals. Electron spin resonance analysis and free radical quenching experiments showed that •OH was the primary active species in the photodegradation process of methyl orange by nano-β-FeOOH/Fe3O4/biochar. In the synergistic photocatalytic system, β-FeOOH/Fe3O4/biochar exhibited excellent catalytic activity for the degradation of azo dye (methyl orange), which is 2.03 times higher than that of the original biochar, while the surface area decreased from 1424.82 to 790.66 m2·g−1. Furthermore, β-FeOOH/Fe3O4/biochar maintained a stable structure and at least 98% catalytic activity after reuse, and it was easy to separate due to its superparamagnetism. This work highlights the enhanced photocatalytic performance of β-FeOOH/Fe3O4/biochar material, which can be used in azo dye wastewater treatment.

Manganese dioxide-coated biocarbon for integrated adsorption-photocatalytic degradation of formaldehyde in indoor conditions

“…The increase in the ID/IG ratio suggested an increase in the defect degree, which can be attributed to the formation of MnO 2 particle clusters within the BC structure. Similarly, a prior study [ 40 ] reported an ID/IG ratio increase when β-FeOOH/Fe 3 O 4 nanoparticles were added to BC. They assigned this increase to the reduction in the carbon sp 2 domain and justified that the β-FeOOH/Fe 3 O 4 nanoparticles formed and grew on the graphitic structure of the material.…”

EDTA–Fe2+ Complex-Functionalized Fe3O4 Nanozyme as Tyrosine Hydroxylase Mimics for the Production of l-DOPA

“…XPS demonstrated that Fe, C, O, and N elements were present on the Fe 3 O 4 @EDTA–Fe 2+ nanoparticle surface (Figure B). The typical doublet photoelectron peaks of Fe at 724.40 and 710.9 eV in the XPS profile of the pristine nanoparticles could be assigned to the Fe 2p 1/2 and Fe 2p 3/2 components, respectively (Figure C) . Each peak could be sud-divided into two peaks, which accounted for the simultaneous contribution of Fe 2+ and Fe 3+ .…”

“…The typical doublet photoelectron peaks of Fe at 724.40 and 710.9 eV in the XPS profile of the pristine nanoparticles could be assigned to the Fe 2p 1/2 and Fe 2p 3/2 components, respectively (Figure 2C). 23 Each peak could be sud-divided into two peaks, which accounted for the simultaneous contribution of Fe 2+ and Fe 3+ . 24 In the C 1s spectrum, the increase in the relative content of C−O and O− CO in Fe 3 O 4 @EDTA and Fe 3 O 4 @EDTA−Fe 2+ compared to that in the pristine Fe 3 O 4 nanoparticles could be assigned to the carboxyl group, which confirmed successful formation of the EDTA layer on the surface of the nanoparticles (Figure S2A and Table S1).…”

Green algae Ulva lactuca-derived biochar-sulfur improves the adsorption of methylene blue from water

“…Green algae, as source material for biochar, represents a sustainable and renewable resource, as it can be cultivated in various water bodies, including those unsuitable for other uses 37 – 42 . Algae-based biochar, especially when modified, can have a high surface area and porosity, making it highly effective for adsorbing pollutants, including heavy metals, dyes, and organic compounds from wastewater 28 , 43 – 45 . Moreover, it emphasizes that the presence of N-functional groups in algae-based biochar improved its surface chemistry and adsorption capacity 46 .…”