Efficient Heterogeneous Catalyst For Degradation Research Articles

Cobalt-doped Graphene-supported Nanoscale Zero-valent Iron: Removal of Rhodamine B solution and mechanistic study

nZVI materials loaded on GO have been applied to the treatment of difficult-to-degrade organics due to their higher electron transfer rate. However, cobalt doping of GO/nZVI composites and the effect of the doped materials on difficult-to-degrade organics are not known. In this work, Cobalt-doped Graphene-supported nanoscale Zero-valent Iron (GO/nZVI-Co) was successfully synthesized via the liquid-phase reduction-suspension self-assembly method, which was composited with theoretical mass ratio of GO:nZVI:Co = 1:2:0.08. And GO/nZVI-Co was used as efficient heterogeneous catalyst for degradation of Rhodamine B (RhB) via H2O2. Characterization results show that nZVI and Co particles were successfully loaded on GO nanosheets increasing the dispersibility of particles. Under the optimal reaction conditions(the mass ratio of GO: nZVI = 1:2 and Co doping is less than 1/5), the RhB degradation rate was as high as 98.28 %. The degradation pathways of GO/nZVI-Co-HP system could better explained by the secondary kinetic model and GC–MS spectru. The main effect of cobalt doping in the GO/nZVI-Co-HP system is to increase the adsorption properties of the material on H2O2, and this facilitates the contact reaction of nZVI with H2O2. In this study, a GO/nZVI-Co material with improved electron transfer efficiency was prepared and its removal mechanism of pollutants was elucidated to provide relevant theoretical support for the treatment of difficult-to-degrade wastewater.

Sulfur or nitrogen-doped rGO supported Fe-Mn bimetal – organic frameworks composite as an efficient heterogeneous catalyst for degradation of sulfamethazine via peroxydisulfate activation

In this work, sulfur/nitrogen modified reduced graphene oxide (S/N-rGO) was employed as both electron shuttle and support to fabricate Fe-Mn bimetallic organic framework@S/N-rGO hybrids (BOF@S/N-rGO) via a facile two-step solvothermal route. Compared with the transition metal ions (Fe2+/Mn2+), the classical metal oxide catalyst (Fe2O3 and Fe3O4) and nano zero-valent iron (nZVI), BOF@S/N-rGO catalyst can more effectively activate peroxydisulfate (PDS) with ultra-low concentration (0.05 mM) to degrade sulfamethazine (SMT). Quenching experiments, electron paramagnetic resonance (EPR) measurement and linear sweep voltammetry (LSV) showed that the activation pathways of PDS between the two catalysts were different. In BOF@N-rGO+PDS system, the degradation of SMT was mainly attributed to the oxidation of radicals including SO4•− and •OH, especially SO4•− . However, in BOF@S-rGO+PDS system, in addition to the radical pathway, there are also non-radical pathways, namely 1O2 and direct electron transfer. Furthermore, the applicability of BOF@S/N-rGO used in the PDS-mediated advanced oxidation processes (AOPs) was systematically investigated in terms of the effects of operating parameters and coexisting substance (anions and humic acid (HA)), the degradation of other pollutants, as well as the stability and reusability of the catalyst. This study proved that BOF@S/N-rGO was a promising activator of PDS with ultra-low concentration for the degradation of SMT.

Sulfur or Nitrogen-Doped Rgo Supported Fe-Mn Bimetal–Organic Frameworks Composite as an Efficient Heterogeneous Catalyst for Degradation of Sulfamethazine

Sulfur or Nitrogen-Doped Rgo Supported Fe-Mn Bimetal–Organic Frameworks Composite as an Efficient Heterogeneous Catalyst for Degradation of Sulfamethazine

Co3O4/GO catalyst as efficient heterogeneous catalyst for degradation of wastewater containing polyacrylamide(PAM)

Aiming at the produced waster containing polyacrylamide(PAM), the heterogeneous Co3O4-GO/PMS system was selected to degrade PAM in this paper. The characteristic of Co3O4/GO are studied. The degradation experiment shows that Co3O4/GO was successfully prepared and exhibited satisfactory degradation efficiency. The removal efficiency can exceed 99.7% within 90 ​min. Furthermore，the degradation effect of PAM was better in acidic and neutral solutions. Based on the quenching experiments, SO4-• and •OH are the main active radicals in Co3O4-GO/PMS system. PMS is activated by mental ion and generated SO4-• to remove PAM. After 5 runs of reuse, PAM degradation efficiency still exceeded 95.7%.

Sewage sludge-derived TiO2/Fe/Fe3C-biochar composite as an efficient heterogeneous catalyst for degradation of methylene blue

Novel TiO2/Fe/Fe3C-biochar composite, as a heterogeneous catalyst, has been synthesized by a single-step route, where sewage sludge (SS) and different ratios of nanoparticles (NPs: Fe and Ti) impregnated with chitosan using coagulation and flocculation techniques for subsequent thermal decomposition at 800 °C. The physiochemical properties of samples have been characterized thoroughly and employed in methylene blue (MB) degradation tests. It was found that NPs ratio and chitosan support have significant influences on the properties and catalytic activity of catalysts. Chitosan inclusion successfully improves the surface area and mesoporosity of composites, while high contents of Fe integration reduce surface area and active site (Fe3C) due to Fe0 agglomeration. Though, Ti incorporation produces Ti3+ that activated photosensitivity. Catalyst with the high mesoporous surface, Ti3+, selective Fe3C, and small Fe0 shows superior MB removal competency through concurrent adsorption, photodegradation, and H2O2 activation. Primarily OH and some O2− radicles participating in the degradation reactions evident from scavenging experiments. The maximum MB removal capacity evaluated as 376.9 mg L−1 in neutral pH. Moreover, the catalyst exhibits excellent material stability, recyclability, easy separability, and low Fe-ion leaching (0.11 mg L−1) after catalysis. This study provided new insight into a low-cost and environmentally friendly route of catalyst synthesis using SS, NPs, and chitosan, which concurrently advantageous to SS disposal and wastewater treatment.

Facile synthesis of Fe3O4/MIL-101 nanocomposite as an efficient heterogeneous catalyst for degradation of pollutants in Fenton-like system

An active Fe3O4/MIL-101 hybrid material was prepared via a simple in situ solvothermal method and characterized as a heterogeneous Fenton-like catalyst for Rhodamine B (RhB) degradation.

β-Cyclodextrin supported MoO3–CeO2nanocomposite material as an efficient heterogeneous catalyst for degradation of phenol

The β-cyclodextrin supported MoO3–CeO2nanocomposite material is an efficient heterogeneous catalyst for the degradation of phenol to non-toxic pollutants at room temperature with continuous stirring and without light irradiation.

Diatomite coated with Fe2O3 as an efficient heterogeneous catalyst for degradation of organic pollutant

Heterogeneous catalysts have been attracted considerable attention for degradation of organic pollutions to overcome the disadvantages of the homogeneous Fenton process. Diatomite-Fe2O3 hybrid material, honeycomb structure with circular pores synthesized as a heterogeneous catalyst for photo-Fenton degradation of organic contaminants by a novel method. The existence of Fe2O3 nanoparticles in the diatomite-Fe2O3 catalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The catalytic activities of the diatomite-Fe2O3 catalyst were evaluated by the degradation of organic dye under visible light irradiation (>420 nm) in the presence of hydrogen peroxide. The results showed that the catalyst exhibited excellent catalytic property for 99.14% decoloration and 73.41% TOC removal of Rhodamine B, which could be attributed to the synergetic effects of the adsorptive power of diatomite and the hydroxyl radicals produced by heterogeneous photo-Fenton reactions. In addition, the decoloration efficiency was still higher than 90% after the catalyst being used for 5 cycles. Hence, the simplicity and cost-effectiveness of the hybrid material could be very promising for synthesizing for high-efficiency visible-light photocatalyst in the degradation of organic pollutants.

Graphene oxide–Fe2O3 hybrid material as highly efficient heterogeneous catalyst for degradation of organic contaminants

Graphene oxide–Fe2O3 (GO–Fe2O3) hybrid material was synthesized as a heterogeneous catalyst for photo-Fenton degradation of organic contaminants by an easy and scalable impregnation. X-ray diffraction analysis and high-resolution transmission electron microscope analysis confirm the existence of the Fe2O3 nanoparticles in the GO–Fe2O3 catalyst. Fourier transform infrared spectroscopy analysis proves that the combination of Fe2O3 and GO sheet is due to the metal–carbonyl coordination. The catalytic activities of the GO–Fe2O3 catalyst were evaluated by the degradation of Rhodamine B and 4-nitrophenol under visible light irradiation (>420nm) in the presence of hydrogen peroxide. The results show that the catalyst exhibited excellent catalytic property at a wide pH range of 2.09–10.09 and stable catalytic activity after seven recycles, which could be attributed to the synergetic effects of the adsorptive power of GO and the hydroxyl radicals produced by heterogeneous photo-Fenton reactions. The present results suggest that the GO–Fe2O3 hybrid material can act as an efficient heterogeneous catalyst for degradation of organic contaminants, which may provide insight into the design and development of high-efficiency visible-light photocatalyst for water treatment.