scholarly journals Nanorod bundle-like silver cyanamide nanocrystals for the high-efficiency photocatalytic degradation of tetracycline

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10235-10242
Author(s):  
Yulin Li ◽  
Chencong Cao ◽  
Qing Zhang ◽  
Ying Lu ◽  
Yanxi Zhao ◽  
...  

Ag2NCN nanoparticles with nanorod bundle-like assemblies and a narrower bandgap were synthesized and demonstrated a high photocatalytic activity towards TC degradation.

NANO ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. 1850127 ◽  
Author(s):  
Chentao Zou ◽  
Zhiyuan Yang ◽  
Mengjun Liang ◽  
Yunpeng He ◽  
Yun Yang ◽  
...  

Bi metal deposited on Bi2MoO6 composite photocatalysts have been successfully synthesized via a simple reduction method at room temperature with using NaBH4 as the reducing agent. The photocatalytic activity of the composite was evaluated by degradation of rhodamine B (RhB) and bisphenol A (BPA) solution under visible light. The rate constant of Bi/Bi2MoO6 composite to RhB is 10.8 times that of Bi2MoO6, and the degradation rate constant of BPA is 6.9 times of that of Bi2MoO6. Nitrogen absorption–desorption isotherm proved that the increase of specific surface area is one of the reasons for the improvement of photocatalytic degradation activity of Bi/Bi2MoO6 composites. The higher charge transfer efficiency of Bi/Bi2MoO6 is found through the characterization of the photocurrent and impedance, which are attributed to the surface plasmon resonance (SPR) effect produced by the introduction of the metal Bi monomer in the composite. Free radical capture experiments proved that cavitation is the main active species. Based on the above conclusions, a possible mechanism of photocatalytic degradation is proposed.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhen Peng ◽  
Hua Tang ◽  
Yao Tang ◽  
Ke Fu Yao ◽  
Hong Hong Shao

TiO2/SiO2/Fe3O4(TSF) core-shell nanoparticles with good photocatalytic activity that are capable of fast magnetic separation have been successfully prepared by chemical coprecipitation and two-step sol-gel process. The as-prepared TSF nanoparticles were calcined at high temperature in order to transform the amorphous titanium dioxide into a photoactive crystalline phase. The calcined nanoparticles are composed of a Fe3O4core with a strong response to external magnetic fields, a SiO2intermediary layer, and a TiO2outshell. Vibration sample magnetometer (VSM) analysis confirms the superparamagnetism of calcined nanoparticles, which can enhance the recoverable properties of the novel photocatalyst. When the TiO2/SiO2/Fe3O4core-shell nanoparticles are added to the crude oily wastewater, they exhibit high photocatalytic activity in the degradation of crude oily wastewater. The oil concentration could be reduced to lower than 30 ppm within 20 minutes for the case of initial oil concentration less than 350 ppm. It has been found that the TSF nanoparticles could be easily separated from the wastewater and withdrawn by using an external magnetic field. The recovered TSF nanoparticles possess high efficiency in the degradation of crude oily wastewater even after three times successive reuse. The present results indicate that TSF core-shell nanoparticles possess great application perspectives in the degradation of crude oily wastewater.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Song Li ◽  
Xiaofeng Hao ◽  
Xiangdong Dai ◽  
Tao Tao

Semiconductor photocatalysis can be used to decompose various organic compounds in open air under aqueous conditions with solar energy. A cellulose nanofiber/TiO2 aerogel (CNFT) for rapid photocatalytic degradation of methylene blue (MB) solution was successfully fabricated through a facile hydrothermal method. TiO2 nanoparticles adhered to the surface of cellulose nanofibers as scaffold through a hydrogen bond and were well-distributed. The particle size distribution data showed that the mean diameter of TiO2 nanoparticles was around 6.8 nm. In the system of the as-prepared CNFT, CNF played important roles in adsorption of pollutant and in stopping the electron hole derived from TiO2 from recombining. The composite aerogel exhibited efficient photocatalytic activity in the degradation of pollutant (MB) under ultraviolet light (UV) and sunlight irradiation. The composite aerogel could be regarded as a green and portable photocatalyst, because it was promising for wastewater treatment application as a result of its good high photocatalytic activity and stability under ultraviolet light and sunlight irradiation.


2017 ◽  
Vol 41 (24) ◽  
pp. 15433-15438 ◽  
Author(s):  
Yan Xu ◽  
Shumin Wu ◽  
Xianliang Li ◽  
Yehang Huang ◽  
Zhuopeng Wang ◽  
...  

A nanosheet-constructed ZnO/ZnFe2O4 composite with high photocatalytic activity is obtained via the one-step pyrolysis of a Zn–Fe mixed-metal–organic framework precursor.


2018 ◽  
Vol 54 (2A) ◽  
pp. 164
Author(s):  
Nguyen Tan Lam

This paper presents a study on preparation of sulfur doped titanium dioxide using potassium fluorotitanate and sodium sulfate as precursors. The obtained results indicated that the doped TiO2 exhibited very high photocatalytic activity for degradation of methylene blue even under visible light. The increasing in the added sulfur amounts led to significantly increase in the degradation of methylene blue. When the S/TiO2 mole ratios increased from 10 to 25%, the degradation of methylene blue under compact light increased from 30.87% to 67.06%, respectively.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Mi-Hwa Baek ◽  
Ji-Sook Hong ◽  
Ji-Won Yoon ◽  
Jeong-Kwon Suh

Fe-TiO2supported on spherical activated carbon (Fe-TiO2/SAC) with different Fe contents was prepared by heat treatment process after ion exchange method. The prepared Fe-TiO2/SAC was characterized by SEM, EDS, and BET. Batch experiments for photocatalytic degradation of humic acid by Fe-TiO2/SAC were carried out in the fluidized bed photoreactor. It was found that 0 wt% Fe-TiO2/SAC had high photocatalytic activity in the wavelength range of 100~280 nm. However, Fe-TiO2/SAC with Fe contents of 0.4, 0.6, and 0.8 wt% exhibited higher photocatalytic activity than 0 wt% Fe-TiO2/SAC in the wavelength range of 315~400 nm compared to that of 100~280 nm. The optimum Fe content was 0.6 wt% for maximum photocatalytic degradation of humic acid. Moreover, Fe-TiO2/SAC does not require an additional process step for separation of photocatalyst from treated water after photocatalysis.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1523-1528 ◽  
Author(s):  
ZHEN PENG ◽  
KE-FU YAO ◽  
ZHENHUA LIAO ◽  
WENPENG FU

It is well-known that TiO 2 nanoparticles are highly efficient photocatalysts in decomposing organic substance in wastewater, especially when they are used in suspension state. However, if TiO 2 nanoparticles cannot be withdrawn and reused, it is difficult to apply them in purification of wastewater due to the economic consideration. In present work, TiO 2/ SiO 2/ Fe 3 O 4 core-shell magnetic nanoparticles, constituted by Fe 3 O 4 core, SiO 2 intermediary layer and the TiO 2 out-shell, have been prepared and applied in photocatalytic degradation of a modulated methylene blue containing water. The results indicate that the as-prepared TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles possess high photocatalytic activity and the methylene blue in wastewater can be degraded quickly. Through comparing with the photocatalytic performance of the famous commercial P 25 TiO 2 nanoparticles in the same reaction condition, it has been found that as-prepared TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles exhibit similar photocatalytic activity to commercial P 25 TiO 2 nanoparticles in the photocatalytic degradation of methylene blue containing water. But the TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles used in suspension state can be simply recovered from the liquid by using a magnet or a magnetic field. So the cost of wastewater purification by photocatalytic degradation with TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles can be significantly reduced through reuse of the photocatalyst. It implies that TiO 2/ SiO 2/ Fe 3 O 4 nanoparticles possess the potential for industrial application.


2014 ◽  
Vol 908 ◽  
pp. 195-198
Author(s):  
Jing Wang ◽  
Li Da Sun ◽  
Zi Jing Li ◽  
Yan Hua Tang

This study combines the template method and sol-gel method, prepares TiO2 photocatalytic materials with the cotton, leaves and towel gourd as the template, and then makes degradation of phenol in ultraviolet light with the prepared TiO2 photocatalysts. The results show that all the photocatalyst prepared with three kinds of templates have high photocatalytic activity, among which, the catalytic performance of cotton is better, leaves secondly, and towel gourd’s relatively poor. With cotton as templates for the preparation of TiO2 under UV irradiation for 6h, the degradation rate was 80%, leaves as template for the preparation of TiO2 under UV irradiation for 6h, the degradation rate was 63%, and with towel gourd as template for the preparation of TiO2 under UV irradiation for 6h, the degradation rate was 52%.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2681 ◽  
Author(s):  
Vinh Huu Nguyen ◽  
Quynh Thi Phuong Bui ◽  
Dai-Viet N. Vo ◽  
Kwon Taek Lim ◽  
Long Giang Bach ◽  
...  

In this study, we investigated sulfate-modified BiVO4 with the high photocatalytic activity synthesized by a sol-gel method in the presence of thiourea, followed by the annealing process at different temperatures. Its structure was characterized by thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The BiVO4 synthesized in the presence of thiourea and calcined at 600 °C (T-BVO-600) exhibited the highest photocatalytic degradation efficiency of methylene blue (MB) in water; 98.53% MB removal was achieved within 240 min. The reaction mechanisms that affect MB photocatalytic degradation on the T-BVO-600 were investigated via an indirect chemical probe method, using chemical agents to capture the active species produced during the early stages of photocatalysis, including 1,4-benzoquinone (scavenger for O2−), ethylenediaminetetraacetic acid disodium salt (scavenger for h+), and tert-butanol (scavenger for HO•). The results show that holes (h+) and hydroxyl radicals (HO•) are the dominant species of MB decomposition. Photoluminescence (PL) measurement results of terephthalic acid solutions in the presence of BiVO4 samples and BiVO4 powders confirm the involvement of hydroxyl radicals and the separation efficiency of electron-hole pairs in MB photocatalytic degradation. Besides, the T-BVO-600 exhibits good recyclability for MB removal, achieving a removal rate of above 83% after five cycles. The T-BVO-600 has the features of high efficiency and good recyclability for MB photocatalytic degradation. These results provide new insight into the purpose of improving the photocatalytic activity of BiVO4 catalyst.


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