scholarly journals Facile Synthesis of “Boron-Doped” Carbon Dots and Their Application in Visible-Light-Driven Photocatalytic Degradation of Organic Dyes

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1560 ◽  
Author(s):  
Zhili Peng ◽  
Yiqun Zhou ◽  
Chunyu Ji ◽  
Joel Pardo ◽  
Keenan J. Mintz ◽  
...  

Carbon dots (C-dots) were facilely fabricated via a hydrothermal method and fully characterized. Our study shows that the as-synthesized C-dots are nontoxic, negatively charged spherical particles (average diameter 4.7 nm) with excellent water dispersion ability. Furthermore, the C-dots have a rich presence of surface functionalities such as hydroxyls and carboxyls as well as amines. The significance of the C-dots as highly efficient photocatalysts for rhodamine B (RhB) and methylene blue (MB) degradation was explored. The C-dots demonstrate excellent photocatalytic activity, achieving 100% of RhB and MB degradation within 170 min. The degradation rate constants for RhB and MB were 1.8 × 10−2 and 2.4 × 10−2 min−1, respectively. The photocatalytic degradation performances of the C-dots are comparable to those metal-based photocatalysts and generally better than previously reported C-dots photocatalysts. Collectively considering the excellent photocatalytic activity toward organic dye degradation, as well as the fact that they are facilely synthesized with no need of further doping, compositing, and tedious purification and separation, the C-dots fabricated in this work are demonstrated to be a promising alternative for pollutant degradation and environment protection.

2013 ◽  
Vol 67 (4) ◽  
pp. 722-728 ◽  
Author(s):  
Jian Wang ◽  
Jingqun Gao ◽  
Jun Wang ◽  
Yu Zhai ◽  
Zhongxing Wang ◽  
...  

Ag/TiO2 coated composite was prepared via sol-gel method in order to elucidate its application in magnetic field assisted photocatalytic degradation of dyes. Through the degradation of organic dyes, the key influences such as Ag amount, heat-treated temperature and time on the photocatalytic activity of Ag/TiO2, as well as UV irradiation time, rotational speed, dye concentration and magnetic sheet number on the photocatalytic degradation were studied. Results showed that the Ag/TiO2 with 25 wt% Ag content heat-treated at 550 °C for 60 min has the best photocatalytic activity. With the increase of UV light irradiation time, rotational speed and magnetic sheet number, the degradation rate is improved. Different dye degradation proved that the method could universally be used.


2022 ◽  
Vol 2022 ◽  
pp. 1-18
Author(s):  
Avvaru Praveen Kumar ◽  
Dinesh Bilehal ◽  
Tegene Desalegn ◽  
Shalendra Kumar ◽  
Faheem Ahmed ◽  
...  

Degradation of dye pollutants by the photocatalytic process has been regarded as the most efficient green method for removal organic dyes from contaminated water. The current research work describes the synthesis of Fe3O4@SiO2@Ru hybrid magnetic composites (HMCs) and their photocatalytic degradation of two azo dye pollutants, methyl orange (MO) and methyl red (MR), under irradiation of visible light. The synthesis of Fe3O4@SiO2@Ru HMCs involves three stages, including synthesis of Fe3O4 magnetic microspheres (MMSs), followed by silica (SiO2) coating to get Fe3O4@SiO2 MMSs, and then incorporation of presynthesized Ru nanoparticles (~3 nm) onto the surface of Fe3O4@SiO2 HMCs. The synthesized HMCs were characterized by XRD, FTIR, TEM, EDS, XPS, BET analysis, UV-DRS, PL spectroscopy, and VSM to study the physical and chemical properties. Furthermore, the narrow band gap energy of the HMC photocatalyst is a significant parameter that provides high photocatalytic properties due to the high light adsorption. The photocatalytic activity of synthesized Fe3O4@SiO2@Ru HMCs was assessed by researching their ability to degrade the aqueous solution of MO and MR dyes under visible radiation, and the influence of various functional parameters on photocatalytic degradation has also been studied. The results indicate that the photocatalytic degradation of MO and MR dyes is more than 90%, and acid media favors better degradation. The probable mechanism of photodegradation of azo dyes by Fe3O4@SiO2@Ru HMC catalysts has been proposed. Furthermore, due to the strong ferromagnetic Fe3O4 core, HMCs were easily separated from the solution after the photocatalytic degradation process for reuse. Also, the photocatalytic activity after six cycles of use is greater than 90%, suggesting the stability of the synthesized Fe3O4@SiO2@Ru HMCs.


RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 39295-39303
Author(s):  
Jiangang Qu ◽  
Jiaqi Qian ◽  
Mengtao Wu ◽  
Qinghui Mao ◽  
Min Li

BiVO4/Ag/cotton-K composite material exhibited excellent photocatalytic activity and recyclability, and the photodegradation mechanism of RB5 by BiVO4/Ag/cotton-K was also proposed.


2015 ◽  
Vol 3 (44) ◽  
pp. 22136-22144 ◽  
Author(s):  
Renzhong Zhang ◽  
Xueqin Wang ◽  
Jun Song ◽  
Yang Si ◽  
Xingmin Zhuang ◽  
...  

Flexible hierarchical mesoporous TiO2 NP modified TiO2 nanofibrous membranes with excellent photocatalytic activity towards organic dyes were fabricated by the combination of an electrospinning technique and in situ polymerization.


2017 ◽  
Vol 41 (8) ◽  
pp. 3134-3142 ◽  
Author(s):  
Zheng Qiao ◽  
Tingjiang Yan ◽  
Wenjuan Li ◽  
Baibiao Huang

In2S3/In(OH)3 heterostructures which were synthesized via an in situ anion exchange reaction and the hydrothermal process displayed excellent photocatalytic activity compared to pure components and the reported In2S3/In2O3.


2019 ◽  
Vol 26 (05) ◽  
pp. 1850196 ◽  
Author(s):  
CHUANSHENG CHEN ◽  
QUN FANG ◽  
SHIYI CAO ◽  
YONGXIANG YAN

In order to consider the performance enhancement and feasibility of practical application, this research work discussed the effects of different ions on the photocatalytic activity of TiO2/Fe2O3 hybrids in detail, involving H[Formula: see text], OH−, NH[Formula: see text], and NO[Formula: see text]. The TiO2/Fe2O3 hybrids were prepared by organic electrolyte-assisted sol–gel method under UV irradiation, and their function mechanisms were analyzed. Experiment results show that the resultant TiO2/Fe2O3 hybrids possess excellent photocatalytic activity and photocatalytic stability for degradation of organics under acid condition (pH 2–8). Notably, the NO[Formula: see text] ions could accelerate degradation of rhodamine B and methyl orange, and the recyclability of TiO2/Fe2O3 hybrids can be greatly enhanced in the co-existence of NO[Formula: see text] and NH[Formula: see text]. Meanwhile, this symbiosis of NO[Formula: see text] and NH[Formula: see text] is proven able to buffer the solution pH in photocatalysis. Furthermore, the prominent photocatalytic activity of TiO2/Fe2O3 hybrids for organic pollutants was mainly attributed to the formation of hydroxyl radicals (OH). The synthetic products show great potential applications in purification of air or wastewater that contains ammonia-nitrogen molecules.


2021 ◽  
Vol 9 (08) ◽  
pp. 29-35
Author(s):  
Guilherme S Padovani ◽  
Samuel A. P. T. Carvalho ◽  
F. R. De Paula

This study attempted to produce polymeric microfibers with low-cost and photocatalytic properties, making it possible to remedy two modern problems, plastic disposal and irregular effluent disposal, for which we used the solution blows pinning (SBS) technique to produce recycled polystyrene (PS) microfibers (recycled waste from transparent barrel pen), the use of the SBS also has good mobility for the benefit of fibers, allowing the fibers to be produced directly under the surface where intend to be used, through the SEM was found the ideal concentration to produce uniform microfibers. With the minor average diameter, FTIR analysis of the fibers showed peak characteristics of PS, demonstrating that most of the transparent barrel pen is composed of PS. The as-prepared fibers of recycled PS were incorporated into their polymer solution with a TiO2 Degussa P25 concentration of 10% (w/w) concerning the polymer mass. For the study of photocatalytic activity, the dye Rhodamine B was used as an indicator. Excellent photocatalytic activity, XRD pattern of PS and PS/TiO2-10% fibers showed PS and TiO2 in two phases, anatase and rutile.


2019 ◽  
Vol 814 ◽  
pp. 487-492
Author(s):  
Xi Hao Lin ◽  
Pei Song Tang ◽  
Bei Bei Wang ◽  
Hai Qiang Tang

Using zinc acetate, glycerol alcohol and sodium hydroxide as principal raw materials, the ZnO microspheres were prepared by hydrothermal method at 200°C. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and diffuse reflectance spectroscopy (DRS). Using methyl orange as the degradation object, the photocatalytic activities and recycling stability of ZnO were characterized. The results show that ZnO samples are spherical and the average diameter is approximately 3-4μm. Moreover, the bandgap width is 3.1eV. Under ultraviolet light irradiation, it is testified that ZnO shows a excellent photocatalytic activity for the degradation of methyl orange. From experience, we can draw a conclusion that the ZnO samples were in line with first-order kinetics, with an apparent rate constant of 0.016min-1. At the same time, ZnO showed excellent recycling performance. Although the samples have been recycled three times, it still maintained high photocatalytic activity.


2021 ◽  
Author(s):  
Velayutham Shanmuganathan ◽  
Jayaraj Santhosh Kumar ◽  
Raman Pachaiappan ◽  
Paramasivam Thangadurai

The objective of this work was to study the effect of transition metal ion doping (1 wt% of Mn, Fe, Co, Ni, and Cu) in indium oxide (In2O3) on its photocatalytic activity to degrade organic dyes, which are considered potential environment pollutants.


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