Hydrothermal Preparation of Visible-Light-Driven N-Br-CodopedTiO2Photocatalysts

Using a facile hydrothermal method, N-Br-codopedTiO2photocatalyst that had intense absorption in visible region was prepared at low temperature (100°C), through a direct reaction between nanocrystalline anataseTiO2solution and cetyltrimethylammonium bromide (CTAB). The results of X-ray photoelectron spectroscopy (XPS) showed the existence of N-Ti-N, O-Ti-N-R,Ti3+(attribute to the doped Br atoms by charge compensation), andTiOxNyspecies, indicating the successful codoping of N and Br atoms, which were substituted for lattice oxygen without any influence on the crystalline phase ofTiO2. In contrast to the N-doped sample, the N-Br-codopedTiO2photocatalyst could more readily photodegrade methylene blue (MB) under visible-light irradiation. The visible-light catalytic activity of thus-prepared photocatalyst resulted from the synergetic effect of the doped nitrogen and bromine, which not only gave high absorbance in the visible-light range, but also reduced electron-hole recombination rate.

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Hydrothermal fabrication and characterization of novel CeO2/PbWO4 nanocomposite for enhanced visible-light photocatalytic performance

Applied Water Science ◽

10.1007/s13201-021-01429-x ◽

2021 ◽

Vol 11 (6) ◽

Author(s):

S. Selvi ◽

Ranjith Rajendran ◽

N. Jayamani

Keyword(s):

Visible Light ◽

Photocatalytic Performance ◽

Visible Region ◽

Hydrothermal Preparation ◽

Electron Hole ◽

Photoexcited Electron ◽

Visible Light Driven ◽

Fabrication And Characterization ◽

Visible Light Photocatalytic

AbstractIn this revision, a series of novel visible-light-driven (VLD) CeO2/PbWO4 nanocomposites (NCs) were effectively fabricated by facile hydrothermal preparation way. The UV–Vis absorption spectra exposed that CeO2 NPs prolonged the adsorption edge of the CeO2/PbWO4 composite to the extensive visible region, which allied to decreases of the bandgap. As-prepared CeO2/PbWO4 NCs revealed superior photocatalytic action under visible-light and could degrade the Methylene Blue (MB) dye solution in 140 min. The photodegradation efficacy of CeO2/PbWO4 NCs was improved catalytic activity, which is around 1.45 and 2.7 times that of CeO2 and PbWO4 nanoparticles (NPs) individually. Besides, the CeO2/PbWO4 catalysts display notable stability and reusability performance in four succeeding cycles. The development in the photocatalytic enactment of combined CeO2/PbWO4 nanocomposite could be recognized not only to the sturdy visible-light absorption responses and separating the photoexcited electron–hole pairs. Also, the plausibly systematic illumination of charge transference and exploitation of reactive species for superior photocatalytic action in visible-light have been discussed. It is projected that the CeO2/PbWO4 NCs could be used as effective photocatalysts for promising applications for environmental wastewater refinement.

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Preparation and Photocatalytic Performance for Degradation of Rhodamine B of AgPt/Bi4Ti3O12 Composites

Nanomaterials ◽

10.3390/nano10112206 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2206

Author(s):

Gaoqian Yuan ◽

Gen Zhang ◽

Kezhuo Li ◽

Faliang Li ◽

Yunbo Cao ◽

...

Keyword(s):

Visible Light ◽

Noble Metal ◽

Rhodamine B ◽

Photocatalytic Performance ◽

Bimetallic Nanoparticles ◽

Resonance Effect ◽

Visible Region ◽

Photogenerated Electron ◽

Pt Nanoparticles ◽

Electron Hole

Loading a noble metal on Bi4Ti3O12 could enable the formation of the Schottky barrier at the interface between the former and the latter, which causes electrons to be trapped and inhibits the recombination of photoelectrons and photoholes. In this paper, AgPt/Bi4Ti3O12 composite photocatalysts were prepared using the photoreduction method, and the effects of the type and content of noble metal on the photocatalytic performance of the catalysts were investigated. The photocatalytic degradation of rhodamine B (RhB) showed that the loading of AgPt bimetallic nanoparticles significantly improved the catalytic performance of Bi4Ti3O12. When 0.10 wt% noble metal was loaded, the degradation rate for RhB of Ag0.7Pt0.3/Bi4Ti3O12 was 0.027 min−1, which was respectively about 2, 1.7 and 3.7 times as that of Ag/Bi4Ti3O12, Pt/Bi3Ti4O12 and Bi4Ti3O12. The reasons may be attributed as follows: (i) the utilization of visible light was enhanced due to the surface plasmon resonance effect of Ag and Pt in the visible region; (ii) Ag nanoparticles mainly acted as electron acceptors to restrain the recombination of photogenerated electron-hole pairs under visible light irradiation; and (iii) Pt nanoparticles acted as electron cocatalysts to further suppress the recombination of photogenerated electron-hole pairs. The photocatalytic performance of Ag0.7Pt0.3/Bi4Ti3O12 was superior to that of Ag/Bi4Ti3O12 and Pt/Bi3Ti4O12 owing to the synergistic effect between Ag and Pt nanoparticles.

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Enhanced visible-active photocatalytic behaviors observed in Mn-doped BiFeO3

Modern Physics Letters B ◽

10.1142/s0217984918501853 ◽

2018 ◽

Vol 32 (17) ◽

pp. 1850185 ◽

Cited By ~ 5

Author(s):

Yun-Hui Si ◽

Yu Xia ◽

Ya-Yun Li ◽

Shao-Ke Shang ◽

Xin-Bo Xiong ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Band Gap ◽

Diffuse Reflectance Spectroscopy ◽

X Ray Diffraction ◽

Electron Hole ◽

X Ray ◽

Mn Doped ◽

Hole Recombination ◽

Narrow Band Gap Semiconductors

A series of BiFeO3 and BiFe[Formula: see text]Mn[Formula: see text]O3 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by a hydrothermal method. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy (EDS) and UV–Vis diffuse reflectance spectroscopy, and their photocatalytic activity was studied by photocatalytic degradation of methylene blue in aqueous solution under visible light irradiation. The band gap of BiFeO3 was significantly decreased from 2.26 eV to 1.90 eV with the doping of Mn. Furthermore, the 6% Mn-doped BiFeO3 photocatalyst exhibited the best activity with a degradation rate of 94% after irradiation for 100 min. The enhanced photocatalytic activity with Mn doping could be attributed to the enhanced optical absorption, increment of surface reactive sites and reduction of electron–hole recombination. Our results may be conducive to design more efficient photocatalysts responsive to visible light among narrow band gap semiconductors.

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Synergetic effect of dual co-catalysts on the activity of BiVO4 for photocatalytic carbamazepine degradation

RSC Advances ◽

10.1039/c9ra07152k ◽

2019 ◽

Vol 9 (71) ◽

pp. 41977-41983 ◽

Cited By ~ 2

Author(s):

Beibei Wang ◽

Ping Li ◽

Chunlei Du ◽

Yan Wang ◽

Daxin Gao ◽

...

Keyword(s):

Visible Light ◽

Synergetic Effect ◽

Co Catalysts ◽

Visible Light Driven ◽

Three Components

An efficient visible-light driven three components photocatalyst for carbamazepine (CBZ) degradation has been assembled by co-loading reduction cocatalyst Pt and oxidation cocatalyst Co3O4 (MnOx) on BiVO4. An obvious synergetic effect is observed.

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Synthesis and Photocatalytic Degradation Performance of g-C3N4/ CoAPO-5/rGO Ternary Composite

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.281.848 ◽

2018 ◽

Vol 281 ◽

pp. 848-853

Author(s):

Ling Fang Qiu ◽

Xiao Bin Qiu ◽

Zhi Wei Zhou ◽

Shu Wang Duo

Keyword(s):

Visible Light ◽

Carbon Nitride ◽

Photocatalytic Performance ◽

Doping Content ◽

Electron Mediator ◽

Electron Hole ◽

Obvious Effect ◽

Ternary Composite ◽

Hole Recombination ◽

Binary Composite

Graphitic carbon nitride is a promising photocatalyst for environmental purification, but the photocatalytic performance is limited significantly due to its narrow visible-light adsorption and high photo-reduced electron-hole recombination rate. This work developed a novel way to overcome the two defects and obtained obvious effect. CoAPO-5 was used to broaden visible-light adsorption range by conducting g-C3N4/CoAPO-5 binary composite. In further, rGO was integrated into the binary system to form novel ternary composite. rGO performs as a electron mediator, which can inhibit photo-reduced electron-hole recombination efficiently. The samples were characterized by XRD, SEM, PL, IR and DRS. The photocatalytic performances for degrading RhB (10mg/L) indicated that g-C3N4/CoAPO-5/rGO have much higher activity than g-C3N4/CoAPO-5 because of synergistic effect. When the doping content of rGO in g-C3N4/CoAPO-5 was 0.5%, the degradation efficiency was improved by 14%.

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Fabrication of a Cu2O-Au-TiO2 Heterostructure with Improved Photocatalytic Performance for the Abatement of Hazardous Toluene and α-Pinene Vapors

Catalysts ◽

10.3390/catal10121434 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1434

Author(s):

Joon Yeob Lee ◽

Jeong-Hak Choi

Keyword(s):

Photoelectron Spectroscopy ◽

Photocatalytic Oxidation ◽

Separation Efficiency ◽

Diffuse Reflectance Spectrum ◽

Visible Region ◽

Pure Tio2 ◽

Great Promise ◽

Light Sources ◽

Electron Hole ◽

X Ray

In the current research, a Cu2O-Au-TiO2 heterostructure was fabricated via a step-wise photodeposition route to determine its possible application in the photocatalytic oxidation of hazardous vapors. The results of electron microscopy and X-ray photoelectron spectroscopy confirm the successful fabrication of the Cu2O-Au-TiO2 heterostructure. Strong absorption in the visible region, along with a slight red-shift in the absorption edge, was observed in the UV–vis diffuse reflectance spectrum of Cu2O-Au-TiO2 composite, which implies that the composite can generate a greater number of photoexcited charges necessary for photocatalytic reaction. Toluene and α-pinene, as common gas contaminants in the indoor atmosphere, were employed to assess the photooxidation efficiency of the Cu2O-Au-TiO2 composite. Importantly, photocatalytic activity results indicate that the Cu2O-Au-TiO2 composite showed excellent photodegradation performance compared to pure TiO2 and Cu2O-TiO2 and Au-TiO2, where photocatalytic efficiency was approximately 92.9% and 99.9% for toluene and α-pinene, respectively, under standard daylight illumination. The increased light-harvesting capacity and boosted separation efficiency of electron-hole pairs were mainly accountable for improved degradation performance of the Cu2O-Au-TiO2 composite. In addition, the degradation efficiencies for toluene and α-pinene by the Cu2O-Au-TiO2 composite were also examined under three different light sources: 0.32 W white, blue and violet LEDs. The findings of this work suggested a great promise of effective photooxidation of gas pollutants by the Cu2O-Au-TiO2 composite.

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Synergetic effect of metal-doped GO and TiO2 on enhancing visible-light-driven photocatalytic hydrogen production from water splitting

Energy Sources Part A Recovery Utilization and Environmental Effects ◽

10.1080/15567036.2019.1629130 ◽

2019 ◽

Vol 43 (4) ◽

pp. 484-494 ◽

Cited By ~ 2

Author(s):

Mohamed S. Atrees ◽

Ebraheim E. Ebraheim ◽

Mohamed E. M. Ali ◽

Yasser M. Khawassek ◽

Mohamed S. Mahmoud ◽

...

Keyword(s):

Hydrogen Production ◽

Visible Light ◽

Water Splitting ◽

Synergetic Effect ◽

Photocatalytic Hydrogen Production ◽

Visible Light Driven ◽

Metal Doped

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The Photocatalytic and Antibacterial Performance of Nitrogen-Doped TiO2: Surface-Structure Dependence and Silver-Deposition Effect

Nanomaterials ◽

10.3390/nano10112261 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2261 ◽

Cited By ~ 2

Author(s):

Abdul Wafi ◽

Erzsébet Szabó-Bárdos ◽

Ottó Horváth ◽

Mihály Pósfai ◽

Éva Makó ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Surface Area ◽

Photocatalytic Performance ◽

Visible Region ◽

Bet Surface Area ◽

Doped Tio2 ◽

X Ray ◽

Nitrogen Doped ◽

Visible Light Driven

Catalysts for visible-light-driven oxidative cleaning processes and antibacterial applications (also in the dark) were developed. In order to extend the photoactivity of titanium dioxide into the visible region, nitrogen-doped TiO2 catalysts with hollow and non-hollow structures were synthesized by co-precipitation (NT-A) and sol–gel (NT-U) methods, respectively. To increase their photocatalytic and antibacterial efficiencies, various amounts of silver were successfully loaded on the surfaces of these catalysts by using a facile photo-deposition technique. Their physical and chemical properties were evaluated by using scanning electron microscopy (SEM), transmission electron microscopy–energy dispersive X-ray spectroscopy (TEM–EDS), Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), and diffuse reflectance spectra (DRS). The photocatalytic performances of the synthesized catalysts were examined in coumarin and 1,4-hydroquinone solutions. The results showed that the hollow structure of NT-A played an important role in obtaining high specific surface area and appreciable photoactivity. In addition, Ag-loading on the surface of non-hollow structured NT-U could double the photocatalytic performance with an optimum Ag concentration of 10−6 mol g−1, while a slight but monotonous decrease was caused in this respect for the hollow surface of NTA upon increasing Ag concentration. Comparing the catalysts with different structures regarding the photocatalytic performance, silverized non-hollow NT-U proved competitive with the hollow NT-A catalyst without Ag-loading for efficient visible-light-driven photocatalytic oxidative degradations. The former one, due to the silver nanoparticles on the catalyst surface, displayed an appreciable antibacterial activity, which was comparable to that of a reference material practically applied for disinfection in polymer coatings.

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Efficient Degradation of Atrazine by Magnetic CoFe2O4/g-C3N4 Catalyzed Peroxymonosulfate and Its Enhancement of Photocatalytic Ability Under Visible-Light

Science of Advanced Materials ◽

10.1166/sam.2019.3572 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1764-1772 ◽

Cited By ~ 5

Author(s):

Ji-Bin An ◽

Dai-Peng Hu ◽

Yan-Lin Li ◽

Na-Li Chen

Keyword(s):

Visible Light ◽

Environmental Remediation ◽

Catalytic Performance ◽

Catalyst Loading ◽

X Ray Diffraction ◽

Electron Hole ◽

Photocatalytic Ability ◽

Water Matrix ◽

Visible Light Driven ◽

Calcination Method

The Magnetic photocatalytic cobalt ferrite/graphitic-carbon nitride (CoFe2O4/g-C3N4) composites with enhanced photocatalytic activity were successfully fabricated through a simple calcination method. Scanning electron microscopy, powder X-ray diffraction, and infrared spectroscopy were applied to characterize the samples. The photocatalytic behavior of CoFe2O4/g-C3N4 was assessed by degradation of atrazine in photo Fenton-like system under visible light irradiation. The results showed that CoFe2O4/g-C3N4 with 2.0 gL–1 catalyst loading in the presence of 1 mM peroxymonosulfate (PMS) exhibited the best catalytic performance, and more than 97% of atrazine was destructed in 12 min. This enhancement could be attributed to the synergistic effect between CoFe2O4 and g-C3N4 promoting longer lifetime of separated electron–hole pairs derived from the formation of the heterojunction between CoFe2O4 and g-C3N4. This could enhance the composite-mediated activation of PMS for the visible-light driven degradation of atrazine. Moreover, the quenching tests showed that sulfate radicals were responsible for the atrazine degradation. CoFe2O4/g-C3N4 composites have strong magnetic ability, thus their recovery from water could be readily achieved by applying external magnetic field. This study demonstrates reasonable performance of the PMS/CoFe2O4/g-C3N4 system in water matrix as potentially important candidate for environmental remediation.

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