scholarly journals Enhanced Activation of Persulfate by Co-Doped Bismuth Ferrite Nanocomposites for Degradation of Levofloxacin Under Visible Light Irradiation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3952 ◽  
Author(s):  
Xin Zhong ◽  
Zheng-Shuo Zou ◽  
Hu-Lin Wang ◽  
Wei Huang ◽  
Bin-Xue Zhou

In this study, magnetic visible light driven photocatalysts (bismuth ferrite, Bi2Fe4O9, BFO and Co-doped bismuth ferrite, Co-BFO) were successfully prepared by the facile hydrothermal method. The catalyst was used in the application of heterogeneous persulfate (PS) system under visible LED light irradiation for the degradation of levofloxacin (LFX), proving to be an excellent photocatalyst when evaluated by various characterization methods. The effect of Co-doping in the BFO structure was investigated that the decrease of band gap width and the generated photoelectrons and holes would effectively reduce the recombination of photogenerated electron-hole pairs, leading to the enhancement photocatalytic activity. The results demonstrated that Co-BFO catalyst had a high photodegradation efficiency over a wide pH range of 3.0–9.0 and the Co-BFO-2 composite displayed the optimal catalytic performance. It was found that the degradation rate of LFX by Co-BFO-2 catalyst was 3.52 times higher than that of pure BFO catalyst under visible light condition. The free radical trapping experiments and EPR tests demonstrated that superoxide, photogenerated holes and sulfate radicals were the main active species in the photocatalytic degradation of LFX. And a possible photocatalytic degradation mechanism of LFX was proposed in the Vis/Co-BFO/PS process. These findings provided new insight of the mechanism of heterogeneous activation of persulfate by Co-BFO under visible light irradiation.

2019 ◽  
Vol 9 (17) ◽  
pp. 4614-4628 ◽  
Author(s):  
Gongduan Fan ◽  
Jiajun Zhan ◽  
Jing Luo ◽  
Jin Zhang ◽  
Zhong Chen ◽  
...  

A H2O2-modified titanate nanomaterial was synthesized to improve catalytic activity. The influencing factors, intermediate product transformation pathways and degradation mechanism of the photodegradation process of NPX by the HTNM were studied.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shuo Xu ◽  
Xiaoya Gao ◽  
Wenfeng Xu ◽  
Pengfei Jin ◽  
Yongmei Kuang

A series of ultrathin BiOCl 2D nanosheet photocatalysts were prepared by the TBAOH-assisted hydrolysis method in water. The effects of tetrabutylammonium hydroxide (TBAOH) dosages, chlorine source, preparation pH value, ultrasonic treatment, and magnetic stirring on the photocatalytic degradation dynamics of carbamazepine were examined under visible-light irradiation to optimize the preparation parameters. It was found that ultrathin BiOCl prepared with TBAOH dosages of 1 mmol and chlorine source of NaCl in the pH of 2 upon magnetic stirring of 6 h displayed the highest photocatalytic degradation rate constant (0.0038 min−1) of carbamazepine, which is 7.6 times higher than that with the ordinary BiOCl (without TBAOH). To clarify the mechanism on the outstanding photocatalytic activity of ultrathin BiOCl, the elemental composition/state, micromorphology, and separation efficiency of photogenerated electron-hole pairs were investigated by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and photoluminescence (PL). Results showed that the presence of oxygen vacancy, ultrathin nanosheet structure, and improved separation efficiency of photogenerated electron-hole pairs contributed to the excellent photocatalytic degradation activity of ultrathin BiOCl. The obtained result provides a novel method to fabricate ultrathin BiOCl with excellent photocatalytic degradation activity of carbamazepine under visible-light irradiation.


RSC Advances ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 5331-5337 ◽  
Author(s):  
Yuichi Yamaguchi ◽  
Sho Usuki ◽  
Kenji Yamatoya ◽  
Norihiro Suzuki ◽  
Ken-ichi Katsumata ◽  
...  

A visible-light-responsive Rh–Sb co-doped SrTiO3 photocatalyst (STO:Rh,Sb) via a solid-state reaction was successfully developed, following pulverization by using ball-milling.


Different weight percentages (0.25-1.00 wt%) of Nitrogen (Non-Metal) and Manganese (Metal) co-doped nano titania were synthesized by sol-gel method and characterized by XRD, UV-vis.DRS, FT-IR, XPS, SEM and TEM. The XRD results has shown that all the prepared catalysts are in anatase phase indicating that co-doping of N and Mn did not affect the crystal structure of TiO2 . From the UV-vis.DRS spectra a significant absorption shift towards visible region was noticed in N and Mn co-doped TiO2 and their presence was confirmed by XPS and FT-IR results. SEM and TEM results showed spherical nanoparticles with average particle size of 9 nm. Photocatalytic efficiency of synthesized nano materials was tested on non-biodegradable organophosphorous pesticide, Malathion under visible light irradiation. The effect of dopant concentration, pH, catalyst dosage, and initial pesticide concentration on photocatalytic degradation of malathion was studied and optimum conditions were established. Among the synthesized samples 0.50 wt% N & 1.00 wt% Mn-TiO2 exhibited best photocatalytic performance. Photoluminiscent spectroscopy (PL) was used to examine the rate of production of oxidative species, hydroxyl radicals which play key role in photocatalytic degradation.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4577
Author(s):  
Kun-Yauh Shih ◽  
Yen-Ling Kuan ◽  
En-Rui Wang

In this study, bismuth oxybromide/reduced graphene oxide (BiOBr/RGO), i.e. BiOBr-G nanocomposites, were synthesized using a one-step microwave-assisted method. The structure of the synthesized nanocomposites was characterized using Raman spectroscopy, X-ray diffractometry (XRD), photoluminescence (PL) emission spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet-visible diffuse reflection spectroscopy (DRS). In addition, the ability of the nanocomposite to degrade methylene blue (MB) under visible light irradiation was investigated. The synthesized nanocomposite achieved an MB degradation rate of above 96% within 75 min of continuous visible light irradiation. In addition, the synthesized BiOBr-G nanocomposite exhibited significantly enhanced photocatalytic activity for the degradation of MB. Furthermore, the results revealed that the separation of the photogenerated electron–hole pairs in the BiOBr-G nanocomposite enhanced the ability of the nanocomposite to absorb visible light, thus improving the photocatalytic properties of the nanocomposites. Lastly, the MB photo-degradation mechanism of BiOBr-G was investigated, and the results revealed that the BiOBr-G nanocomposites exhibited good photocatalytic activity.


2018 ◽  
Vol 221 ◽  
pp. 320-328 ◽  
Author(s):  
Chu-Ya Wang ◽  
Ying-Jie Zhang ◽  
Wei-Kang Wang ◽  
Dan-Ni Pei ◽  
Gui-Xiang Huang ◽  
...  

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