Sulfite activation by oxidized pyrite for dye degradation assisted with oxygen

2022 ◽  
Author(s):  
Guangjun He ◽  
Dengjie Zhong ◽  
Yunlan Xu

Because pyrite is easily oxidized, thus the catalytic performance of pyrite-peroxymonosulfate (PMS) or peroxydisulfate (PDS) activation system will be significantly affected due to the low activation of PMS or PDS...

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 589 ◽  
Author(s):  
Mingliang Ma ◽  
Yuying Yang ◽  
Yan Chen ◽  
Fei Wu ◽  
Wenting Li ◽  
...  

In this manuscript, hollow flower-like ferric oxide/manganese dioxide/trimanganese tetraoxide (Fe3O4/MnO2/Mn3O4) magnetically separable microspheres were prepared by combining a simple hydrothermal method and reduction method. As the MnO2 nanoflower working as precursor was partially reduced, Mn3O4 nanoparticles were in situ grown from the MnO2 nanosheet. The composite microspheres were characterized in detail by employing scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), vibration sample magnetometer (VSM) and UV–visible spectrophotometer (UV–vis). Under visible light conditions, the test for degrading rhodamine B (RhB) was used to verify the photocatalytic activity of the photocatalyst. The results showed that the efficiency of the Fe3O4/MnO2/Mn3O4 photocatalyst in visible light for 130 min is 94.5%. The catalytic activity of photocatalyst far exceeded that of the Fe3O4/MnO2 component, and after four cycles, the catalytic performance of the catalyst remained at 78.4%. The superior properties of the photocatalyst came from improved surface area, enhanced light absorption, and efficient charge separation of the MnO2/Mn3O4 heterostructure. This study constructed a green and efficient valence heterostructure composite that created a promising photocatalyst for degrading organic contaminants in aqueous environments.


2017 ◽  
Vol 48 (1) ◽  
pp. 146-161 ◽  
Author(s):  
Yongchun Dong ◽  
Fu Li ◽  
Xueting Zhao ◽  
Bowen Cheng ◽  
Weimin Kang ◽  
...  

Polyacrylonitrile nanofibrous membranes ( n-PAN-FMs) with different fibre diameters were prepared using electrospinning process and modified with hydroxylamine hydrochloride. The modified n-PAN-FMs were further coordinated with Fe3+ ions to produce a series of the modified n-PAN-FMs Fe complexes, and the catalytic activity of which was investigated as the heterogeneous Fenton catalyst for the dye degradation. The effect of fibre diameter on modification and coordination of n-PAN-FMs as well as the catalytic activity of the resulting complexes was also examined. The results indicated that increasing fibre diameter proportionally enhanced the amidoximation degree of n-PAN-FMs. The modified n-PAN-FMs consisting of small fibre diameters easily coordinated with Fe3+ ions, especially at high temperature to form the complex with high Fe content at the same conditions. Besides, these complexes exhibited the catalytic performance for the dye degradation in the dark and under visible irradiation at a wide pH range. The complex with middle fibre diameter showed a stronger catalytic performance than the complexes with much bigger or smaller fibre diameter due mainly to its large specific surface area and the proper size pores among fibres as well as better water affinity.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Zhizhong Ding ◽  
Yongchun Dong ◽  
Bing Li

Polytetrafluoroethylene (PTFE) fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III) and Cu(II) and a rare metal ion Ce(III) to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III) and Cu(II) content of the complexes. Fe(III) ions fixed on the fiber showed the better catalytic performance than Cu(II) and Ce(III) ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II) ions could significantly improve the catalytic activity of the complexes.


2019 ◽  
Vol 10 ◽  
pp. 718-724 ◽  
Author(s):  
Michael D Ballentine ◽  
Elizabeth G Embry ◽  
Marco A Garcia ◽  
Lawrence J Hill

The current study investigates whether metal deposition onto an existing nanorod can be carried out using an ionic liquid, and the effect this has on catalytic performance. Platinum, gold, and silver nanoparticles were deposited onto CdSe@CdS (core@shell) nanorods from metal salts in an ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) without additional surfactants or reducing agents. Photocatalytic dye degradation experiments showed that catalysts with platinum particles deposited using the ionic liquid out-performed similar materials synthesized using organic solvents and ligands. We concluded that metal particles can be deposited onto well-defined semiconductor nanorods using ionic liquids and metal salts without the need for additional reagents, and the deposited particles did not cause significant aggregation even when these materials were taken into organic media. It is possible that a broad range of metal/semiconductor heterostructured particles can be prepared using the methods reported here.


RSC Advances ◽  
2016 ◽  
Vol 6 (75) ◽  
pp. 70747-70755 ◽  
Author(s):  
Huijie Dong ◽  
Mingyu Wei ◽  
Jun Li ◽  
Jia Fang ◽  
Long Gao ◽  
...  

The supported graphitic carbon nitride on MCM-41 was prepared through an in situ thermal approach and was successfully used as an efficient catalyst for dyes degradation with peroxymonosulfate.


Sign in / Sign up

Export Citation Format

Share Document