Oxidative removal of As(III) by polyacrylonitrile@Ag-Ag2O/schwertmannite nanofiber under visible light

2022 ◽  
pp. 152808372110569
Author(s):  
Jing Han ◽  
Hai-Tao Ren ◽  
Ting-Ting Li ◽  
Bing-Chiuan Shiu ◽  
Yong-Gui Li ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Light Response ◽  
Precipitation Reaction ◽  
Transmission Electron Microscopy Analysis ◽  
X Ray ◽  
Oxidative Removal ◽  
Electron Microscopy Analysis ◽  
New Material

Visible light response PAN@Ag-Ag2O/Sch (PAN@AS, schwertmannite and polyacrylonitrile abbreviated as Sch and PAN) nanofibers with different mass ratios were synthesized by electrospinning technology and pH-induced precipitation reaction. X-Ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy analysis showed that the formation of Ag-Ag2O/Sch heterojunction and Ag-Ag2O nanoparticles were evenly distributed on the surface of Sch. The prepared nanofibers have high oxidative removal performance for As(III) under visible light. In the [email protected] system, the total As removal percent can reach 90.96% after 120 min irradiation at pH 4.0. The scavenger experiments confirmed that the main active substances of the [email protected] system were h+ and •OH. The high oxidation and removal performance of the [email protected] composite for As(III) was attributed to the effective separation of photogenerated electron-hole pairs and high adsorption capacity of Sch for As under acidic conditions. This research provides a new material for the oxidation and removal of pollutants in water [such as As(III)] and also provides a research basis for the preparation of recyclable photocatalysts.

One-Pot Hydrothermal Synthesis of Sulfur-Doped SnO2 Nanoparticles and their Enhanced Photocatalytic Properties

NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650035 ◽  
Author(s):  
Lin Ma ◽  
Limei Xu ◽  
Xuyao Xu ◽  
Xiaoping Zhou ◽  
Lingling Zhang
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Sno2 Nanoparticles ◽  
Light Response ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Light Region ◽  
Vis Spectroscopy

Sulfur-doped SnO2 nanoparticles with ultrafine sizes have been successfully prepared by a one-pot hydrothermal method. The obtained samples are characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM), thermogravimetric (TG), analyzer UV-Vis spectroscopy, photoluminescence (PL) and electrochemical impedance spectroscopy (EIS). The experimental results indicate that the doping level of sulfur element as well as the bandgaps of SnO2 can be controlled to a certain extent by varying the amount of L-cysteine (L-cys). When evaluated as photocatalysts in the degradation of rhodamine B (RhB) and reduction of Cr(VI) under visible light region, the resultant sulfur-doped SnO2 nanoparticles demonstrate obviously enhanced photocatalytic activities due to the markedly improved visible light response and effective separation of the photo-generated electron–hole pairs.

Metal ion and N co-doped TiO2 as a visible-light photocatalyst

2004 ◽  
Vol 19 (7) ◽  
pp. 2100-2108 ◽  
Author(s):  
Yoshiaki Sakatani ◽  
Hiroyuki Ando ◽  
Kensen Okusako ◽  
Hironobu Koike ◽  
Jun Nunoshige ◽  
...  
Keyword(s):  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Light Response ◽  
Complex Method ◽  
Visible Light Photocatalyst ◽  
X Ray ◽  
Visible Light Response ◽  
Spin Resonance ◽  
Photocatalytic Activities

Powders of TiO2 doped with a metal ion and N species were prepared by a polymerized complex method and the visible-light photocatalytic activities of the products are investigated. Of the metal ions studied (K+, Ca2+, Sr2+, Ba2+, Nb5+, Fe3+, Zn2+, and Al3+), the photocatalyst prepared with Sr2+ exhibits the highest activity for acetaldehyde decomposition under visible-light irradiation. Results obtained from x-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR) analyses suggest that the doped N species reside at interstitial lattice positions in the catalyst. It was also found by XPS and ESR measurements that the doped N species combine with lattice oxygen to give rise to a paramagnetic property. The visible-light response of the catalyst is driven by the formation of paramagnetic N species at interstitial positions in the TiO2 lattice.

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 Photocatalytic performance of Ag2S/ZnO/ZnS nanocomposites with high visible light response prepared via microwave-assisted hydrothermal two-step method

2018 ◽  
Vol 78 (8) ◽  
pp. 1802-1811 ◽  
Author(s):  
Jiwei Huang ◽  
Changlong Yang ◽  
Qiang Song ◽  
Dongxue Liu ◽  
Li Li
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Response ◽  
Light Sources ◽  
Step Method ◽  
X Ray ◽  
Microwave Assisted ◽  
Visible Light Response

Abstract A series of different ratios of Ag2S/ZnO/ZnS nanocomposites with visible light response were prepared by a microwave-assisted hydrothermal two-step method, whose composition, crystalline structure, morphology and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis/DRS), photoluminescence spectrum (PL), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and N2 adsorption–desorption measurements. Results showed that as-composites mainly consisted of ZnS crystal phase, whose grain size increased obviously compared with non Ag2S samples. At the same time, due to the introduction of narrow band gap Ag2S, the synthesized composite can effectively increase the visible optical absorption of ZnO/ZnS composites. Among them, 1% Ag2S/ZnO/ZnS showed a mixed structure of nano-line and nano-particle, of which BET value increased significantly, and the morphology was more excellent. Photocatalytic activities of a series of Ag2S/ZnO/ZnS composites under different light sources were studied using methyl orange as a model molecule, and 1% Ag2S/ZnO/ZnS was taken as the best one. Meanwhile, 1% Ag2S/ZnO/ZnS also showed a good degradation effect on other dyes with different structures, and its degradation efficiency did not change significantly after three cycles, showing certain stability. In addition, composites with Ag2S loading of 1% possessed the highest hydrogen production ability of photolysis water, indicating that the introduction of Ag2S had significantly enhanced the catalytic performance.

scholarly journals Enhanced Visible Light Driven Photocatalytic Behavior of BiFeO3/Reduced Graphene Oxide Composites

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 526 ◽  
Author(s):  
Yun-hui Si ◽  
Yu Xia ◽  
Shao-ke Shang ◽  
Xin-bo Xiong ◽  
Xie-rong Zeng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Performance ◽  
Hydrothermal Process ◽  
Photogenerated Electron ◽  
Visible Absorption ◽  
X Ray ◽  
Reduced Graphene

BiFeO3/Reduced Graphene Oxide (BFO/RGO) composites have been fabricated by a simple hydrothermal method. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman, and X-ray photoelectron spectroscopy (XPS) analysis reveal that graphene oxide was reduced in hydrothermal process and BFO/RGO composites were successfully synthesized. UV-visible absorption and photoluminescence properties show that the introduction of RGO can effectively reduce the recombination of photogenerated electron and hole pairs. Compared to the pristine BFO, the photocatalytic performance of BiFeO3 Graphene Oxide (BGO) composites is enhanced for the degradation of Methylene blue (MB) solution under visible light irradiation, and the result shows that the optimal amount of Graphene Oxide (GO) in the composites is 60 mg (BGO60). The excellent photocatalytic performance is mainly ascribed to improved light absorption, increased reactive sites, and the low recombination rate of electron-hole pairs. This work can provide more insights into designing advanced photocatalysts for wastewater treatment and environmental protection.

Preparation and Photocatalytic Activity of Yellow Titania

2013 ◽  
Vol 743-744 ◽  
pp. 849-856 ◽  
Author(s):  
Lin Li ◽  
Sheng Qi Xi ◽  
Yang Nan Xing ◽  
Fei Hu Shang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Light Response ◽  
Yellow Powder ◽  
X Ray ◽  
Titania Powder ◽  
Light Yellow ◽  
Transmission Electron

Titania powder was prepared by a sol-gel method and heat-treatment (HT). The morphology and structure of the titania powder were characterized by X-ray diffraction (XRD), differential thermal analysis, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of powder was investigated using methyl orange as target compound. Colour changing of powder was due to colour centers form. Under visible light, yellow powder showed the better photocatalytic activity than P25 powder and its visible light response was expanded. Preparation of yellow powder lowered conventional calcinations temperature obviously.

SYNTHESIS OF MONODISPERSE Mn3O4 NANOCRYSTALS

2009 ◽  
Vol 08 (03) ◽  
pp. 281-283 ◽  
Author(s):  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR
Keyword(s):  
Photoelectron Spectroscopy ◽  
Average Diameter ◽  
Binding Energies ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
20 Nm

Mn3O4 nanocrystals have been prepared using [bis(2-hydroxyacetophenato)manganese(II)] as precursor. Transmission electron microscopy analysis demonstrated nanocrystals Mn3O4 with an average diameter of about 20 nm. The structural study by X-ray diffraction indicates that these nanocrystals have pure tetragonal phase. The phase pure samples were characterized using X-ray Photoelectron Spectroscopy for Mn 2p level. The values of binding energies are consistent with the relative values reported in the literature.

scholarly journals Growth of g-C3N4Layer on Commercial TiO2for Enhanced Visible Light Photocatalytic Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Min Fu ◽  
Jiazhen Liao ◽  
Fan Dong ◽  
Hongmei Li ◽  
Hongyan Liu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Weight Ratio ◽  
Photocatalytic Property ◽  
Photogenerated Electron ◽  
Cost Effective ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Novel visible light photocatalytic graphitic carbon nitride/TiO2(g-C3N4/TiO2) composite samples were synthesized by heating mixtures of melamine and commercial TiO2(TO) at different weight ratios. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), and UV-visible diffused reflectance spectroscopy (UV-vis DRS). Characterization confirms formation of nanocomposites of g-C3N4/TiO2. At the optimized precursor weight ratio (melamine:mTiO2=2.5), the samples exhibited highest adsorption capacity and visible light photocatalytic activity, measured by degradation of methylene blue (MB). Under visible light irradiation, the excited electrons on the surface of g-C3N4transfer easily to the conduction band (CB) of TiO2via the well-built heterojunction. The g-C3N4/TiO2nanocomposites exhibit enhanced visible light catalytic activity due to increased visible light adsorption and effective separation of photogenerated electron-hole pairs. These g-C3N4/TiO2nanocomposites could find broad applicability in environmental protection due to their excellent visible light photocatalytic property and facile, cost-effective preparation process.

scholarly journals Low Temperature Oxidation of Carbon Monoxide over Mesoporous Au-Fe2O3Catalysts

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Abdulmohsen Ali Alshehri ◽  
Katabathini Narasimharao
Keyword(s):  
Thermal Treatment ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Specific Surface Area ◽  
Precipitation Method ◽  
Transmission Electron Microscopy Analysis ◽  
Temperature Oxidation ◽  
X Ray ◽  
Transmission Electron ◽  
Electron Microscopy Analysis

Low temperature active and stable mesoporous Au (0.1, 0.2, 0.5, and 1.0 wt.%) supportedα-Fe2O3catalysts were prepared via deposition-precipitation method. The H2-pretreated catalyst with 0.5 wt.% Au loading offered CO conversion of 100% at 323 K and showed continual activity for at least 120 h. X-ray diffraction and transmission electron microscopy analysis indicate that Au species were highly dispersed as nanoparticles (20–40 nm) on the surface ofα-Fe2O3support even after thermal treatment at 773 K. The N2-physisorption measurements show that the synthesizedα-Fe2O3support and Au-Fe2O3nanocomposites possessed mesopores with high specific surface area of about 158 m2 g−1. X-ray photoelectron spectroscopy and H2-TPR results reveal that the Au species exist in metallic and partially oxidized state due to strong interaction with the support. Effective Au-Fe2O3interaction resulted in a high activity for Au nanoparticles, locally generated by the thermal treatment at 773 K in air.

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