scholarly journals Visible-Light Activation of Photocatalytic for Reduction of Nitrogen to Ammonia by Introducing Impurity Defect Levels into Nanocrystalline Diamond

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4559
Author(s):  
Rui Su ◽  
Zhangcheng Liu ◽  
Haris Naeem Abbasi ◽  
Jinjia Wei ◽  
Hongxing Wang
Keyword(s):  
Visible Light ◽  
Wavelength Region ◽  
Average Diameter ◽  
High Energy ◽  
Nitrogen Vacancy ◽  
Energy Conditions ◽  
Nitrogen Doped ◽  
Single Crystal Diamond ◽  
Defect Levels ◽  
Charge States

Nitrogen impurity has been introduced in diamond film to produce a nitrogen vacancy center (NV center) toward the solvated electron-initiated reduction of N2 to NH3 in liquids, giving rise to extend the wavelength region beyond the diamond’s band. Scanning electron microscopy and X-ray diffraction demonstrate the formation of the nanocrystalline nitrogen-doped diamond with an average diameter of ten nanometers. Raman spectroscopy and PhotoLuminescence (PL) spectrum show characteristics of the NV0 and NV− charge states. Measurements of photocatalytic activity using supraband (λ < 225 nm) gap and sub-band gap (λ > 225 nm) excitation show the nitrogen-doped diamond significantly enhanced the ability to reduce N2 to NH3 compared to the polycrystalline diamond and single crystal diamond (SCD). Our results suggest an important process of internal photoemission, in which electrons are excited from negative charge states into conduction band edges, presenting remarkable photoinitiated electrons under ultraviolet and visible light. Other factors, including transitions between defect levels and processes of reaction, are also discussed. This approach can be especially advantageous to such as N2 and CO2 that bind only weakly to most surfaces and high energy conditions.

Visible-Light Induced Photocatalytic Activity of Vanadium and Nitrogen Co-Doped SrTiO3

2009 ◽  
Vol 147-149 ◽  
pp. 851-855 ◽  
Author(s):  
Jin Shu Wang ◽  
Hui Li ◽  
Hong Yi Li ◽  
Shu Yin ◽  
Tsugio Sato
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
High Energy ◽  
Nitrogen Doped ◽  
Near Ultraviolet ◽  
Ultraviolet Range ◽  
Photocatalytic Activities ◽  
Milling Method ◽  
Co Doped ◽  
Visible Light Photocatalytic

Vanadium doped, nitrogen doped, and vanadium and nitrogen co-doped SrTiO3 powders with size of 20-30 nm in diameter were prepared by high energy milling method respectively. It was found that compared with those of pure SrTiO3, the photocatalytic activities of these three doped SrTiO3 samples for decomposing NO under visible light (λ>400 nm) and near ultraviolet light (λ>290 nm) irradiation were improved, and the co-doped sample exhibited the highest photocatalytic activity. 43.2% NO could be eliminated under the irradiation of light with wavelength larger than 400nm, about 3 times higher than that by pure SrTiO3. The photocatalytic activity of this sample near ultraviolet range is about 1.7 times higher than that of pure SrTiO3. The high visible light photocatalytic activity of this substance may be due to the high visible light absorption and large specific surface area.

scholarly journals High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Vladimir Yu. Osipov ◽  
Fedor M. Shakhov ◽  
Kirill V. Bogdanov ◽  
Kazuyuki Takai ◽  
Takuya Hayashi ◽  
...  
Keyword(s):  
Polycrystalline Diamond ◽  
Particle Beam ◽  
Production Method ◽  
High Energy ◽  
Nitrogen Vacancy ◽  
High Energy Particle ◽  
Paramagnetic Resonance ◽  
Precursor Material ◽  
Mean Size ◽  
Characteristic Features

Abstract We demonstrate a high-pressure, high-temperature sintering technique to form nitrogen-vacancy-nitrogen centres in nanodiamonds. Polycrystalline diamond nanoparticle precursors, with mean size of 25 nm, are produced by the shock wave from an explosion. These nanoparticles are sintered in the presence of ethanol, at a pressure of 7 GPa and temperature of 1300 °C, to produce substantially larger (3–4 times) diamond crystallites. The recorded spectral properties demonstrate the improved crystalline quality. The types of defects present are also observed to change; the characteristic spectral features of nitrogen-vacancy and silicon-vacancy centres present for the precursor material disappear. Two new characteristic features appear: (1) paramagnetic substitutional nitrogen (P1 centres with spin ½) with an electron paramagnetic resonance characteristic triplet hyperfine structure due to the I = 1 magnetic moment of the nitrogen nuclear spin and (2) the green spectral photoluminescence signature of the nitrogen-vacancy-nitrogen centres. This production method is a strong alternative to conventional high-energy particle beam irradiation. It can be used to easily produce purely green fluorescing nanodiamonds with advantageous properties for optical biolabelling applications.

Nitrogen-Doped Multi-Channel Carbon Nanofibers Incorporated with Nickel Nanoparticles as Multifunctional Modification of Separator for Ultra Stable Li-S Batteries

2021 ◽  
Author(s):  
Zhikang Wang ◽  
Guiqiang Cao ◽  
Da Bi ◽  
Tian-Xiong Tan ◽  
Qingxue Lai ◽  
...  
Keyword(s):  
Nickel Nanoparticles ◽  
Specific Capacity ◽  
High Energy ◽  
High Energy Density ◽  
Storage Device ◽  
Energy Storage Device ◽  
High Specific Capacity ◽  
Nitrogen Doped ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

Lithium-Sulfur batteries have been regarded as the most promising electrochemical energy storage device in consideration of their satisfactory high specific capacity and high energy density. However, the inferior conversion efficiency...

scholarly journals Diverse floodplain deposits of reworked loess in a monsoon climate (Hanzhong Basin, central China)

2021 ◽  
pp. 1-17
Author(s):  
Jef Vandenberghe ◽  
Xun Yang ◽  
Xianyan Wang ◽  
Shejiang Wang ◽  
Huayu Lu
Keyword(s):  
Soil Formation ◽  
High Energy ◽  
Central China ◽  
Energy Conditions ◽  
Middle Pleistocene ◽  
Sedimentary Sequences ◽  
Varied Intensity ◽  
Floodplain Deposits ◽  
Flooding Events ◽  
Floodplain Sediments

Abstract This paper describes an assemblage of diverse floodplain facies of reworked loess (facies b, c) in a Middle Pleistocene monsoonal setting of the Hanzhong Basin, central China. The vertical and lateral sedimentary sequences show changing energy conditions. Apart from the highest energy in the channel facies (facies a), a relatively high energy floodplain environment (facies b) prevailed in waterlogged conditions, with small, laterally migrating (sub)channels. Facies b generally interfingers with aggrading horizontal sheets of overbank deposits in alluvial pools and swamps in a floodplain with much lower energy (facies c), in which phases of stability (soil formation) occasionally interrupted overbank deposition. Reworked loess forms the main part of the floodplain deposits. The paleosols are considered to have been formed under low hydrodynamic conditions in an interglacial environment. These interglacial conditions follow the commonly assumed glacial conditions of channel facies a. The sedimentary successions in the floodplain show a recurrent composition and cyclicity between wet and dry floodplain sedimentation terminated by stability with soil formation. The cyclic rhythm of stacked high- and low-energy floodplain sediments is attributed to varied intensity of different hydrodynamic flooding events that may have been due to changing monsoonal rainfall or simple intrinsic fluvial behavior.

Nitrogen-doped SiO2–HNb3O8 for rhodamine B photodegradation under visible light

2011 ◽  
Vol 509 (21) ◽  
pp. 6252-6256 ◽  
Author(s):  
Xiukai Li ◽  
Huiqi Pan ◽  
Qingsong Hu ◽  
Chi Zhang
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Nitrogen Doped

Enhanced H2Generation of Au-Loaded, Nitrogen-Doped TiO2Hierarchical Nanostructures under Visible Light

2013 ◽  
Vol 1 (1) ◽  
pp. 1300018 ◽  
Author(s):  
Brundabana Naik ◽  
Sun Mi Kim ◽  
Chan Ho Jung ◽  
Song Yi Moon ◽  
Sang Hoon Kim ◽  
...  
Keyword(s):  
Visible Light ◽  
Nitrogen Doped
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