Improved Photocatalytic Activity of Copper Heterostructure Composites (Cu–Cu2O–CuO/AC) Prepared by Simple Carbothermal Reduction

2014 ◽  
Vol 67 (5) ◽  
pp. 749 ◽  
Author(s):  
Hongchao Ma ◽  
Yifeng Liu ◽  
Yinghuan Fu ◽  
Chunling Yu ◽  
Xiaoli Dong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Carbothermal Reduction ◽  
Treatment Time ◽  
Carbon Support ◽  
Treatment Temperature ◽  
X Ray

Cu–Cu2O–CuO/activated carbon heterostructure composites with visible-light activity have been successfully synthesized by a simple carbothermal reduction procedure using CuSO4 as a single precursor. The resultant samples were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy measurements. The results showed that the Cu–Cu2O–CuO composites with size less than 10 nm dispersed well on the surface of activated carbon. Activated carbon played both a reducing agent and support role in the formation of Cu–Cu2O–CuO/activated carbon heterostructure composites. X-ray photoelectron spectroscopy analysis suggests that the outside of the nanoparticles is CuO and the inside of the nanoparticles is Cu metal and Cu2O. Moreover, the composition of Cu–Cu2O–CuO/activated carbon composites can be tailored by varying the Cu loading, heat-treatment temperature, and heat-treatment time. The photocatalytic activities of the catalysts were investigated by degrading reactive brilliant blue KN-R under visible-light irradiation. The Cu–Cu2O–CuO/activated carbon heterostructure composites showed excellent photocatalytic activity compared with other catalysts (pure CuO, Cu2O, Cu2O/activated carbon, CuO/activated carbon, and Cu2O–CuO/activated carbon), which is ascribed to synergistic action between the activated carbon support and photoactive copper species, and the presence of interfacial structures such as a Cu2O/CuO heterostructure, Cu/Cu2O (or CuO) Schottky barrier, and Cu2O/Cu/CuO ohmic heterojunction.

Preparation of Visible-Light-Responsive TiO2-xNx Photocatalyst by a Very Simple Method

2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflection ◽  
Ammonia Solution ◽  
Reflection Spectra ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Light Excitation

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

scholarly journals Photocatalytic Performance of SiO2/CNOs/TiO2 to Accelerate the Degradation of Rhodamine B under Visible Light

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1671 ◽  
Author(s):  
Weike Zhang ◽  
Yanrong Zhang ◽  
Kai Yang ◽  
Yanqing Yang ◽  
Jia Jia ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electronic Microscope

A silicon dioxide/carbon nano onions/titanium dioxide (SiO2/CNOs/TiO2) composite was synthesized by a simple sol-gel method and characterized by the methods of X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Fourier transform infrared (FTIR), thermogravimetric analysis (TG), differential scanning calorimeter (DSC) and UV-Vis diffuse reflectance spectra (UV-Vis DRS). In this work, the photocatalytic activity of the SiO2/CNOs/TiO2 photocatalyst was assessed by testing the degradation rate of Rhodamine B (RhB) under visible light. The results indicated that the samples exhibited the best photocatalytic activity when the composite consisted of 3% CNOs and the optimum dosage of SiO2/CNOs/TiO2(3%) was 1.5 g/L as evidenced by the highest RhB degradation rate (96%). The SiO2/CNOs/TiO2 composite greatly improved the quantum efficiency of TiO2. This work provides a new option for the modification of subsequent nanocomposite oxide nanoparticles.

scholarly journals Preparation and Characterization of Defective TiO2. The Effect of the Reaction Environment on Titanium Vacancies Formation

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2763
Author(s):  
Zuzanna Bielan ◽  
Szymon Dudziak ◽  
Agnieszka Sulowska ◽  
Daniel Pelczarski ◽  
Jacek Ryl ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Reaction ◽  
High Photocatalytic Activity ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Light Activity ◽  
Cheap Alternative

Among various methods of improving visible light activity of titanium(IV) oxide, the formation of defects and vacancies (both oxygen and titanium) in the crystal structure of TiO2 is an easy and relatively cheap alternative to improve the photocatalytic activity. In the presented work, visible light active defective TiO2 was obtained by the hydrothermal reaction in the presence of three different oxidizing agents: HIO3, H2O2, and HNO3. Further study on the effect of used oxidant and calcination temperature on the physicochemical and photocatalytic properties of defective TiO2 was performed. Obtained nanostructures were characterized by X-ray diffractometry (XRD), specific surface area (BET) measurements, UV-Vis diffuse reflectance spectroscopy (DR-UV/Vis), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. Degradation of phenol as a model pollutant was measured in the range of UV-Vis and Vis irradiation, demonstrating a significant increase of photocatalytic activity of defective TiO2 samples above 420 nm, comparing to non-defected TiO2. Correlation of EPR, UV-Vis, PL, and photodegradation results revealed that the optimum concentration of HIO3 to achieve high photocatalytic activity was in the range of 20–50 mol%. Above that dosage, titanium vacancies amount is too high, and the obtained materials’ photoactivity was significantly decreased. Studies on the photocatalytic mechanism using defective TiO2 have also shown that •O2− radical is mainly responsible for pollutant degradation.

Photocatalysis Reactivity in the Visible Light of B-Doped TiO2 Nanotube Arrays

2013 ◽  
Vol 860-863 ◽  
pp. 907-910
Author(s):  
Xiao Xia Lin ◽  
Jia Liu ◽  
De Gang Fu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectrum ◽  
Nanotube Arrays ◽  
X Ray Diffraction ◽  
Degradation Model ◽  
X Ray ◽  
Light Region

B-doped TiO2nanotube arrays (B-TNTs) were synthesized by anodization method combined with dip-calcination technique. The physicochemical properties and surface morphology were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectrum (DRS). Methyl blue (MB) solution was utilized as the degradation model to evaluate the photocatalytic activity of B-TNTs under visible light irradiation. The results show B-TNTs shifts the absorption edge of TiO2nanotube arrays to the visible light region and B-TNTs displays higher photocatalytic activity compared with undoped TNTs.

scholarly journals Enhanced Visible Light Photocatalytic Activity of Mesoporous AnataseTiO2Codoped with Nitrogen and Chlorine

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Xiuwen Cheng ◽  
Xiujuan Yu ◽  
Zipeng Xing ◽  
Lisha Yang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Visible Region ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Anatase mesoporous titanium dioxide codoped with nitrogen and chlorine (N-Cl-TiO2) photocatalysts were synthesized through simple one-step sol-gel reactions in the presence of ammonium chloride. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflection spectrum (UV-vis DRS). XRD results indicated that codoping with nitrogen and chlorine could effectively retard the phase transformation of TiO2from anatase to rutile and the growth of the crystallite sizes. XPS revealed that nitrogen and chlorine elements were incorporated into the lattice of TiO2through substituting the lattice oxygen atoms. DRS exhibited that the light absorption of N-Cl-TiO2in visible region was greatly improved. As a result, the band gap of TiO2was reduced to 2.12 eV. The photocatalytic activity of the as-synthesized TiO2was evaluated for the degradation of RhB and phenol under visible light irradiation. It was found that N-Cl-TiO2catalyst exhibited higher visible light photocatalytic activity than that of P25 TiO2and N-TiO2, which was attributed to the small crystallite size, intense light absorption in visible region, and narrow band gap.

scholarly journals SORPTION AND PHOTOCATALYTIC ACTIVITY ZNCUO (X=0,05 AND 0,15) TO AS (III) IN AN ALKALINE MEDIUM

2020 ◽  
pp. 792-804
Author(s):  
Ольга Ивановна Гырдасова ◽  
Лилия Александровна Пасечник ◽  
Владимир Николаевич Красильников ◽  
Владимир Трофимович Суриков ◽  
Михаил Владимирович Кузнецов
Keyword(s):  
Solid Solution ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Spectroscopy Data ◽  
Visible Radiation ◽  
X Ray ◽  
Visible Light Range ◽  
Doping Impurity

С использованием формиатогликолятных комплексов ZnCu(HCOO)(OCHCHO) (0 ≤ х ≤ 0,15) получены твердые растворы ZnCuO с 1D и композиты ZnCuO / CuO со сферической морфологией агрегатов соответственно. Материалы апробированы в реакции фотоокисления As(III) при воздействии ультрафиолетового и видимого излучения. Установлено, что медь является эффективной допирующей примесью в составе твердого раствора ZnCuO (0 ≤ х ≤ 0,1). Присутствие ее в оболочке композита ZnCuO / CuO негативно влияет на фотоактивность материала вплоть до подавления фотокатализа в видимом световом диапазоне. Показана также сорбционная эффективность материалов к мышьяку независимо от состава и морфологии материала. Согласно данным рентгеновской фотоэлектронной спектроскопии на поверхности образцов после сорбции мышьяк находится преимущественно в виде As(III) . 1D solid solutions ZnCuO and composites ZnCuO / CuO with spherical morphology of aggregates from formate glycolate complexes ZnCuO (HCOO)(OCHCHO) (0 ≤ x ≤ 0,15) were obtained. All materials have been tested in the reaction of As(III) photooxidation upon exposure to ultraviolet and visible radiation. It was found that copper is an effective doping impurity in the composition of the solid solution ZnCuO (0 ≤ x ≤ 0,1). Its presence in the shell of the ZnCuO / CuO composite negatively affects the photoactivity of the material up to suppression of photocatalysis in the visible light range. The sorption efficiency of materials for arsenic is also shown, regardless of the composition and morphology of the material. According to x-ray photoelectron spectroscopy data, the surface of the samples after sorption contains arsenic mainly in the form of As(III).

scholarly journals Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

scholarly journals Synthesis of C-N-S-Tridoped TiO2 from Vietnam Ilmenite Ore and Its Visible Light-Driven-Photocatalytic Activity for Tetracyline Degradation

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Nguyen Thi Lan ◽  
Vo Hoang Anh ◽  
Hoang Duc An ◽  
Nguyen Phi Hung ◽  
Dao Ngoc Nhiem ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
Photocatalytic Decomposition ◽  
Raman Scattering Spectroscopy ◽  
X Ray ◽  
Visible Light Driven

In this study, C-N-S-tridoped TiO2 composite was fabricated from TiO2 prepared from ilmenite ore and thiourea by means of hydrothermal method. The obtained material was characterized by X-ray diffraction, Raman scattering spectroscopy, UV-Vis diffuse reflectance spectroscopy, nitrogen adsorption-desorption isotherms, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that C-N-S-tridoped TiO2 material has a large specific surface area, showing good photocatalytic activity on the degradation of antibiotic tetracycline in visible light region. The study on the mechanism of tetracycline photodegradation using the liquid chromatography with mass spectrometry was performed. It was found that tetracycline has been degraded over C-N-S-tridoped TiO2 catalyst into many different intermediates which can eventually be converted into CO2 and H2O. The kinetics of photocatalytic decomposition of tetracycline were investigated. In addition, the obtained material could catalyze well the degradation of other antibiotics (ciprofloxacin and chloramphenicol) and dyes (rhodamine-B, methylene blue, and organe red). The catalyst was stable after five recycles with slight loss of catalytic activity, which indicates great potential for practical application of C-N-S-tridoped TiO2 catalyst in treatment of wastewater containing tetracycline in particular or antibiotics in general.

Fabrication of Novel Z-Scheme Bi2WO6/NaBiO3 Nanocomposites with Enhanced Photocatalytic Activity in the Degradation of 2,3-Dichlorophenol

2020 ◽  
Vol 20 (5) ◽  
pp. 3105-3116 ◽  
Author(s):  
Xin-Yue Gu ◽  
Qiu Wang ◽  
Da-Peng Zhang ◽  
Xin-Xiang Geng ◽  
Zhen-Xing Zha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
Energy Levels ◽  
Degradation Process ◽  
Photoelectrochemical Performance ◽  
X Ray ◽  
Oxidative Species

The Z-scheme Bi2WO6/NaBiO3 nanocomposites were first fabricated by a facile hydrothermal method, and were then characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometer, Fourier-transform-infrared spectroscopy, X-ray photoelectron spectroscopy and N2 adsorption–desorption. The as-prepared Bi2WO6/NaBiO3 nanocomposites exhibit outstanding photocatalytic activity and recyclability. A 98.4% photodegradation of 2,3-dichlorophenol (50 mg·L−1) was attained in the presence of Bi2WO6/NaBiO3 (1:10) under the visible-light irradiation in 30 min. In particular, the photocatalytic mechanism has been discussed in detail, based on four aspects: (1) oxidative species, (2) photoelectrochemical performance, (3) conduction band and valence band energy levels and (4) possible transition states and reactions. In conclusion, O−2 is the main active oxidative species in the Bi2WO6/NaBiO3 nanocomposite. The material has higher photocurrent and visible light adsorption but lower electron–hole pairs recombination, which contributes to distinguished photocatalytic efficiency. The Z-scheme photocatalytic path was proposed and the possible degradation process and routes have been summarized.

Fabrication and Characterization of Photocatalyst Coatings by Heat Treatment in Carbon Powder for TiC Coatings

2017 ◽  
Vol 263 ◽  
pp. 137-141
Author(s):  
Su Jun Guan ◽  
Liang Hao ◽  
Hiroyuki Yoshida ◽  
Hiroshi Asanuma ◽  
Fu Sheng Pan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Oxygen Vacancies ◽  
Treatment Temperature ◽  
Carbon Powder ◽  
Treatment Conditions ◽  
Fabrication And Characterization ◽  
Mechanical Coating

Photocatalyst coatings on alumina (Al2O3) balls had been successfully fabricated by mechanical coating technique, with titanium carbide (TiC) powder and subsequent heat treatment in carbon powder. The effect of heat treatment conditions in carbon powder on the formed compounds, surface morphology and photocatalytic activity of photocatalyst coatings was investigated. XRD results show that the formed compounds change with increasing the heat treatment temperature in carbon powder, and rutile TiO2 on the surface of TiC coatings at 1073 K and 1173 K. The generated oxygen vacancies confirmed by XPS measurement, are in favor of narrowing band gap to enhance the visible-light photocatalytic activity of photocatalyst coatings. The photocatalytic activity of photocatalyst coatings has been effectively enhanced, and the samples fabricated at 1073 K and 1173 K for 2 h show higher activity. The fabrication strategy provides us a facile preparation procedure of visible-light responsive photocatalyst coatings.

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