scholarly journals Boosted Visible-Light Photodegradation of Methylene Blue by V and Co Co-Doped TiO2

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1946 ◽  
Author(s):  
Tianping Lv ◽  
Jianhong Zhao ◽  
Mingpeng Chen ◽  
Kaiyuan Shen ◽  
Dongming Zhang ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Transition Metal Ions ◽  
First Principles Calculation ◽  
Tio2 Photocatalyst ◽  
Tio2 Sample ◽  
X Ray ◽  
Co Doped

In this work, TiO2 photocatalysts, co-doped with transition metal ions vanadium (V) and cobalt (Co) ((V,Co)–TiO2), were synthesized by the sol–gel method. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption and desorption measurement, UV-Vis absorption and photoluminescence spectrum (PL) spectra. The results show that V and Co co-doping has significant effects on sample average crystalline grain size, absorption spectrum, recombination efficiency of photo-induced electron-hole pairs (EHPs), and photocatalytic degradation efficiency of methylene blue (MB). (V,Co)–TiO2 photocatalyst exhibits an obvious red shift of the absorption edge to 475 nm. Photocatalytic degradation rate of (V,Co)–TiO2 sample for MB in 60 min is 92.12% under a Xe lamp with a cut-off filter (λ > 400 nm), which is significantly higher than 56.55% of P25 under the same conditions. The first principles calculation results show that V and Co ions doping introduces several impurity energy levels, which can modulate the location of the valence band and conduction band. An obvious lattice distortion is produced in the meantime, resulting in the decrease in photo-generated EHP recombination. Thus, (V,Co)–TiO2 photocatalyst performance is significantly improved.

scholarly journals Preparation and Characterization of Visible-Light-Activated Fe-N Co-Doped TiO2and Its Photocatalytic Inactivation Effect on Leukemia Tumors

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kangqiang Huang ◽  
Li Chen ◽  
Jianwen Xiong ◽  
Meixiang Liao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Light Therapy ◽  
Cell Counting ◽  
Visible Absorption ◽  
X Ray ◽  
Photocatalytic Inactivation ◽  
Inactivation Efficiency ◽  
Co Doped

The Fe-N co-doped TiO2nanocomposites were synthesized by a sol-gel method and characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). Then the photocatalytic inactivation of Fe-N-doped TiO2on leukemia tumors was investigated by using Cell Counting Kit-8 (CCK-8) assay. Additionally, the ultrastructural morphology and apoptotic percentage of treated cells were also studied. The experimental results showed that the growth of leukemic HL60 cells was significantly inhibited in groups treated with TiO2nanoparticles and the photocatalytic activity of Fe-N-TiO2was significantly higher than that of Fe-TiO2and N-TiO2, indicating that the photocatalytic efficiency could be effectively enhanced by the modification of Fe-N. Furthermore, when 2 wt% Fe-N-TiO2nanocomposites at a final concentration of 200 μg/mL were used, the inactivation efficiency of 78.5% was achieved after 30-minute light therapy.

Preparation of Novel Ag–Si–TiO2 Composite and Research on Its Photocatalytic Degradation of Formaldehyde

2021 ◽  
Vol 13 (3) ◽  
pp. 371-380
Author(s):  
Yongjun Wu ◽  
Nina Xie ◽  
Lu Yu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Formaldehyde Concentration ◽  
Order Kinetic ◽  
Solution Ph ◽  
Visible Absorption ◽  
X Ray ◽  
Co Doped

A novel Ag–Si–TiO2 composite was prepared via sol–gel method for removing residual formaldehyde in shiitake mushroom. The structure of Ag–Si–TiO2 composite was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses. Ultraviolet-visible absorption spectroscopy (UV-Vis) and N2 adsorption-desorption tests showed that Ag and Si co-doped decreased the band gap, the Brunauer-Emmett-Teller (BET) specific surface area of the samples increased and the recombination probability of electron-hole pairs (e--h+) reduced. Effect on removal rate of formaldehyde with different Ag-Si co-doped content, formaldehyde concentration and solution pH were investigated, and the results showed that 6.0 wt%Ag-3.0 wt%Si-TiO2 samples had an optimum catalytic performance, and the degradation efficiency reached 96.6% after 40 W 365 nm UV lamp irradiation for 360 min. The kinetics of formaldehyde degradation by Ag–Si–TiO2 composite photocatalyst could be described by Langmuir-Hinshelwood first-order kinetic model.

Preparation of C, N and P co-doped TiO2 and its photocatalytic activity under visible light

2019 ◽  
Vol 12 (04) ◽  
pp. 1950045 ◽  
Author(s):  
Lin Zhao ◽  
Yanzhao Xie ◽  
Qiuyu Lin ◽  
Rongze Zheng ◽  
Yong Diao
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Soluble Starch ◽  
Doping Amount ◽  
X Ray ◽  
Composite Catalysts ◽  
One Step ◽  
Co Doped

A series of composite catalysts of C, N and P co-doped TiO2 were prepared by sol-gel method, using a biomass (soluble starch) dopant. The samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), fourier transform infrared (FTIR) spectroscopy. The results show that TiO2 is co-doped with C, N and P by one step. The resulting composite exhibited higher specific surface area, wider visible-light absorption band with respect to the pure TiO2. The sample calcined at 400∘C for 2[Formula: see text]h with a doping amount of 6[Formula: see text]g soluble starch showed the best electrochemical performance. The C, N and P co-doped TiO2 was also used for the degradation of methylene blue (MB) and degradation ratio was up to 98% in 80[Formula: see text]min under visible light irradiation.

Preparation and Photocatalytic Properties of La, Ce and Nonmetal N Co-Doped TiO2

2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Sol Gel ◽  
Light Response ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.

Sol–gel synthesis, X-ray photoelectron spectroscopy and electrical conductivity of Co-doped (La, Sr)(Ga, Mg)O3−δ perovskites

2007 ◽  
Vol 27 (13-15) ◽  
pp. 4291-4296 ◽  
Author(s):  
Riccardo Polini ◽  
Alessia Falsetti ◽  
Enrico Traversa ◽  
Oliver Schäf ◽  
Philippe Knauth
Keyword(s):  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Co Doped

Molecularly Imprinted TiO2/WO3-Coated Magnetic Nanocomposite for Photocatalytic Degradation of 4-Nitrophenol Under Visible Light

2016 ◽  
Vol 69 (6) ◽  
pp. 638 ◽  
Author(s):  
Shoutai Wei ◽  
Hualong Liu ◽  
Chiyang He ◽  
Ying Liang
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Fe3o4 Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Energy Resource ◽  
Precipitation Method ◽  
Adsorption Ability ◽  
Molecularly Imprinted ◽  
X Ray

In this paper, a molecularly imprinted TiO2/WO3-coated magnetic Fe3O4@SiO2 nanocomposite was developed for photocatalytic degradation. Fe3O4 nanoparticles were first prepared by a traditional co-precipitation method, and then a SiO2 shell was grown on the surface of the Fe3O4 nanoparticles. Finally, a 4-nitrophenol imprinted TiO2/WO3 coating was obtained on the surface of the Fe3O4@SiO2 nanocomposite via a sol-gel method and subsequent calcination. The new composite was characterised by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high resolution TEM (HRTEM) and vibrating sample magnetometry (VSM). In addition, the adsorption ability and photocatalytic activity of the composite were investigated. Results showed that the imprinted composite had higher adsorption ability for the template than the non-imprinted composite. The imprinted catalyst could degrade 4-nitrophenol under visible light with a first-order reaction rate of 0.1039 h–1, which was ~2.5 times that of the non-imprinted catalyst. The new imprinted catalyst showed good catalytic selectivity, an ease of being recycled by an external magnetic field, good reusability, no need for additional chemicals, and allows the possibility of utilising solar light as energy resource. Therefore, the catalyst can be potentially applied for ‘green’, low-cost and effective degradation of 4-nitrophenol in real wastewater.

The origin of ferromagnetism of Co-doped TiO2 nanoparticles: Experiments and theory investigation

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650296 ◽  
Author(s):  
Suyin Zhang ◽  
Zhongpo Zhou ◽  
Rui Xiong ◽  
Jing Shi ◽  
Zhihong Lu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
First Principles ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
First Principles Calculation ◽  
Ferromagnetic Behavior ◽  
X Ray ◽  
3D Electron ◽  
Co Doped

A series of Ti[Formula: see text]Co[Formula: see text]O[Formula: see text] ([Formula: see text] = 0.01, 0.03, 0.05, 0.07) nanoparticles were synthesized by sol–gel method. The X-ray diffraction, transmission electron microscopy, Raman analysis and X-ray photoelectron spectroscopy ruled out the signatures of Ti[Formula: see text], Co-clusters or any other oxides of Co. The ferromagnetic behavior was clearly observed at room temperature in doped samples with saturation magnetization [Formula: see text] of the order of 0.008–0.035 emu/g depending on doping concentrations. The saturation magnetization is found to be increased with the Co contents increasing from 1% to 7%. From the plot of the M–T curve, we obtain the [Formula: see text] as [Formula: see text][Formula: see text]515 K for 5% Co-doped TiO2. Oxygen vacancies were detected from the photoluminescence (PL) measurement. Magnetic properties analyses and PL analyses showed that oxygen vacancies probably played a major role in ferromagnetism of the Ti[Formula: see text]Co[Formula: see text]O2 system with Co substituting for Ti. The first-principles calculation was performed to investigate the magnetic properties of Co-doped TiO2 nanoparticles. It can be found that the major magnetic moment is from the 3d electron of Co. The experiment results are consistent with the first-principles calculation. The ferromagnetism derived from the spin-split of O-2p and Co-3d electron states caused by p–d orbit hybridization.

FABRICATION AND PHOTOCATALYTIC PROPERTIES OF TiO2 NANOFILMS CO-DOPED WITH Fe3+ AND Bi3+ IONS

2016 ◽  
Vol 23 (02) ◽  
pp. 1550099
Author(s):  
QIONGZHI GAO ◽  
XIN LIU ◽  
WEI LIU ◽  
FANG LIU ◽  
YUEPING FANG ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Dip Coating ◽  
Photocatalytic Properties ◽  
Molar Ratio ◽  
Coating Process ◽  
X Ray ◽  
Co Doped ◽  
Scanning Electron

In this work, the titanium dioxide ([Formula: see text]) nanofilms co-doped with [Formula: see text] and [Formula: see text] ions were successfully fabricated by the sol–gel method with dip-coating process. Methylene blue was used as the target degradation chemical to study the photocatalytic properties affected by different doping contents of [Formula: see text] and [Formula: see text] ions. The samples were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and infrared (IR) spectroscopy. The results indicated that both pure [Formula: see text] nanofilms and single-doped samples possessed the photocatalytic activity in degradation of methylene blue. However, when the nanofilms co-doped with [Formula: see text] and [Formula: see text] ions were fabricated at the molar ratio of 3:1 ([Formula: see text]:[Formula: see text]), they exhibited the best photocatalytic activity after the heat treatment at [Formula: see text]C for 2[Formula: see text]h. The wettability property test indicated that the [Formula: see text] nanofilms co-doped with [Formula: see text] and [Formula: see text] ions in the molar ratio 3:1 owned an excellent hydrophilic property.

Antiviral and Antibacterial Effects of Silver-Doped TiO2 Prepared by the Peroxo Sol-Gel Method

2019 ◽  
Vol 19 (11) ◽  
pp. 7356-7362 ◽  
Author(s):  
Benjawan Moongraksathum ◽  
Min-Yuan Chien ◽  
Yu-Wen Chen
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Influenza A ◽  
Sol Gel ◽  
Weight Ratio ◽  
Antibacterial Activities ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

A series of multifunctional silver-doped titanium dioxide (Ag/TiO2) nanocomposites with various silver contents were synthesized by the peroxo sol–gel method using TiCl4 as a precursor and H2O2 as a peptizing agent. The sol was used to coat a glass substrate, thereby forming a thin film. The antiviral and antibacterial activities of the Ag/TiO2 films and their use in the photocatalytic degradation of an aqueous solution of methylene blue were investigated. The as-prepared materials were characterized using high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The antiviral and antibacterial activities of the samples were tested against Escherichia coli, the influenza A virus (H1N1), and enterovirus. It was observed that an optimum Ag:TiO2 weight ratio of 1:100 enabled the highest activity in the photocatalytic degradation of an aqueous solution of methylene blue under irradiation with either ultraviolet or visible light. Moreover, the same composition remarkably exhibited extremely high antibacterial and virucidal effectivenesses greater than 99.99% against E. coli and infectious viruses after illumination with ultraviolet A. The presence of silver on TiO2 significantly enhanced its photocatalytic activity. Thus, the excellent photocatalytic activities and reusability of the Ag/TiO2 nanocomposite render it applicable as a coating material for several purposes.

Cobalt and sulfur co-doped TiO2 nanostructures with enhanced photo-response properties for photocatalyst

2017 ◽  
Vol 10 (05) ◽  
pp. 1750061 ◽  
Author(s):  
Qiu Jin ◽  
Chaoyin Nie ◽  
Qianqian Shen ◽  
Yusheng Xu ◽  
Yanzhong Nie
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Response Threshold ◽  
X Ray Diffraction ◽  
X Ray ◽  
Valence States ◽  
Transmission Electron ◽  
Photo Response ◽  
Co Doped

Cobalt (Co) and sulfur (S) co-doped titanium dioxide (TiO2) catalysts were synthesized via sol–gel method. The structure of TiO2was characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The valence states of elements were studied by X-ray photoelectron spectroscopy (XPS), and the optical-absorption properties of the catalysts were tested using the ultraviolet–visible (UV–Vis) spectrophotometer. The results showed that the grain sizes of Co and S co-doped TiO2 decreased with the increase of Co and S doping concentration within a certain range, and then the catalysts had obvious red shift on the absorption of visible light. Sample (2%Co–5%S–TiO2) showed excellent light absorption characteristics and the photo-response threshold increased significantly to about 760[Formula: see text]nm. Also, the further degradation test under visible light shows the 2%Co–5%S-TiO2 sample exhibit apparently improved degradation efficiency for Rhodamine B compared to the undoped one.

Sign in / Sign up

Export Citation Format

Share Document