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 Significantly Enhanced Aqueous Cr(VI) Removal Performance of Bi/ZnO Nanocomposites via Synergistic Effect of Adsorption and SPR-Promoted Visible Light Photoreduction

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 426 ◽  
Author(s):  
Xiaoya Yuan ◽  
Zijuan Feng ◽  
Jianjun Zhao ◽  
Jiawei Niu ◽  
Jiasen Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Synergistic Effect ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray ◽  
Enhanced Absorption ◽  
Bismuth Nanoparticles ◽  
Effective Transfer

Bismuth nanoparticles (BiNPs) and Zinc Oxide photocatalysts (BiNPs/ZnO) with different Bi loadings were successfully prepared via a facile chemical method. Their morphology and structure were thoroughly characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis (Ultraviolet-Visible) diffuse reflectance spectroscopy (DRS), photoluminescence spectra (PL), and electrochemical impedance spectroscopy (EIS). The results showed that a modification of hexagonal wurtzite-phase ZnO nanoparticles with Bi is achievable with an intimate interfacial interaction within its composites. The performance of the photocatalytic Cr(VI) removal under visible light irradiation indicated that BiNPs/ZnO exhibited a superior removal performance to bare ZnO, Bi, and the counterpart sample prepared using a physical mixing method. The excellent performance of the BiNPs/ZnO photocatalysts could be ascribed to the synergistic effect between the considerable physical Cr (VI) adsorption and enhanced absorption intensity in the visible light region, due to the surface plasmon resonance (SPR) as well as the effective transfer and separation of the photogenerated charge carriers at the interface.

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 Visible Light-Driven Mn-MoS2/rGO Composite Photocatalysts for the Photocatalytic Degradation of Rhodamine B

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Thi Thuy Trang Phan ◽  
Thanh Tam Truong ◽  
Ha Tran Huu ◽  
Le Tuan Nguyen ◽  
Van Thang Nguyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Resonance Spectroscopy ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Composite Photocatalysts

The n%Mn-MoS2/rGO (labeled as n%MMS/rGO, where n% = Mn/(Mn + Mo) in mol) composites were successfully prepared by a facile hydrothermal method from the Mn-MoS2 (MMS) and rGO precursors, in which the MMS was obtained by a facile one-step calcination of (NH4)6Mo7O24·4H2O, (NH2)2CS, and Mn(CH3COO)2·4H2O as precursors in N2 gas at 650°C. The samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron paramagnetic resonance spectroscopy (EPR), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS), which indicates the composites containing nanosheets of Mn-MoS2 and rGO components. The photocatalytic activities of the n%MMS/rGO composite photocatalysts were evaluated through the photodegradation of rhodamine B (RhB) under the visible light irradiation. The enhancement in the photocatalytic performance of the achieved composites was attributed to the synergic effect of Mn doping and rGO matrix. The investigation of photocatalytic mechanism was also conducted.

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.

scholarly journals Fabrication of Bi-DopedTiO2Spheres with Ultrasonic Spray Pyrolysis and Investigation of Their Visible-Light Photocatalytic Properties

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Jianhui Huang ◽  
Wahkit Cheuk ◽  
Yifan Wu ◽  
Frank S. C. Lee ◽  
Wingkei Ho
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Spray Pyrolysis ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Ultrasonic Spray Pyrolysis ◽  
X Ray ◽  
Ultrasonic Spray ◽  
Doped Titania

Bismuth-doped TiO2submicrospheres were synthesized by ultrasonic spray pyrolysis. The prepared bismuth-doped titania was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). Aqueous photocatalytic activity was evaluated by the decomposition of methyl orange under visible-light irradiation. The results indicate that doping of bismuth remarkably affects the phase composition, crystal structure, and the photocatalytic activity. The sample with 2% Bi exhibits the optimum photocatalytic activity.

scholarly journals Fabrication of Mo+N-Codoped TiO2Nanotube Arrays by Anodization and Sputtering for Visible Light-Induced Photoelectrochemical and Photocatalytic Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Min Zhang ◽  
Dandan Lu ◽  
Guotian Yan ◽  
Juan Wu ◽  
Jianjun Yang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Photocurrent Density ◽  
Electrochemical Anodization ◽  
Nanotube Arrays ◽  
Step Method ◽  
X Ray ◽  
New States

Mo,N-codoped TiO2nanotube arrays (TNAs) were fabricated by a two-step method consisting of electrochemical anodization and subsequent magnetron sputtering of Mo. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that the Mo,N-codoped TiO2nanotube arrays exhibited higher visible light absorbance and remarkably enhanced photocurrent density and photocatalytic activity compared with single N-doped TiO2. The highly efficient photoelectrochemical and photocatalytic activity is associated with the codoping effect between Mo and N, which plays a key role in producing new states, narrowing the bandgap, and reducing the recombination thereby effectively improving the visible light absorption and photocatalytic activity of TNAs.

scholarly journals Design and fabrication of Ag3VO4/g-C3N4 heterostructure photocatalyst for enhanced visible light degradation of various organic pollutants

2021 ◽  
Author(s):  
N Sujatha ◽  
M Meenachi ◽  
S Mohammed Harshulkhanb ◽  
H.H Hegazy
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Irradiation ◽  
X Rays ◽  
Hydrothermal Route ◽  
X Ray ◽  
Visible Light Degradation

Abstract In later years, numerous viable photocatalysts have been created in order to illuminate the issues of natural toxins. In this work, heterostructured photocatalysts Ag3VO4/g-C3N4 were prepared by effortless hydrothermal route in order to anchor Ag3VO4 on the surface of the g-C3N4 nanosheets. The prepared samples were fairly characterized using X-ray diffraction (XRD), Energy dispersive analysis of X-rays (EDAX), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence, and X-ray photoelectron spectroscopy (XPS) techniques. The photocatalytic activity of the samples was evaluated by degrading malachite green (MG) and 2,4 dimethyl phenol (DMP) in aqueous solution under visible light irradiation. Compared with Ag3VO4 and g-C3N4, the heterojuncted photocatalyst 50 wt% Ag3VO4/g-C3N4 exhibits the best activity such as high degradation efficiency (99%), high apparent constant (0.0923 min− 1) and long term stability towards DMP under visible light irradiation. The development of a phase scheme heterojunction between Ag3VO4 and g-C3N4 improved the photocatalytic efficiency of Ag3VO4/g-C3N4 composites. Furthermore, the porous structure of g-C3N4 and the effect of Ag surface plasmon resonance (SPR) speed up the isolation and transfer of electron-hole pairs, reducing the likelihood of recombination.

Improved visible-light photocatalytic activity of sodium tantalum oxide via biomass-derived silk fibroin doping

2018 ◽  
Vol 89 (7) ◽  
pp. 1332-1339
Author(s):  
Yehua Sun ◽  
Yuzhuo Luo ◽  
Yaofeng Zhu ◽  
Yaqin Fu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Silk Fibroin ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray ◽  
Transmission Electron

Biomass-derived silk fibroin (SF)-doped NaTaO3 catalysts were successfully synthesized by a simple hydrothermal process using SF as the dopant. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) analyses. The samples were tested as photocatalysts in the degradation of methylene blue under UV and visible light. XRD results showed the monoclinic structure of NaTaO3 lacking significant structural changes after anion doping. SEM and TEM images revealed the nanocubic morphology of the samples, the crystal particle sizes of which were about 100–300 nm. The XPS spectrum showed the peak of Ta4p3&N1s, indicating the combination of N and Ta. The UV-vis DRS results of the samples revealed a cut-off edge that red shifted from 315 nm of the pure NaTaO3 to 324 nm of the SF-doped counterpart. SF doping helped narrow the band gap and rendered the prepared sample sensitive to visible light. Under UV and visible-light irradiation, SF-doped NaTaO3 exhibited higher photocatalytic activity than that the undoped compound. SF-doped NaTaO3 samples also exhibited excellent stability during the recycling photocatalytic process.

scholarly journals Facile Synthesis of Heterojunctioned ZnO/Bi2S3 Nanocomposites for Enhanced Photocatalytic Reduction of Aqueous Cr(VI) under Visible-Light Irradiation

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 624 ◽  
Author(s):  
Xiaoya Yuan ◽  
Xue Wu ◽  
Zijuan Feng ◽  
Wen Jia ◽  
Xuxu Zheng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Structured Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Facile Solvothermal Method

Heterojunctioned ZnO/Bi2S3 nanocomposites were prepared via a facile solvothermal method. The obtained photocatalysts were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), and Photoelectrochemical and Photoluminescence spectroscopy (PL), respectively. The results showed that ZnO/Bi2S3 composites exhibited the sandwiched-like structure, where ZnO nanoparticles were randomly embedded between Bi2S3 nanoflakes. The performance of photocatalytic Cr(VI) reduction under visible light indicated that ZnO/Bi2S3 composites exhibited high-efficiency photocatalytic activity in comparison with either Bi2S3 or ZnO. The 5%-ZnO/Bi2S3 photocatalyst removed 96% of Cr(VI) within 120 min at 20 mg/L initial concentration of Cr(VI). The enhanced performance of ZnO/Bi2S3 photocatalysts could be ascribed to the increased light harvesting and the effective separation and transfer of the photogenerated charge carriers across the heterojunction interface of the ZnO/Bi2S3 composite. This work could pave the way for the design of new hetero-structured materials and has great potential in environmental remediation.

Visible light response, electrical transport, and amorphization in compressed organolead iodine perovskites

Nanoscale ◽  
2016 ◽  
Vol 8 (22) ◽  
pp. 11426-11431 ◽  
Author(s):  
Tianji Ou ◽  
Jiejuan Yan ◽  
Chuanhai Xiao ◽  
Wenshu Shen ◽  
Cailong Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Impedance Spectroscopy ◽  
Visible Light ◽  
Electrical Transport ◽  
Light Response ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Response ◽  
Transmission Electron

This study presents how pressure tunes the properties of CH3NH3PbI3nanorods by photocurrent, impedance spectroscopy, X-ray diffraction, and transmission electron microscopy measurements.

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