scholarly journals Carbon Quantum Dots (CQDs) Decorated Bi2O3-x Hybrid Photocatalysts with Promising NIR-Light-Driven Photodegradation Activity for AO7

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1031 ◽  
Author(s):  
Tao Xian ◽  
Xiaofeng Sun ◽  
Lijing Di ◽  
Yongjie Zhou ◽  
Jun Ma ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Oxygen Vacancies ◽  
Carbon Quantum Dots ◽  
Light Irradiation ◽  
Light Illumination ◽  
Surface Oxygen ◽  
Simulated Sunlight ◽  
Nir Light

In this work, Bi2O3-x with surface oxygen vacancies was prepared through the NaBH4 reduction of Bi2O3. After that, carbon quantum dots (CQDs) were deposited onto the surface of the Bi2O3-x to obtain a series of the CQDs/Bi2O3-x composites. The HRTEM and XPS characterizations of the CQDs/Bi2O3-x composites suggest that the thickness of surface oxygen vacancies could be adjusted by changing the concentration of NaBH4 solution, and the intimate contact between CQDs and the Bi2O3-x is achieved. Acid orange 7 (AO7) was adopted as the target reactant for investigating the photocatalytic degradation activities of the CQDs/Bi2O3-x composites under simulated sunlight and NIR light irradiation. It is found that the photocatalytic activities of the samples are closely related to the concentration of NaBH4 and content of CQDs. The Bi2O3-x samples exhibit enhanced simulated-sunlight-driven photocatalytic activity compared with Bi2O3. Specifically, the optimal degradation efficiency of AO7 is achieved over the 3R-Bi2O3-x (concentration of NaBH4: 3 mmol/L), which is 1.38 times higher than the degradation AO7 efficiency over Bi2O3. After the decoration of the 3R-Bi2O3-x surface with CQDs, the simulated-sunlight-driven photocatalytic activity of the CQDs/Bi2O3-x composite could be further enhanced. Among the samples, the 15C/3R-Bi2O3-x sample reveals the highest photocatalytic activity, leading to an AO7 degradation percentage of ~97% after 60 min irradiation. Different from Bi2O3 and the 3R-Bi2O3-x, the 15C/3R-Bi2O3-x sample also exhibits near-infrared (NIR)-light-driven photocatalytic degradation activity. In addition, the intrinsic photocatalytic activity of CQDs/Bi2O3-x composite was further confirmed by the degradation of phenol under simulated sunlight and NIR light irradiation. The photocurrent response and electrochemical impedance spectroscopy (EIS) measurements confirm the efficient migration and separation of photogenerated charges in the CQDs/Bi2O3-x samples. The •OH and h+ are proved to be the main reactive species in the simulated sunlight and NIR light photocatalytic processes over the CQDs/Bi2O3-x composites. According to the above experiments, the photocatalytic degradation mechanisms of the CQDs/Bi2O3-x composites under simulated sunlight and NIR light illumination were proposed.

Influence of Mn2+ Ion on the Surface of BiOCl Catalyst for Photocatalytic Degradation of Methylene Green under Visible Light Illumination

2013 ◽  
Vol 764 ◽  
pp. 194-205 ◽  
Author(s):  
Bhawna Sarwan
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Reflectance Spectra ◽  
Light Irradiation ◽  
Light Illumination ◽  
Scanning Electron Micrographs ◽  
Methylene Green ◽  
Mn Doped

In the present investigation, hydrolysis method has been used to synthesize mangnese doped BiOCl. The catalyst was characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM) and diffusive reflectance spectra (DRS) methods. Interesting results have been obtained from diffusive reflectance spectra which depicted that there is a shift in the optical absorption edge towards higher wavelength, which indicates a decrease in the band gap upon Mn doping. The photocatalytic activity of Mn doped catalyst was evaluated from the photodegradation of methylene green (MG) aqueous solution under visible light irradiation. Mn2+ doping effectively improved the photocatalytic activity of BiOCl under visible light irradiation. The possible degradation pathway has been proposed for the photocatalytic degradation by using certain radical scavengers. The photocatalytic reaction mechanism of Mn doped BiOCl catalyst has also been tentatively discussed.

Carbon quantum dot-sensitized hollow TiO2 spheres for high-performance visible light photocatalysis

2021 ◽  
Author(s):  
Xianfeng Zhang ◽  
Zongqun Li ◽  
Shaowen Xu ◽  
Yaowen Ruan
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
High Performance ◽  
Carbon Quantum Dots ◽  
Visible Light Photocatalysis ◽  
Carbon Quantum Dot ◽  
Visible Light Photocatalytic

TiO2/CQD composites were synthesized through carbon quantum dots covalently attached to the surface of hollow TiO2 spheres for visible light photocatalytic degradation of organics.

Photocatalytic degradation of crystal violet dye using sulphur-doped carbon quantum dots

2021 ◽  
Author(s):  
Umairah Abd Rani ◽  
Law Yong Ng ◽  
Ching Yin Ng ◽  
Ebrahim Mahmoudi ◽  
Nur Hanis Hayati Hairom
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Degradation ◽  
Crystal Violet ◽  
Carbon Quantum Dots ◽  
Crystal Violet Dye

Enhanced photocatalytic degradation of Rhodamine B, antibacterial and antioxidant activities of green synthesised ZnO/N doped carbon quantum dots nanocomposites

2021 ◽  
Author(s):  
Aschalew Tadesse ◽  
Mebrahtu Hagos Kahsay ◽  
Neway Belachew ◽  
H C Ananda Murthy ◽  
Basavaiah Keloth
Keyword(s):  
Quantum Dots ◽  
Zinc Oxide ◽  
Photocatalytic Degradation ◽  
Rhodamine B ◽  
Environmental Remediation ◽  
Antioxidant Activities ◽  
Carbon Quantum Dots ◽  
Step Process ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

In order to explore an alternative photocatalyst for environmental remediation, we report the two-step process to synthesise the zinc oxide/nitrogen doped carbon quantum dots nanocomposites (ZnO@NCQDs NCs). In the first...

Sign in / Sign up

Export Citation Format

Share Document