Z-Scheme over all Water Splitting on Rh/K4Nb6O17 Nanosheets Photocatalyst

2016 ◽  
Vol 99 ◽  
pp. 3-8
Author(s):  
Hsin Yu Lin ◽  
Yu Lin Ye
Keyword(s):  
Water Splitting ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Practical Importance ◽  
Proton Exchange ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray

Developing a photocatalysis system to generate hydrogen from water is a topic of great interest for fundamental and practical importance. In this study, hydrogen production by a new Z-scheme photocatalysis water splitting system was examined over Rh modified K4Nb6O17 nanosheets and Pt/WO3 photocatalysts for H2 evolution and O2 evolution with I-/IO3- electron mediator under UV light irradiation. The H2 evolution photocatalyst, Rh/K4Nb6O17 nanosheets with a slit like framework, was prepared by exfoliation of and proton exchange reaction. Pt/WO3 prepared by incipient-wetness impregnation method was used as O2 evolution photocatalyst. The catalysts were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS), and ultraviolet-visible spectroscopy (UV-vis). These catalysts characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectroscopy (UV-Vis). In this study, we developed a facile method of preparing K4Nb6O17 nanosheets containing Rh nanoparticles. Our results show that I- concentration and pH of reaction solution significantly influenced the photocatalytic activity. The combination of Rh modified K4Nb6O17 nanosheets with Pt/WO3 achieves a very high photoactivity (H2: 4240 O2: 1622 (μmol g-1 h-1)).

Platinum Reduction Study on Pt/C Electro-catalysts for PEMFC

2013 ◽  
Vol 16 (3) ◽  
pp. 141-145
Author(s):  
M.L. Hernandez-Pichardo ◽  
R. Gonzalez-Huerta ◽  
P. del Angel ◽  
E. Palacios-Gonzalez ◽  
M. Tufiño-Velazquez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Reducing Agents ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Platinum Species ◽  
Scanning Electron

Platinum reduction on Pt/C catalysts was studied on samples prepared by the impregnation method using different Pt precursors and reducing agents such as ethanol, sodium borohydride and ethanol-UV light (photo-assisted reduction), in order to compare the efficiency of the different reducing agents. The influence of the reduction level of the platinum species on the electrochemical behavior of these catalysts has been determined. The catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and linear and cyclic voltammetry. The results show that the reduction level depends mainly on the platinum precursor. Moreover, it was found that the higher electrochemical activity was found using catalysts reduced with ethanol, whereas by using NaBH4 as the reducing agent, the total reduction of the platinum precursor is very difficult in same synthesis conditions. The analysis of the XPS results shows that samples reduced with ethanol presented the lower PtOx/Pt reduction ratio.

ROOM TEMPERATURE PHOTOLUMINESCENCE OF POLYCRYSTALLINE SIC PREPARED FROM CARBON-SATURATED SI MELT

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1047-1051
Author(s):  
JIANPING MA ◽  
ZHIMING CHEN ◽  
GANG LU ◽  
MINGBIN YU ◽  
LIANMAO HANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Uv Light ◽  
X Ray Diffraction ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Composition And Structure ◽  
Light Excitation ◽  
Scanning Electron

Intense photoluminescence (PL) has been observed at room temperature from the polycrystalline SiC samples prepared from carbon-saturated Si melt at a temperature ranging from 1500 to 1650°C. Composition and structure of the samples have been confirmed by means of X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. PL measurements with 325 nm UV light excitation revealed that the room temperature PL spectrum of the samples consists of 3 luminescent bands, the peak energies of which are 2.38 eV, 2.77 eV and 3.06 eV, respectively. The 2.38 eV band is much stronger than the others. It is suggested that some extrinsic PL mechanisms associated with defect or interface states would be responsible to the intensive PL observed at room temperature.

Hydrothermal Synthesis and Photocatalytic Properties of Flower-Like CdS Nanostructures

2011 ◽  
Vol 335-336 ◽  
pp. 460-463 ◽  
Author(s):  
Hong Mei Wang ◽  
Da Peng Zhou ◽  
Yuan Lian ◽  
Ming Pang ◽  
Dan Liu
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Transmission Electron ◽  
Cds Nanostructures

Hexagonal flower-like CdS nanostructures were successfully synthesized through a facile hydrothermal method with thiourea as sulfur source. By combining the results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), the structural and morphological characterizations of the products were performed. The photocatalytic activity of CdS nanostructures had been tested by degradation of Rhodamine B (RB) under UV light compared to commercial CdS powders, which indicated that the as-syntherized CdS nanostructures exhibited enhanced photocatalytic activity for degradation of RB. The possible growth mechanism of CdS nanostructures was proposed in the end.

Synthesis of Nitrogen and Sulfur Codoped TiO2 and its Better Efficient Degradation of Organophosphorus Pesticides

2011 ◽  
Vol 183-185 ◽  
pp. 1787-1790
Author(s):  
Guang Sheng Chen ◽  
Si Yao Guo ◽  
Feng Zhang ◽  
Shi Miao Dong ◽  
Song Han
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
Degradation Rate ◽  
Uv Light ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Efficiency

N, S codoped titania with high photocatalystic properties were prepared by hydrothermal method. The resulting materials were characterized by X-ray diffraction, X-ray photoelectron spectroscopy. N, S codoped titania displayed a better degradation rate of organophosphorus pesticide under visible light irradiation. The utility of N, S codoped TiO2 as a photocatalysis over undoped titania entirely, whether the requirement for visible-light functionality, even if at low efficiency, outweighs a modest drop in the efficiency of catalysis using UV light.

Preparation of Pd/GO/Cu Electrode and Its Electrochemical Degradation for 2,4-Dichlorophenol

2020 ◽  
Vol 20 (6) ◽  
pp. 3604-3609
Author(s):  
Jian Zhang ◽  
Yuting Jiang ◽  
Bing Wang ◽  
Lanhe Zhang ◽  
Zheng Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water Environment ◽  
Constant Current ◽  
Surface Element ◽  
Impregnation Method ◽  
Electrochemical Degradation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Preparation Conditions ◽  
The Stability

Chlorinated aromatic compounds (CACs) are a class of persistent organic pollutants, which have serious damage to water environment due to their own stable structure. But a good many of CACs were abandoned because of their tremendous yields and wide applications, so it is urgent to find the effective degradation methods for CACs. The electrochemical method is supposed to be a simple, environmentally friendly and effective pathway to degrade CACs. In this paper, a Pd/GO/Cu composite electrode was prepared by a combination of impregnation method and constant current electrodeposition method, which showed good electrochemical degradation efficiency for the 2,4-dichlorophenol. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface structure, functional group composition, crystal structure and surface element valence of the electrode. Moreover, the stability of the electrode was investigated, and the preparation conditions of the electrode were optimized.

scholarly journals Borocarbonitride Layers on Titanium Dioxide Nanoribbons for Efficient Photoelectrocatalytic Water Splitting

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5490
Author(s):  
Nuria Jiménez-Arévalo ◽  
Eduardo Flores ◽  
Alessio Giampietri ◽  
Marco Sbroscia ◽  
Maria Grazia Betti ◽  
...  
Keyword(s):  
Water Splitting ◽  
Photoelectron Spectroscopy ◽  
Vapour Deposition ◽  
Electrochemical Impedance ◽  
Chemical Vapour ◽  
Photoelectrochemical Cell ◽  
Flat Band ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reflectance Measurements

Heterostructures formed by ultrathin borocarbonitride (BCN) layers grown on TiO2 nanoribbons were investigated as photoanodes for photoelectrochemical water splitting. TiO2 nanoribbons were obtained by thermal oxidation of TiS3 samples. Then, BCN layers were successfully grown by plasma enhanced chemical vapour deposition. The structure and the chemical composition of the starting TiS3, the TiO2 nanoribbons and the TiO2-BCN heterostructures were investigated by Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Diffuse reflectance measurements showed a change in the gap from 0.94 eV (TiS3) to 3.3 eV (TiO2) after the thermal annealing of the starting material. Morphological characterizations, such as scanning electron microscopy and optical microscopy, show that the morphology of the samples was not affected by the change in the structure and composition. The obtained TiO2-BCN heterostructures were measured in a photoelectrochemical cell, showing an enhanced density of current under dark conditions and higher photocurrents when compared with TiO2. Finally, using electrochemical impedance spectroscopy, the flat band potential was determined to be equal in both TiO2 and TiO2-BCN samples, whereas the product of the dielectric constant and the density of donors was higher for TiO2-BCN.

scholarly journals Structure and photocatalytic properties of sintered TiO2 nanotube arrays

2018 ◽  
Vol 50 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Jelena Vujancevic ◽  
Andjelika Bjelajac ◽  
Jovana Cirkovic ◽  
Vera Pavlovic ◽  
Endre Horvath ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Tio2 Nanotubes ◽  
Elevated Temperatures ◽  
Uv Light ◽  
Tio2 Nanotube ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Tio2 ◽  
Nanotube Films

One-dimensional (1D) TiO2 nanotubes perpendicular to the substrate were obtained by electrochemical oxidation of titanium foil in an acid electrolyte. In order to alter the crystallinity and the morphology of films the as-anodized amorphous TiO2 nanotube films were sintered at elevated temperatures. The evolution of the morphology was visualized via scanning electron microscopy (SEM), while the crystalline structure was investigated by X-ray diffraction (XRD) and Raman spectroscopy. The chemical composition was studied by X-ray photoelectron spectroscopy (XPS). The effects of crystallinity and morphology of TiO2 nanotube (NTs) films on photocatalytic degradation of methyl orange (MO) in an aqueous solution under UV light irradiation were also investigated. The TiO2 nanotubes sintered at 650?C for 30 min had the highest degree of crystallinity and exhibited the best photocatalytic activity among the studied TiO2 nanotube films.

scholarly journals Biofuel from hydrocracking of Cerbera manghas oil over Ni-Zn/HZSM-5 catalyst

2022 ◽  
Vol 47 (1) ◽  
pp. 17-39
Author(s):  
Lenny Marlinda ◽  
Danawati Hari Prajitno ◽  
Achmad Roesyadi ◽  
Ignatius Gunardi ◽  
Yustia Wulandari Mirzayanti ◽  
...  
Keyword(s):  
Batch Reactor ◽  
Hydrocarbon Composition ◽  
Absorption Spectrometry ◽  
Gas Chromatography Mass Spectrometry ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
Transportation Fuel ◽  
X Ray ◽  
Cerbera Manghas

The effects of reaction temperature on the hydrocarbon composition of biofuel produced in hydrocracking of Cerbera manghas oil with Ni-Zn/HZSM-5 catalyst were investigated. The incipient wetness impregnation method was applied to prepare the Ni-Zn/HZSM-5 catalysts. Furthermore, the properties of catalysts were measured by X-ray diffraction, atomic absorption spectrometry, and nitrogen physisorption. Hydrocracking process was carried out in Parr USA pressure batch reactor at pressure of 20 � 5 bar after flowing H2 for 1 h. The reaction with a catalyst/oil ratio of 1 g/150 mL proceeded at various temperatures of 350, 375 and 400 �C for 2 h. Gas chromatography-mass spectrometry was�used to analyze biofuel. The most abundant hydrocarbon compounds in biofuel were identified as pentadecane and heptadecane (a major diesel fuel compound) with a different amount at different reaction temperatures. It can be said that the hydrodecarboxylation/decarbonylation routes were the predominant reaction pathways and oxygen removal occurred during hydrocracking. The Cerbera manghas oil can be recommended as a promising biofeed to produce the gasoil as an alternative transportation fuel.

Pd-Only Catalyst Modified by BaO with Co- Precipitation and Impregnation Methods towards the Methanol Fuel Emission Control

2012 ◽  
Vol 581-582 ◽  
pp. 313-316
Author(s):  
Xue Qiao Zhang ◽  
Zhi Xiang Ye ◽  
Cheng Hua Xu ◽  
Ming Zhao ◽  
Yao Qiang Chen
Keyword(s):  
Co Oxidation ◽  
Photoelectron Spectroscopy ◽  
Palladium Catalysts ◽  
Active Species ◽  
Precipitation Method ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Co Precipitation

Barium oxide was introduced to modify Palladium catalysts supported on CeO2–ZrO2-La2O3-Al2O3 (CZLA) by impregnation and co-precipitation. methods. Various techniques, including X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS), were employed to characterize the physicochemical properties of BaO-modified Pd-only catalyst. Catalytic activity for methanol, CO, C3H8 and NO conversions showed that BaO-modified catalyst prepared by impregnation method exhibited the best performance for methanol, C3H8 and NO removals, while the catalyst prepared by co-precipitation method was in favor of CO oxidation. Combined with the results of XRD, H2-TPR and XPS, it is concluded that the co-existence of PdO and Pd-O-Ce active species by impregnation played an important role in the methanol, C3H8 and NO removals, while the higher dispersion of palladium and improved reducibility were mostly favorable to the CO oxidation. The conversion of NO was co-effected by tow active species and the formation of Ba2AlLaO5 mixed oxide.

scholarly journals Enhanced Solar Water Splitting Performance of 50-100 nm Pore Sized TiO2 Nanotubes

2019 ◽  
Vol 31 (3) ◽  
pp. 559-565
Author(s):  
K. Kathiresan ◽  
P. Elangovan ◽  
M.S.S. Saravanakumaar
Keyword(s):  
Water Splitting ◽  
Photoelectron Spectroscopy ◽  
Hydrofluoric Acid ◽  
Tio2 Nanotubes ◽  
Uv Light ◽  
Photoelectrochemical Performance ◽  
X Ray ◽  
Solar Water ◽  
Solar Water Splitting ◽  
The Impact

Herein, we report the fabrication of titanium dioxide nanotubes via anodization technique through with and without hydrofluoric acid . The impact of hydrofluoric acid followed by annealing effect on TiO2 nanotubes for the solar water splitting performance was examined. Prepared TiO2 samples exhibited a diameter of about 50 to 100 nm sized nanotubes and hierarchical structures and they subjected to annealing. Synthesis and annealing effects on chemical, physical and photoelectrochemical water splitting activity of TiO2 samples were scrutinized. The crystalline nature, structure and surface morphologies of prepared TiO2 photocatalysts were explored by X-ray diffraction, scanning electron microscope, and the oxidation states of both titanium and oxygen was determined by X-ray photoelectron spectroscopy. As a consequence, after annealing at 500 ºC, TiO2 thin films treated with hydrofluoric acid solution (HF-TiO2) were found to exhibit a remarkable photoelectrochemical performance than bare TiO2 nanotubes under UV light irradiation. Moreover, the mechanistic insights acquired in the current research would be beneficial to design a novel and highly efficient photocatalyst for solar water splitting systems.

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