Surface Topography-Metrology and Properties
·
2020
·Vol. 8
·期 3
·035014
·
IF 1.613
Weiwei Zhang,Cuicui Ji,Qiang Fu,Zhongquan Shi
In this work, the structure and properties of ZrO2 nanoparticle reinforced Ni–W, Ni–B and Ni–Cu matrix nanocomposite coatings were comparatively studied. Their surface morphology, composition, microstructure, topography, hardness, wear and corrosion resistance were examined by various methods . The nanocomposites exhibit dense, nodular-like morphology with nanocrystalline structure. The results show that the ZrO2 particles have homogeneously dispersed in the nanocomposites. The formation of the protrusion structure was partly attributed to the heterogeneous distribution of the electric field. The presence of ZrO2 nanoparticles could refine the crystallite size of the Ni–W, Ni–B and Ni–Cu alloy matrix to 12.5 ± 1, 10.5 ± 0.5 and 15 ± 0.1 nm, respectively. The corrosion resistance of these nanocomposites can be improved by the incorporation of ZrO2 nanoparticles into the alloy matrix. The Ra of Ni–W/ZrO2, Ni–B/ZrO2 and Ni–Cu/ZrO2 nanocomposites are about 53 ± 3, 69 ± 2, 18 ± 1 nm, respectively, expressing the rougher surface of Ni–B/ZrO2 compared to the others. It indicated that the composition of these alloy matrix have different crystallite size, which could affect the surface roughness of the electrodeposits. The inclusion of ZrO2 particles in Ni-based alloys could enhance its properties. The reinforcement effect of the anti-wear properties of the nanocomposites was proposed. The Rct value of the Ni–W–ZrO2, Ni–B–ZrO2, Ni–Cu–ZrO2 were 50.93, 105.18, 44.67 kΩ · cm2, respectively, indicating that the Ni–B–ZrO2 nanocomposite coating has the highest corrosion resistance. The Rct values depends on not only the composition of the coatings, but also the electrodeposition conditions, which influence the crystallize size and compactness of the electrodeposits. The order of the microhardness and anti-wear properties is Ni–W–ZrO2 > Ni–B–ZrO2 > Ni–Cu–ZrO2.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
Materials
·
2016
·Vol. 9
·期 10
·795
·
IF 2.728
Jinzhu Tang,Qi Ding,Songwei Zhang,Guizhi Wu,Litian Hu
Nanomaterials, such as Graphene, h-BN nanoparticles and MoS2nanotubes, have shown their ability in improving the tribological performance of amorphous carbon (a-C) coatings. In the current study, the effectiveness of ZrO2nanoparticles (ZrO2-NPs) in lubricating the self-mated nonhydrogenated a-C contacts was investigated in boundary lubrication regime. The results showed that 13% less friction and 50% less wear compared to the base oil were achieved by employing ZrO2-NPs in the base oil in self-mated a-C contacts. Via analyzing the ZrO2-NPs and the worn a-C surface after tests, it was found that the improved lubrication by ZrO2-NPs was based on “polishing effects”, which is a new phenomenon observed between a-C and nanoparticles. Under the “polishing effect”, micro-plateaus with extremely smooth surface and uniform height were produced on the analyzed a-C surface. The resulting topography of the a-C coating is suitable for ZrO2-NPs to act as nano-bearings between rubbing surfaces. Especially, the ZrO2-NPs exhibited excellent mechanical and chemical stability, even under the severe service condition, suggesting that the combination of nonhydrogenated a-C coating with ZrO2-NPs is an effective, long lasting and environment-friendly lubrication solution.Keywords:amorphous carbon coating;ZrO2nanoparticles;friction coefficient;wear;polishing effect
研究领域:
材料科学
·
摩擦学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2023
·
IF 5.4
Lin Ge,Dong-Mei Huang,Qin-Chao Xu,Jing Shi,Shuai Chen
An innovative, high-performance, non-noble-metal-based oxygen reduction reaction (ORR) catalyst must be developed utilizing a new and cost-effective technique. ZrO 2 has the merits of high stability, low toxicity, good catalytic activity, and low enthalpy for atomic oxygen adsorption. However, the poor conductivity restricts its application as an ORR catalyst. Here, we successfully prepared ZrO 2 nanoparticles / nitrogen-rich two-dimensional carbon nanosheet composites as ORR catalysts using a straightforward, solvent-free, one-step pyrolysis approach. Due to the unique component and structure characteristics, ZrO 2 @N-C-900 demonstrates remarkable ORR performances in alkaline electrolytes, such as high half-wave potential (0.82 V vs. RHE), higher current density (J L = 6.4 mA cm −2 ), and outstanding long term stability (95 % for 36,000 s). Especially, when used in a Zn-air battery, ZrO 2 @N-C-900 exhibited a power density of 148 mW cm −2 , exceeding that of 20 % Pt/C.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 4
·668
·
IF 5.719
Qingyun Li,Lingyu Liu,Zihua Wang,Xuezhong Wang
A confined jet mixing reactor operated in continuous hydrothermal flow synthesis was investigated for the synthesis of CeO2-ZrO2(CZ) nanoparticles. The obtained ultrafine powders were characterized using scanning electron microscopy–energy dispersive spectrometry (SEM-EDS), inductively coupled plasma–atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED), a BET (Brunauer-Emmett-Teller)-specific surface area test and pore analysis, oxygen storage capacity (OSC) test, and a H2temperature programmed reduction (H2-TPR) test. The XRD results show that all samples were composed of high-purity cubic CZ nanoparticles. High resolution transmission electron microscope (HR-TEM) analysis showed that CZ nanoparticles with uniform size and shape distributions were obtained in this investigation. The d-spacing values, determined based on the TEM-selected area electron diffraction (SAED) patterns, were in good agreements with the reference data. BET results showed that the prepared CZ samples had large specific surface areas. Pore volume and size distribution were obtained by pore analysis. Oxygen pulse adsorption technology was used to test the oxygen storage capacity of the sample. The redox capacity of the CZ material was determined by a H2temperature-programmed reduction test.Keywords:continuous hydrothermal flow synthesis;confined jet mixing reactor;CeO2-ZrO2nanoparticles;XRD;BET
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 52
·期 3
·609-620
·
IF 4.569
Samuel Guemou,Dongqiang Gao,Fuying Wu,Jiaguang Zheng,Tao Wei,Zhendong Yao,Danhong Shang,Liuting Zhang
As an ideal material for solid-state hydrogen storage, magnesium hydride (MgH2) has attracted enormous attention due to its cost-effectiveness, abundant resources, and outstanding reversibility. However, the high thermodynamics and poor kinetics of MgH2 still hinder its practical application. In this work, a simple stirring–hydrothermal method was used to successfully prepare bimetallic Mn3O4/ZrO2 nanoparticles, which were subsequently doped into MgH2 by mechanical ball milling to improve its hydrogen sorption performance. The MgH2 + 10 wt% Mn3O4/ZrO2 composite began discharging hydrogen at 219 °C, which was 111 °C lower compared to the as-synthesized MgH2. At 250 °C, the MgH2 + 10 wt% Mn3O4/ZrO2 composite released 6.4 wt% hydrogen within 10 min, whereas the as-synthesized MgH2 reluctantly released 1.4 wt% hydrogen even at 335 °C. Moreover, the dehydrogenated MgH2 + 10 wt% Mn3O4/ZrO2 sample started to charge hydrogen at room temperature. 6.0 wt% hydrogen was absorbed when heated to 250 °C under 3 MPa H2 pressure, and 4.1 wt% hydrogen was taken up within 30 min at 100 °C at the same hydrogen pressure. In addition, compared with the as-synthesized MgH2, the de/rehydrogenation activation energy values of the MgH2 + 10 wt% Mn3O4/ZrO2 composite were decreased to 64.52 ± 13.14 kJ mol−1 and 16.79 ± 4.57 kJ mol−1, respectively, which incredibly contributed to the enhanced hydrogen de/absorption properties of MgH2.
研究领域:
材料科学
·
氢能
·
纳米技术
✓ 已验证
DOI
高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2019
·Vol. 103
·期 1
·199-205
·
IF 1.65
Zhang Wanying,Huang Yingnan,Gong Hua,Dang Fei,Zhou Dongmei
Metal dioxide nanoparticles (NPs) are produced in ever-increasing amounts and widely used in industrial, medical and consumer products. They may pose potential risks to the environment. In this study we quantitatively evaluated the phytoavailability of CeO 2 NPs, ZrO 2 NPs and SiO 2 NPs to wheat ( Triticum aestivum L.). Metal dioxide NPs showed distinct differences in uptake, with uptake rate constants of 90.2 ± 9.9, 12.2 ± 2.5, 0.4 ± 0.02 and 0.9 ± 0.1 L kg −1 h −1 for ZrO 2 NPs, CeO 2 NPs, SiO 2 NPs (13 nm) and SiO 2 NPs (25 nm), respectively. However, such difference cannot be generalized by single factor of NP characteristics and/or root damage. This study provides fundamental information for NP uptake by crop plants.
研究领域:
环境科学
·
植物学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 30
·21799-21807
·
IF 3.9
Yijin Sheng,Fangxu Hu,Yu Wu,De Li,Wenting Ji,Yong Chen
The electrochemical oscillation in Li-ion batteries has been reported for two-phase electrode materials of Li4Ti5O12 and LiCrTiO4, which is originated from the group-by-group phase transition in a multi-particle electrode. For both Li4Ti5O12 and LiCrTiO4, the electrochemical oscillation exhibits usually during charging, while rarely for discharging. Herein, a series of Zr-modified Li4Ti5O12 samples are prepared by using the spray-drying combined with high-temperature sintering method, and the electrochemical oscillation is observed during not only the charging process, but also the discharging process, which gradually grows up and then disappears by increasing the Li content. Compared with Li4Ti5O12, the specific capacity of Zr-modified Li4Ti5O12 decreases gradually by increasing the Zr/Ti ratio, owing to the impurity phases. According to the XRD, XPS and STEM results, the Zr element tends to accumulate on the surface to form ZrO2 nanoparticles, rather than dope into the bulk phase of Li4Ti5O12, which makes Li4Ti5O12 particles well dispersive. In contrast to the Li deficiency for only charging, the electrochemical oscillation during both charging and discharging should be attributed to the Li excess, but too much Li2TiO3 phase will suppress the electrochemical oscillation. Therefore, the Li excess can induce the electrochemical oscillation during both charging and discharging of Zr-modified Li4Ti5O12, which can be adopted to investigate the electrochemical oscillation of other materials in LIBs.
研究领域:
材料科学
·
电化学
·
电池技术
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）