Synthesis of sol–gel derived holmium aluminium garnet on exfoliated g-C3N4: a novel visible-light-driven Z-scheme photocatalyst for the degradation of sunset yellow FCF

2019 ◽  
Vol 30 (22) ◽  
pp. 20132-20143 ◽  
Author(s):  
Lina Pavasaryte ◽  
Sridharan Balu ◽  
Thomas C. K. Yang
RSC Advances ◽  
2017 ◽  
Vol 7 (41) ◽  
pp. 25314-25324 ◽  
Author(s):  
Lin Xiao ◽  
Li Youji ◽  
Chen Feitai ◽  
Xu Peng ◽  
Li Ming

A highly efficient and elaborately structured visible-light-driven catalyst composed of mesoporous TiO2 (MT) doped with Ag+-coated graphene (MT-Ag/GR) has been successfully fabricated by a sol–gel and solvothermal method.


2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Ooi Yee Khai ◽  
Leny Yuliati ◽  
Siew Ling Lee

New visible light driven photocatalysts of 1 mol% Cr doped TiO2 supported on TUD-1 have been successfully synthesized. The Cr-TiO2/xTUD-1 (x = 10, 20, 30, 40 and 50) photocatalysts were prepared via surfactant-free sol-gel method followed by wet impregnation procedures. XRD analysis revealed that both TiO2 and Cr were incorporated in the highly porous siliceous matrix. FTIR analysis showed the existence of Si-O-Ti in all the materials. As observed, tetrahedral-coordinated Ti species were dominant in Cr-TiO2/10TUD-1, Cr-TiO2/20TUD-1 and Cr-TiO2/30TUD-1. Meanwhile, octahedral- coordinated Ti species were the dominant species in Cr-TiO2/40TUD-1 and Cr-TiO2/50TUD-1. It has been demonstrated that the amount of TUD-1 as photocatalyst support affected the wavelength response and the bandgap energy of the resulting materials. All the materials have bandgap energy of ~2.9 eV. The photocatalytic performance of the synthesized materials was tested out in dye photodegradation under visible light irradiation at 298 K for 5 hours. Results showed that all Cr-TiO2/TUD-1 materials had higher photocatalytic activity than that of Cr-TiO2. This could be explained by the high surface area and porosity provided by TUD-1 in enhancing the adsorption and diffusivities of the dye molecules, hence leading to the promising photocatalytic activity. Among the materials prepared, Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation.


2020 ◽  
Vol 815 ◽  
pp. 152451 ◽  
Author(s):  
Mahdi Ranjeh ◽  
Farshad Beshkar ◽  
Omid Amiri ◽  
Masoud Salavati-Niasari ◽  
Hossein Moayedi

2012 ◽  
Vol 622-623 ◽  
pp. 883-888
Author(s):  
Natkritta Boonprakob ◽  
Natda Wetchakun ◽  
Sukon Phanichphant ◽  
Jun Chen ◽  
Burapat Inceesungvorn

Nitrogen-loaded TiO2(N-loaded TiO2), a visible-light driven catalyst, was successfully synthesized by the modified sol-gel method. Physical characterizations of the as-prepared catalysts have been performed by using X-ray diffraction (XRD), Diffuse reflectance UVvisspectroscopy(DRUVvis), Raman spectroscopyand BETspecific surface areain order to obtain structure-activity relationship. Results from Raman spectroscopy clearly suggested that N atoms were incorporated into the TiO2crystal lattice as evidenced by the vibrational peak of TiN in TiO2-xNx.DR UVvis results also suggested that the nitrogen dopant might be responsible for narrowing the TiO2band gap energy, thus resulting in a shift towards the visiblelight region. Photocatalytic activity of N-loaded TiO2evaluated through the degradation of methyl orange (MO)under visible light irradiation (l> 400 nm) indicated that all N-loaded photocatalysts exhibited significantly higher activities than the unloaded TiO2and Degussa P25 TiO2. According to the results from DR UV-vis, XRD and BET studies, the enhanced photoactivity observed from N-loaded samples might be due to a decrease in TiO2band gap energy and/or changes in chemical and physical properties of the materials upon loading with nitrogen.


2010 ◽  
Vol 62 (9) ◽  
pp. 2128-2133 ◽  
Author(s):  
T. Putta ◽  
M. C. Lu ◽  
J. Anotai

This research aimed to expand the activity of TiO2 down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO3, and 1°C/min, respectively. The undoped TiO2 synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO2 became even better when doped with tungsten. At the optimum W to TiO2 ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO2 could exhibit the photocatalytic activity under the visible light region.


2020 ◽  
Vol 12 (11) ◽  
pp. 1255-1264
Author(s):  
Nada D. Al-Khthami ◽  
Mohammed Alsawat ◽  
Reda M. Mohamed ◽  
Yousef G. Alghamdi ◽  
Zaki I. Zaki

In order to create a new design for an efficient photocatalyst, you need to decrease the obtained band gap and isolate the charge carriers photogenerated while setting up a new visible light methodology. The latter option could be accomplished via combination of catalyst in the metal oxide form over the surface of semiconductor. Hence, the current work aimed at synthesizing a new nanocomposite material from LaFeO3/g-C3N4 through the use of mesoporous silica as a template processing g-C3N4 higher surface area, which was subsequently decorated with LaFeO3. The LaFeO3 of variable content of 1∼4% was used to decorate our targeted basic material. The structure was confirmed by ordinary techniques, in addition to photocatalytic ability via splitting water reaction. g-C3N4 and LaFeO3 photocatalytic efficiencies were compared to the newly developed LaFeO3/g-C3N4 nanocomposites showing their outstanding activity. The optimum LaFeO3 content was confirmed as 3%, which gave higher photocatalytic efficiency against both g-C3N4 and LaFeO3 (34 and 21 times respectively). To enhance the catalytic system efficiency, a scavenger with a positive hole was added as glycerol. A maximum of five runs of higher efficient reuse was examined as required, as well as stable nanocomposite photocatalyst. The mesoporous structure, high surface area, and capacity of charge separation over the photocatalysis process were all investigated as main conditions which affect photocatalytic activity of LaFeO3/g-C3N4 nanocomposites.


2014 ◽  
Vol 38 (7) ◽  
pp. 3127-3136 ◽  
Author(s):  
Swati Sood ◽  
Surinder Kumar Mehta ◽  
Ahmad Umar ◽  
Sushil Kumar Kansal

Ultrasonic assisted sol–gel synthesized Bi-doped TiO2 mesoporous nanoparticles with a good crystallinity and high surface area were prepared. The 1% Bi-doped TiO2 catalyst showed the highest photocatalytic activity under visible light.


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