Development of a nitrogen-doped 2D material for tribological applications in the boundary-lubrication regime

The present paper describes a facile synthesis method for nitrogen-doped reduced graphene oxide (N-rGO) and the application of N-rGO as an effective additive for improving the tribological properties of base oil. N-rGO has been characterized by different characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. N-rGO-based nanolubricants are prepared and their tribological properties are studied using a four-ball tester. The nanolubricants show excellent stability over a period of six months and a significant decrease in coefficient of friction (25%) for small amounts of N-rGO (3 mg/L). The improvement in tribological properties can be attributed to the sliding mechanism of N-rGO accompanied by the high mechanical strength of graphene. Further, the nanolubricant is prepared at large scale (700 liter) and field trials are carried out at one NTPC thermal plant in India. The implementation of the nanolubricant in an induced draft (ID) fan results in the remarkable decrease in the power consumption.

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Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽

10.3390/molecules26030661 ◽

2021 ◽

Vol 26 (3) ◽

pp. 661

Author(s):

Zhiwei Ying ◽

Xinwei Chen ◽

He Li ◽

Xinqi Liu ◽

Chi Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Methylene Blue ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

Urban Pollution ◽

Maximum Adsorption Capacity ◽

One Pot ◽

Average Pore ◽

X Ray ◽

Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

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Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽

10.3390/catal10060640 ◽

2020 ◽

Vol 10 (6) ◽

pp. 640

Author(s):

Hideaki Sasaki ◽

Keisuke Sakamoto ◽

Masami Mori ◽

Tatsuaki Sakamoto

Keyword(s):

Electron Microscopy ◽

Solid Solution ◽

Solid Solutions ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Co Precipitation ◽

Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

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Photocatalytic degradation of deoxynivalenol over dendritic-like α-Fe2O3 under visible light irradiation

Toxins ◽

10.3390/toxins11020105 ◽

2019 ◽

Vol 11 (2) ◽

pp. 105 ◽

Cited By ~ 14

Author(s):

Huiting Wang ◽

Jin Mao ◽

Zhaowei Zhang ◽

Qi Zhang ◽

Liangxiao Zhang ◽

...

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Photocatalytic Degradation ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Synthesis Method ◽

Light Irradiation ◽

Trichothecene Mycotoxin ◽

X Ray

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium, which is a trichothecene mycotoxin. As the main mycotoxin with high toxicity, wheat, barley, corn and their products are susceptible to contamination of DON. Due to the stability of this mycotoxin, traditional methods for DON reduction often require a strong oxidant, high temperature and high pressure with more energy consumption. Therefore, exploring green, efficient and environmentally friendly ways to degrade or reduce DON is a meaningful and challenging issue. Herein, a dendritic-like α-Fe2O3 was successfully prepared using a facile hydrothermal synthesis method at 160 °C, which was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It was found that dendritic-like α-Fe2O3 showed superior activity for the photocatalytic degradation of DON in aqueous solution under visible light irradiation (λ > 420 nm) and 90.3% DON (initial concentration of 4.0 μg/mL) could be reduced in 2 h. Most of all, the main possible intermediate products were proposed through high performance liquid chromatography-mass spectrometry (HPLC-MS) after the photocatalytic treatment. This work not only provides a green and promising way to mitigate mycotoxin contamination but also may present useful information for future studies.

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Synthesis and tribological properties of nanogrease

Industrial Lubrication and Tribology ◽

10.1108/ilt-08-2017-0228 ◽

2018 ◽

Vol 70 (3) ◽

pp. 512-518 ◽

Cited By ~ 6

Author(s):

Alaa Mohamed ◽

Mohamed Hamdy ◽

Mohamed Bayoumi ◽

Tarek Osman

Keyword(s):

Electron Microscopy ◽

Tribological Properties ◽

Power Efficiency ◽

New Technologies ◽

Mechanical Equipment ◽

Content Type ◽

Base Oil ◽

X Ray ◽

Transmission Electron ◽

Steel Balls

Purpose To enhance the tribological properties of nanogrease, one of the new technologies was used to synthesize a nanogrease having carbon nanotubes (CNTs) nanoparticles (NPs) with different concentrations. The microstructures of the synthesized NPs were characterized and evaluated by x-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Tribological properties of the nanogrease were evaluated using a four-ball tester. The worn surface of four steel balls was investigated by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). Design/methodology/approach Grease was dissolved in chloroform (10 Wt.%), at 25 °C for 1 h. In parallel, functionalized CNTs with different volume concentrations (0.5, 1, 2 and 3 Wt.%) were dispersed in N, N-dimethylformamide. The mixture was stirred for 15 min and then sonicated (40 kHz, 150 W) for 30 min. After that, the mixture was added to the grease solution and magnetically stirred for 15 min and then sonicated for 2 h. Findings The results suggested that CNTs can enhance the antiwear and friction properties of nanogrease at 0.5 Wt.% CNTs to about 57 and 48 per cent, respectively. In addition, the weld load of the base oil containing 0.5 Wt.% CNTs was improved by 17 per cent compared with base grease. Originality/value This work describes the inexpensive and simple fabrication of nanogrease for improving the properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.

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Large Scale Preparation of β-AgVO3 Nanowires Using a Novel Sonochemical Route

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.102 ◽

2008 ◽

Vol 8 (6) ◽

pp. 3203-3207 ◽

Cited By ~ 10

Author(s):

Changjie Mao ◽

Xingcai Wu ◽

Jun-Jie Zhu

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Lithium Ion Batteries ◽

Photoelectron Spectroscopy ◽

Large Scale ◽

Lithium Ion ◽

Gravimetric Analysis ◽

X Ray ◽

Transmission Electron ◽

Scanning Transmission

A large number of β-AgVO3 nanowires with diameter of 30–60 nm, and length of 1.5–3 μm have been successfully synthesized by a simple and facile low-temperature sonochemical route. The morphologies and structures of the nanowires were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning transmission electron microscopy (SEM), and thermal gravimetric analysis (TGA). Cyclic voltammetry and charge–discharge experiments were applied to characterize the electrochemical properties of the nanowires as cathode materials for lithium-ion batteries. In the initial discharge and charge process, the as-prepared β-AgVO3 nanowires showed the initial charge and discharge capacities of 69 and 102 (mAh)/g, respectively. It is anticipated that the β-AgVO3 nanostructures are promising cathode candidates in the application of primary lithium-ion batteries.

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Nitrogen Doped and Functionalized Carbon Materials as Supports for Catalysts in Electro-Oxidation of Methanol

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.93.41 ◽

2014 ◽

Vol 93 ◽

pp. 41-49 ◽

Cited By ~ 2

Author(s):

M.J. Lázaro ◽

C. Alegre ◽

M.J. Nieto-Monge ◽

D. Sebastián ◽

M.E. Gálvez ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Carbon Materials ◽

Synthesis Method ◽

Electrochemical Analysis ◽

Molar Ratio ◽

Synthesis Process ◽

X Ray ◽

Nitrogen Doped ◽

Oxidation Of Methanol ◽

Electro Oxidation

The objective of this work is to study the behavior of Nitrogen-doped carbons as supports of catalysts for the electro-oxidation of methanol. Two carbon materials have been considered: a) carbon xerogels (CXG), highly mesoporous, whose porosity and pore size distribution are easily performed during the synthesis method; b) carbon nanofibers (CNF), which have a high electrical conductivity, good behavior in high temperature conditions and resistance to acid/basic media. Meanwhile, a commercial carbon black (Vulcan XC72R) which is commonly used in manufacturing of electrocatalysts fuel cells was used for comparison. Nitrogen was introduced into the CXG during the synthesis process, what is commonly referred as doping, by including melamine as a reactant. In contrast, N-groups were created over CNF by post-treatment with: ammonia (25%), urea (98%), melamine (99%) and ethylenediamine (99.5%), with a carbon: nitrogen molar ratio 1:0.6. N-containing carbon materials were characterized by elemental analysis, nitrogen adsorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), SEM-EDX and TEM to determinate the amount and forms of nitrogen introduced. Pt-catalysts were prepared by the microemulsion method. The influence of the nitrogen doping and functionalization on the catalytic behavior in the electrochemical oxidation of methanol was evaluated by different physicochemical and electrochemical analysis.

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Construction of Ni-Mo-P heterostructures with efficient hydrogen evolution performance under acidic condition

10.21203/rs.3.rs-324503/v1 ◽

2021 ◽

Author(s):

Tian-Yun Chen ◽

Ya-Qi Zhang ◽

Ying-Yan Fu ◽

Min Qian ◽

Hao-Jiang Dai ◽

...

Keyword(s):

Electron Microscopy ◽

Hydrogen Evolution ◽

Current Density ◽

Photoelectron Spectroscopy ◽

Large Scale ◽

Clean Energy ◽

Hydrogen Energy ◽

Durability Test ◽

X Ray ◽

Onset Potential

Abstract Hydrogen energy is regarded as one of the most important clean energy in the 21st century, and improving the catalytic efficiency of hydrogen evolution reaction (HER) is the basis for realizing the large-scale hydrogen production. Transition metal phosphides (TMPs) were proved to be efficient electrocatalysts for HER. In this work, we first synthesized the nickel-molybdenum bimetallic precursors, followed by high-temperature calcination in air. Finally, NiMoP/MoP nanorods (Ni-Mo-P NRs) was obtained by chemical vapor deposition (CVD) of phosphating. The target catalyst of Ni-Mo-P NRs was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). For Ni-Mo-P NRs, the electrochemical test in 0.5 M H2SO4 solution for HER showed that the optimal feeding ratio was Ni: Mo = 1:1. And the Ni1-Mo1-P NRs presented an onset potential of 63.2 mV, and an overpotential of 117.9 mV was required to drive the current density of 10 mA↔cm− 2. Meanwhile, The Tafel slope, exchange current density (j0), electrochemical double-layer capacitance (Cdl) were 58.6 mV↔dec− 1, 0.10 mA↔cm− 2, 12.6 mF↔cm− 2, respectively. Moreover, there was no obvious activity diminish of Ni1-Mo1-P NRs after a long-term stability and durability test.

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Facile Preparation of Carbon Nitride-ZnO Hybrid Adsorbent for CO2 Capture: The Significant Role of Amine Source to Metal Oxide Ratio

Catalysts ◽

10.3390/catal11101253 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1253

Author(s):

Siti Aishah Anuar ◽

Khairul Naim Ahmad ◽

Ahmed Al-Amiery ◽

Mohd Shahbudin Masdar ◽

Wan Nor Roslam Wan Isahak

Keyword(s):

Electron Microscopy ◽

Metal Oxide ◽

Photoelectron Spectroscopy ◽

Physical Adsorption ◽

Synthesis Method ◽

Chemical Properties ◽

Gaseous Fuel ◽

X Ray ◽

Transmission Electron ◽

Adsorption Analysis

The presence of CO2 in gaseous fuel and feedstock stream of chemical reaction was always considered undesirable. High CO2 content will decrease quality and heating value of gaseous fuel, such as biohydrogen, which needs a practical approach to remove it. Thus, this work aims to introduce the first C3N4-metal oxide hybrid for the CO2 cleaning application from a mixture of CO2-H2 gas. The samples were tested for their chemical and physical properties, using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), physical adsorption analysis (BET), fourier-transform infrared (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The CO2 capacity test was carried out by means of a breakthrough test at 1 atm and 25° C using air as a desorption system. Among the samples, amine/metal oxide mass ratio of 2:1 (CNHP500-2(2-1)) showed the best performance of 26.9 wt. % (6.11 mmol/g), with a stable capacity over 6 consecutive cycles. The hybrid sample also showed 3 times better performance than the raw C3N4. In addition, it was observed that the hydrothermal C3N4 synthesis method demonstrated improved chemical properties and adsorption performance than the conventional dry pyrolysis method. In summary, the performance of hybrid samples depends on the different interactive factors of surface area, pore size and distribution, basicity, concentration of amine precursors, ratio of amines precursors to metal oxide, and framework stability.

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Electrochemical Capacitive Properties of CuO Nanorods Prepared by a Facile Microwave-Assisted Synthesis Method

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.62.21 ◽

2020 ◽

Vol 62 ◽

pp. 21-30

Author(s):

Wei Li ◽

Na Na Feng

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Synthesis Method ◽

Precipitation Method ◽

Microwave Assisted Synthesis ◽

X Ray ◽

Microwave Assisted ◽

Capacitance Performance ◽

Capacitive Properties ◽

Cuo Nanorods

CuO nanorods were fabricated by a facile microwave-assisted synthesis method and applied to pseudo-capacitor. The CuO nanorods were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The capacitive behavior of nanorods was investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. Electrochemical experiments reveal that CuO nanorods demonstrate better capacitance performance than granular CuOs prepared by chemical precipitation method. The CuO nanorods have a high specific capacitance of 317 F/g at a current density of 1 A/g and a fairly good cyclic stability.

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Synthesis of Nitrogen-Doped ZnS with Camellia Brushfield Yellow Nanostructures for Enhanced Photocatalytic Activity under Visible Light Irradiation

International Journal of Photoenergy ◽

10.1155/2013/801846 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Gang-Juan Lee ◽

Chi-Lun Hong ◽

Valentina Batalova ◽

Gennady Mokrousov ◽

Jerry Wu

Keyword(s):

Electron Microscopy ◽

Photocatalytic Activity ◽

Visible Light ◽

Visible Light Irradiation ◽

Photoelectron Spectroscopy ◽

Light Irradiation ◽

X Ray ◽

Nitrogen Doped ◽

Composite Catalysts ◽

N Doping

Nitrogen modified zinc sulfide photocatalysts were successfully prepared and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and surface area analysis. Thermal decomposition of the semisolid was carried out under nitrogen conditions at 500°C for 2 hours, and a series of nitrogen-doped ZnS photocatalysts were produced by controlling inflow flow rate of nitrogen at 15–140 mL/min. Optical characterizations of the synthesized N-doping ZnS substantially show the shifted photoabsorption properties from ultraviolet (UV) region to visible light. The band gaps of nitrogen-doped ZnS composite catalysts were calculated to be in the range of 2.58~2.74 eV from the absorptions edge position. The 15N/ZnS catalyst shows the highest photocatalytic activity, which results in 75.7% degradation of Orange II dye in 5 hrs by visible light irradiation, compared with pristine ZnS and higher percentage N-doping ZnS photocatalysts.

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