Novel p–n junction UiO-66/BiOI photocatalysts with efficient visible-light-induced photocatalytic activity

2018 ◽  
Vol 77 (5) ◽  
pp. 1441-1448 ◽  
Author(s):  
Yuejin Li ◽  
Xili Shang ◽  
Changhai Li ◽  
Xiaoming Huang ◽  
Jingjing Zheng
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Salicylic Acid ◽  
Visible Light ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Junction Structure ◽  
First Time

Abstract Novel visible-light-induced UiO-66/BiOI photocatalysts with a p–n junction structure have been prepared for the first time through a facile hydrothermal method. The prepared photocatalysts were characterized using the powder X-ray diffraction, high resolution transmission electron microscopy, scanning electron microscopy, UV–visible diffuse reflectance spectra, and N2 adsorption–desorption (Brunauer–Emmett–Teller) techniques respectively. The photodegradation performances of UiO-66/BiOI photocatalysts were evaluated by photodegrading salicylic acid under visible-light irradiation. The UiO-66/BiOI composites displayed much higher photocatalytic efficiencies than pure BiOI under visible light. When the content of UiO-66 was 5.2 wt%, the composite (UiO-66/BiOI-2) has the best photocatalytic activity. Most of the salicylic acid molecules can be degraded in 100 min. The degradation rate of UiO-66/BiOI-2 samples is higher than single BiOI and UiO-66. The enhanced photocatalytic performance of UiO-66/BiOI may be ascribed to the formation of p–n heterojunctions between BiOI and UiO-66, which facilitates the transfer and separation of the photogenerated charge carriers. After recycling of the photocatalyst for five times for the photodegradation of salicylic acid, more than 85% of salicylic acid could still be degraded in the fifth cycle, implying that the as-prepared photocatalysts are highly stable.

scholarly journals The Contrastive Research in the Photocatalytic Activity of BiOBr Synthesized by Different Reactants

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Wang Ling-Li ◽  
Ma Wan-Hong ◽  
Wang Shu-Lian ◽  
Zhang Yu ◽  
Jia Man-Ke ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Active Species ◽  
X Ray Diffraction ◽  
Toc Removal ◽  
Transmission Electron ◽  
Uv Visible ◽  
Adsorption Desorption

BiOBr nanoplates, marked asα-BiOBr andβ-BiOBr, were synthesized via hydrothermal method using cetylpyridinium bromide (CPB) and NaBr as reactants, respectively. X-Ray Diffraction (XRD), transmission electron microscope (TEM), N2adsorption/desorption, UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and cyclic voltammetry (CV) were employed to characterize the obtained BiOBr. The results showed thatα-BiOBr andβ-BiOBr can absorb visible light and both the band gaps of them were about 2.76 eV. Under visible light irradiation, the photodegradation of organic dye sulforhodamine (SRB) and salicylic acid (SA) usingα-BiOBr andβ-BiOBr as the catalysts was carried out. The reaction kinetic constants of the degradation of SRB byα-BiOBr andβ-BiOBr were 0.00602 min−1and 0.0047 min−1, respectively, which indicated that the photocatalytic activity ofα-BiOBr was higher than that ofβ-BiOBr. The UV-Vis DRS and total organic carbon (TOC) were also monitored, and the TOC removal rate ofα-BiOBr andβ-BiOBr was 86% and 48%, respectively. At the same time, hydrogen peroxide (H2O2) and active radicals were measured and analyzed, which showed that the main active species wasOH∙during the photocatalytic reaction.

SYNTHESIS OF Bi2WO6 MICROSPHERES WITH VISIBLE-LIGHT-DRIVEN PHOTOCATALYTIC PROPERTIES

2013 ◽  
Vol 12 (05) ◽  
pp. 1350035 ◽  
Author(s):  
GENGPING WAN ◽  
GUIZHEN WANG
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Large Scale ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Light Region ◽  
Visible Light Driven ◽  
Uv Visible

Bi 2 WO 6 microspheres constructed from nanosheets have been synthesized by a controllable solvothermal route in a large scale. The structure characterizations of the microspheres were investigated in detail by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). On the basis of XRD analysis and SEM observation of the products at different reaction time periods, a growth mechanism of Bi 2 WO 6 microspheres was proposed. UV-Visible diffuse reflectance (DR) spectrum of the prepared Bi 2 WO 6 microspheres demonstrates that they have absorption in the visible light region. The photocatalytic activity of Bi 2 WO 6 microspheres toward Rhodamine-B ( RhB ) degradation was investigated and the as-prepared products exhibited good photocatalytic activity in degradation of RhB under 300 W Xe lamp light irradiation.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Electron Hole ◽  
Electrochemical Impedance Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Hole Pair

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

Synthesis and photocatalytic activities of Nd-doped TiO2 mesoporous microspheres

2016 ◽  
Vol 09 (01) ◽  
pp. 1650013 ◽  
Author(s):  
Xijian Liu ◽  
Yangang Sun ◽  
Yeying Wang ◽  
Lijuan Zhang ◽  
Jie Lu
Keyword(s):  
Electron Microscopy ◽  
Light Irradiation ◽  
Xenon Lamp ◽  
X Ray Diffraction ◽  
Absorbance Spectroscopy ◽  
Transmission Electron ◽  
Mesoporous Microspheres ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Adsorption Desorption

Nd-doped TiO2 mesoporous microspheres with possessing regular micro/nanostructure were synthesized by a simple and facile method. The structure and optical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms and UV-Visible absorbance spectroscopy. It was revealed that Nd-doped TiO2 mesoporous microspheres are composed of primary nanoparticles with a particle size of [Formula: see text]25[Formula: see text]nm. The photocatalytic activities of all the samples were evaluated by degradation methyl orange (MO) in aqueous solution as a model reaction under xenon lamp light irradiation. The results showed that the doped samples demonstrated a higher photocatalytic activity than TiO2 mesoporous microspheres, and the MO of 10[Formula: see text]mg/mL almost could be completely degraded by the Nd-doped TiO2 mesoporous sample (the dosage of Nd salt to TiO2 is 6%) under xenon lamp light irradiation within 1[Formula: see text]h.

Hydrothermal Synthesis and Photocatalytic Properties of TiO2/SnS2 Nanocomposite

2014 ◽  
Vol 898 ◽  
pp. 23-26
Author(s):  
Jing Li ◽  
Wei Sun ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Photocatalytic Property ◽  
Deionized Water ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Chloride Pentahydrate

TiO2/SnS2 nanocomposite was synthesized via hydrothermal treatment of tin (IV) chloride pentahydrate, thioacetamide and TiO2 nanotubes in deionized water at 150 °C for 3 h. The structure, composition and optical property of the as-synthesized nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic property was tested in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation. It was observed that TiO2 nanotubes exhibited no photocatalytic activity, whereas TiO2/SnS2 nanocomposite exhibited photocatalytic activity in the reduction of aqueous Cr6+ under visible-light (λ > 420 nm) irradiation.

SYNTHESIS OF CROSS Bi2 WO6 MICROWAFERS WITH ENHANCED PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION

2012 ◽  
Vol 19 (01) ◽  
pp. 1250005 ◽  
Author(s):  
GUIZHEN WANG ◽  
GENGPING WAN ◽  
SHIWEI LIN
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
Orthorhombic Phase ◽  
Transmission Electron ◽  
Light Region ◽  
Uv Visible ◽  
Visible Diffuse Reflectance Spectrum ◽  
Better Than

Novel cross Bi2 WO6 microwafers have been fabricated by a facile acetone-assisted solvothermal method in high quantity. The structure characterizations of the microwafers were investigated in detail by means of X-ray powder diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The results indicate that the orthorhombic phase of Bi2 WO6 with high crystallinity can be obtained and each microwafer is polycrystalline in nature and organized by the nanoflake subunits. UV-visible diffuse reflectance spectrum of the prepared Bi2 WO6 microwafers demonstrates that they have absorption in the visible light region. The photocatalytic activity of cross Bi2 WO6 microwafers toward (Rhodamine B) RhB degradation under visible light was investigated, and it was found to be significantly better than that of Bi2 WO6 sample prepared by solid-state reaction (SSR-Bi2 WO6) .

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

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 Composite Magnetic Photocatalyst Bi5O7I/MnxZn1−xFe2O4: Hydrothermal-Roasting Preparation and Excellent Photocatalytic Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 118 ◽  
Author(s):  
Hailong Wang ◽  
Longjun Xu ◽  
Chenglun Liu ◽  
Yuan Lu ◽  
Qi Feng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Energy Gap ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
Magnetic Photocatalyst ◽  
Transmission Electron ◽  
Excellent Photocatalytic Activity ◽  
Average Recovery Rate

A new composite magnetic photocatalyst, Bi5O7I/MnxZn1−xFe2O4, prepared by a hydrothermal-roasting method was studied. The photocatalytic properties of Bi5O7I/MnxZn1−xFe2O4 were evaluated by degradation of Rhodamine B (RhB) under simulated sunlight irradiation, and the structures and properties were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible light (UV-Vis) diffuse reflectance spectra (DRS), and a vibrating sample magnetometer (VSM). The results indicated that Bi5O7I/MnxZn1−xFe2O4 was an orthorhombic crystal, which was similar to that observed for Bi5O7I. Bi5O7I/MnxZn1−xFe2O4 consisted of irregularly shaped nanosheets that were 40–60 nm thick. The most probable pore size was 24.1 nm and the specific surface area was 7.07 m2/g. Bi5O7I/MnxZn1−xFe2O4 could absorb both ultraviolet and visible light, and the energy gap value was 3.22 eV. The saturation magnetization, coercivity and residual magnetization of Bi5O7I/MnxZn1−xFe2O4 were 3.9 emu/g, 126.6 Oe, and 0.7 emu/g respectively, which could help Bi5O7I/MnxZn1−xFe2O4 be separated and recycled from wastewater under the action of an external magnetic field. The recycling experiments revealed that the average recovery rate of the photocatalyst was 90.1%, and the photocatalytic activity was still more than 81.1% after five cycles.

Photocatalytic Activity of Nitrogen-Doped Mesoporous Carbon Spheres Supporting Anatase TiO2 Prepared by a Simple Two-Step Solvothermal Approach

NANO ◽  
2015 ◽  
Vol 10 (05) ◽  
pp. 1550076 ◽  
Author(s):  
Tianjiao Bi ◽  
Jiafeng Wan ◽  
Shilin Yang ◽  
Xiujuan Yu ◽  
Fangwei Ma
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Mesoporous Carbon ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
Nitrogen Doped ◽  
Transmission Electron ◽  
Ft Ir ◽  
Light Excitation ◽  
Adsorption Desorption

Nitrogen-doped mesoporous carbon spheres (NMCSs) supporting anatase TiO 2 ( NMCSs – TiO 2) were prepared by a simple two-step solvothermal approach. The characterizations for the physicochemical properties of prepared samples under different solvothermal temperatures were carried out by X-ray diffraction (XRD) analyses, scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption–desorption (Brunauer–Emmett–Teller (BET) measurements), Fourier transform infrared (FT-IR) spectroscopy, Raman scattering and UV-Vis diffuse reflectance spectra, were combined in order to determine the crystal phase and grain size, shape, degree of mesoporous carbon incorporation, and nature of the resultant oxycarbide chemical bonding on the surface and in the bulk. The high relative photocatalytic activity of NMCSs – TiO 2 nanoparticle was evaluated through a study of the decomposition of phenol under visible-light excitation.

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