Ultrathin HNb3O8 nanosheets with oxygen vacancies for enhanced photocatalytic oxidation of amines under visible light irradiation

2019 ◽  
Vol 7 (10) ◽  
pp. 5493-5503 ◽  
Author(s):  
Junli Chen ◽  
Hai Wang ◽  
Zhiqiang Zhang ◽  
Lifeng Han ◽  
Yonghui Zhang ◽  
...  

Ultrathin HNb3O8 nanosheets with oxygen vacancies were successfully synthesized by a simple hydrothermal process. HNb3O8 NSs showed excellent photocatalytic activity.

2014 ◽  
Vol 955-959 ◽  
pp. 2267-2275 ◽  
Author(s):  
Rong Liu ◽  
Shi Duo Zhao ◽  
Xue Lin

Ba0.6Mg0.4TiO3 (BMT) particles with different morphologies were synthesized through hydrothermal method and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are tetragonal structure. FESEM shows that BMT crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV-visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BMT photocatalysts are about 2.37 - 2.51 eV. The as-prepared BMT photocatalysts exhibite higher photocatalytic activities in the degradation of methyl orange (MO) under visible light irradiation (λ > 420 nm) compared with traditional N-doped TiO2 (N-TiO2) and pure BaTiO3 (BTO). The high photocatalytic performance of BMT photocatalysts could be attributed to the recombination restraint of the e-/h+ pairs resulting from doping of Mg2+ ions. The influence of morphologies upon the photocatalytic properties of BMT was studied. Furthermore, BMT nanowires reveal the highest photocatalytic activity. Up to 94.0% MO is decolorized after visible light irradiation for 360 min.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
S. Mary Margaret ◽  
Albin John P. Paul Winston ◽  
S. Muthupandi ◽  
P. Shobha ◽  
P. Sagayaraj

In this study, visible-light-driven ZnO microrod-rGO heterojunction composites were successfully synthesized via a facile and scalable hydrothermal process. The prepared photocatalyst heterojunction was examined using different techniques including XRD, SEM, FTIR, UV-Vis spectroscopy, and TGA to reveal their crystal phase, morphology, and other optical properties. The photocatalytic performance of the obtained ZnO-rGO composites was measured by the photodegradation of phenol under visible light illumination. The addition of graphene over the catalyst exhibited an enhanced photocatalytic activity for phenol degradation due to its high surface area and decreasing rate of electron-hole separation. Kinetic studies proved that the degradation of phenol process happened by following the pseudo-first-order kinetic model. The effective conditions for degradation of phenol using ZnO-rGO composite were 0.2 g L-1catalyst dose, pH -4, and initial concentration 20 ppm of phenol solution. Comparing with ZnO microrods, the heterojunction composite degraded the organic pollutants of phenol solution up to 84.2% of efficiency displaying the highest photocatalytic activity, whereas urchin-like ZnO catalyst exhibited much less photocatalytic activity for phenol degradation under visible light irradiation. This result envisages immense properties, showing a great potential industrial application for the removal of phenolic wastewater.


2018 ◽  
Vol 876 ◽  
pp. 52-56 ◽  
Author(s):  
Huu Vinh Nguyen ◽  
Tran Van Thuan ◽  
Sy Trung Do ◽  
Duy Trinh Nguyen ◽  
Dai Viet Nguyen Vo ◽  
...  

We report the facial synthesis of BiVO4crystals with different morphologies by the solvothermal and hydrothermal process. The phase structure and morphology as-synthesized samples were characterized by XRD, FE-SEM, and UV-vis DRS spectroscopy. We also investigated the photocatalytic activity of BiVO4for the decomposition of rhodamine B (RhB) under visible light irradiation. The results showed that oliver-like BiVO4was obtained when using the mixed solvent of ethylene glycol and water while starflower-like BiVO4was obtained using the mixed solvent of ethylene glycol monomethyl ether and water. The hydrothermal evolution process the BiVO4product with a rod-like morphology. Oliver-like BiVO4with pure monoclinic scheelite phase and high specific surface area exhibits efficient photodegradation of RhB (k = 7.82x10-3min-1).


2018 ◽  
Vol 42 (23) ◽  
pp. 19237-19244 ◽  
Author(s):  
Mona Hosseini-Sarvari ◽  
Zeinab Hosseinpour ◽  
Mehdi Koohgard

In this study, Ag/TiO2 nanotubes (Ag/TNT) were synthesized via simple hydrothermal process, and this photocatalyst was successfully exploited in thiocyanation reactions at room temperature under visible light irradiation.


2011 ◽  
Vol 179-180 ◽  
pp. 192-196
Author(s):  
Ye Cong ◽  
Peng Qin ◽  
Xuan Ke Li ◽  
Zhi Jun Dong ◽  
Guan Ming Yuan

Nitrogen and lanthanum co-doped nanocsystalline titania photocatalysts were prepared by a homogeneous precipitation-hydrothermal process. The photocatalytic activity of the prepared samples on photodegradation of rhodamine B in visible light irradiation was studied. The nitrogen and lanthanum co-doping could greatly improve the photocatalytic activity of titania in visible light irradiation, probablely due to a synergistic effect of co-doping. The nitrogen doping could narrow the band gap of titania and enhance the utilization efficiency of visible light, while the lanthanum doping could accelerate the separation of photo-generated electrons and holes. Furthermore, the lanthanum doping could increase the adsorption of organic pollutants on the surface of photocatalyst.


2013 ◽  
Vol 596 ◽  
pp. 43-49
Author(s):  
Shinnosuke Noguchi ◽  
Toru Tokutome ◽  
Shinji Iwamoto

Niobium modified titania samples were prepared by thermal reaction of titanium tetraisopropoxide and niobium pentaethoxide in 1,4-butanediol at 300 °C (solvothermal method), and the products were nitrified in an NH3 flow at 600 °C. The physicochemical property of the thus-obtained N-and Nb-co-doped titanias and visible-light response photocatalytic activity of FeOx-loaded N-and Nb-co-doped titanias were investigated. The N-and Nb-co-doped titanias had larger absorptions in the visible-light range as compared to the only N-doped titania samples. In ESR spectra of the Nb-modified TiO2 samples annealed at 300 °C after the nitrification, signals due to Ti3+ and oxygen vacancies, which accelerate the recombination of the photo-generated electrons and holes, were clearly observed. On the other hand, for the N-and Nb-co-doped titanias annealed at 500 °C, the signals due to Ti3+ and oxygen vacancies decreased significantly. Actually, the FeOx-loaded N-and Nb-co-doped samples annealed at 500 °C exhibited a higher photocatalytic activity for a photocatalytic decomposition of acetaldehyde under visible-light irradiation.


2020 ◽  
Vol 7 (9) ◽  
pp. 2809-2822
Author(s):  
Dan You ◽  
Dajun Shi ◽  
Qingrong Cheng ◽  
Yanling Chen ◽  
Zhiquan Pan

CdS@Mn-ZIF-67 heterojunction photocatalyst exhibited excellent photocatalytic activity for TC degradation and hydrogen evolution under visible light irradiation and are more effective than the single Mn-ZIF-67 or the hollow CdS nanospheres.


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