MATERIALS & DESIGN
·
2016
·
IF 3.997
XinRong Liu,Ming Zhang,TingTing Yang,LiNa Wang,Han Zhu,ShunLi Wang,MingLiang Du
Carbon nanofibers served as nanoreactors for the design and construction of PtCo alloy carbon core-shell nanostructures with nitrogen doping (PtCo/NCNF) through a combination of electrospinning and nitrogen doping treatments. The PtCo/NCNF hybrid consists of PtCo alloy nanoparticles surrounded by a few of N-doped carbon layers , demonstrating a typical core-shell structures. The PtCo/NCNF hybrid can both served as electrode materials for electrocatalytic water splitting including hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). For the HER performance, the PtCo/NCNF exhibits very small onset potential of 20 mV, an overpotential of 50 mV at a j (vs RHE) = 10 mA cm − 2 and Tafel slope of 30 mV dec − 1 . The PtCo/NCNF hybrid also exhibits high OER activity with an onset potential of 310 mV, an overpotential of 400 mV at a j of 10 mA cm − 2 and a small Tafel slope of 76 mV dec − 1 . The high catalytic activities of PtCo alloy for HER and OER originate from the 3D hierarchical structures, well-dispersed PtCo alloy, high conductivity of NCNF, protection from the carbon-encapsulated structure, and the introduction of nitrogen.
研究领域:
材料科学
·
纳米技术
·
电化学
·
能源化学
·
催化化学
·
功能材料
✓ 已验证
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2024
·
IF 4.8
Shuai Ma,Di Dong,Mengyao Zhang,Ye Gao,Zhuangzhi Wu,Dezhi Wang
W-Re-HfC alloys have been extensively applied in the field of high-temperature structural parts. To ensure high temperature reliability, it is essential to enhance creep resistance ability. In this study, the microstructures of forged W-Re-HfC alloys were adjusted using different heat treatment processes . The corresponding tensile creep properties were also measured at 2000 °C with 40 MPa. Furthermore, a possible creep fracture mechanism was also explored. The forged W-Re-HfC sample annealed for 2 h exhibited the best creep performances with a steady-state creep rate of 3.28 × 10 −6 and a creep life of 5.6 h. Generally, a larger grain size indicates a lower steady-state creep rate; however, the precipitation of carbides at the grain boundaries (GBs) deteriorates the bonding strength of interfaces, thus reversing the former trend. The dominant creep mechanism is diffusion creep , in which the voids nucleate perpendicular to the GBs, grow and connect into cracks, ultimately leading to fractures.
研究领域:
材料科学
·
金属学与热处理
·
高温结构材料
·
固态物理
·
力学性能
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2022
·
IF 3.699
Tayfun Kocak,Xiadong Qi,Xiaogang Zhang
The extended cyclability of LiNi 0.5 Mn 1.5 O 4 (LNMO) electrodes featuring different water-based binders is here reported. LNMO electrodes with guar gum (GG) binders show a relatively stable cycle performance at 0 °C and room temperature. However, water-based binders exhibit higher capacity fade than those with polyvinylidene fluoride (PVdF) binder at 50 °C. Although PVdF binder has a lower adhesion force than CMC and GG; PVdF-based electrodes exhibit better capacity retention than those with water-based binders at 50 °C over 1000 cycles. Finally, operando Differential Electrochemical Mass Spectrometry (DEMS) experiments were carried out to analyze the evolution of volatile decomposition products formed over cycling at 1C and 30 °C of CMC-, GG- and PVdF-based LNMO electrodes. CO 2 and H 2 gas evolutions increase remarkably at both high temperatures and high potentials, i.e., ~ 4.7 V.
研究领域:
电化学
·
材料科学
·
能源存储
·
锂离子电池
·
电极材料
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2018
·Vol. 2018
·期 1
·1634814
·
IF 2.207
Lianbing Zhong,Guihong Geng,Yujin Wang,Feng Ye,Limeng Liu
A fully dense TaC ceramic was prepared by hot pressing using 10 mol% ZrC plus 5 mol% Cu as a sintering aid. Formation of (Ta, Zr)C solid solution (ss) by reaction between TaC and ZrC facilitated densification. Addition of Cu refined the microstructure and consequently improved flexural strength of the TaC ceramics. TEM investigation found ubiquitous precipitation of nanocrystallites at multigrain conjunctions. The nanocrystallites were (Ta, Zr)C solid solution with uniform dispersion in an oxygen-rich glassy matrix. Although formation of nanoprecipitates may not much affect the mechanical properties of the TaC ceramic, the structure suggested a new type of nanoceramic worth further research.
研究领域:
材料科学
·
陶瓷学
·
固态化学
·
显微结构分析
·
复合材料
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Jinxing Yu,Lei Zhang,Jun Qian,Zhirong Zhu,Shuang Ni,Gang Liu,Xiaoxiang Xu
Starting from two wide band gap semiconductors AgTaO 3 and SrTiO 3 , we managed to reduce the band gap by forming their solid solutions, i.e. (AgTaO 3 ) 1-x (SrTiO 3 ) x (0.0 ≤ x ≤ 1.0). These solid solutions all adopt cubic perovskite structure similar to SrTiO 3 and high temperature phase of AgTaO 3 , suggesting that SrTiO 3 is helpful to stabilize AgTaO 3 in its high temperature cubic phase. Substantial improvements over photocatalytic hydrogen production were realized in these solid solutions which clearly outperform their parent compounds AgTaO 3 and SrTiO 3 . In-situ exolution of silver nanoparticles at the surface of solid solutions (x = 0.2) substantially strengthen the visible light absorption due to localized surface plasmons of these silver nanoparticles . This contributes to further improvements on both photocatalytic hydrogen and oxygen production under visible light illumination (λ ≥ 400 nm). Apparent quantum efficiency as high as ˜ 2.02% and ˜ 0.11% was achieved at solid solutions (x = 0.2) decorated with silver nanoparticles for full range (λ ≥ 250 nm) and visible light (λ ≥ 400 nm) illumination respectively. Photoelectrochemical analysis suggests that solid solutions own a better charge separation conditions than their parent compounds. Furthermore, the band edge positions of solid solutions (x = 0.2) lie approximately in the middle between AgTaO 3 and SrTiO 3 , being ideal for solar water splitting reactions.
研究领域:
材料科学
·
光催化
·
能源化学
·
半导体物理
·
纳米材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2013
·Vol. 38
·期 13
·5251-5258
·
IF 3.548
Qiang Zhao,Zhuobin Yu,Wen Yuan,Jinping Li
Under mild conditions (near-neutral aqueous solutions, room temperature , and atmospheric pressure), an attractive electrolyte was expanded for splitting water and three novel oxygen-evolution catalysts (Co-C i , Ni-C i , Ag-C i ) were generated. The Co-C i catalyst showed a high oxygen-evolution rate (24.42 μmol h −1 ), a low oxygen-evolution overpotential (395 mV) and excellent stability. In addition, the non-amorphous Ag-C i catalyst, different from reported catalyst, was generated. The catalyst has been further characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS).
研究领域:
材料化学
·
电化学
·
催化化学
·
能源科学
·
纳米材料
✓ 已验证
DOI
高影响因子
Small
·
2023
·Vol. 19
·期 41
·2302685
·
IF 13.3
Hancheng Ma,Xiang Huang,Luyu Li,Wei Peng,Sheng Lin,Yao Ding,Liqiang Mai
PtTe 2 , a member of the noble metal dichalcogenides (NMDs), has aroused great interest in exploring its behavior in the hydrogen evolution reaction (HER) due to the unique type-II topological semimetallic nature. In this work, a simple template-free hydrothermal method to obtain the phosphorus-doped (P-doped) PtTe 2 nanocages with abundant amorphous and crystalline interface (A/C-P-PtTe 2 ) is developed. Revealed by density functional theory calculations, the atomic Te vacancies can spontaneously form on the basal planes of PtTe 2 by the P doping, which results in the unsaturated Pt atoms exposed as the active sites in the amorphous layer for HER. Owing to the defective structure, the A/C-P-PtTe 2 catalysts have the fast Tafel step determined kinetics in HER, which contributes to an ultralow overpotential ( η = 28 mV at 10 mA cm −2 ) and a small Tafel slope of 37 mV dec −1 . More importantly, benefiting from the inner stable crystalline P-PtTe 2 nanosheets, limited decay of the performance is observed after chronopotentiometry test. This work reveals the important role of the inherent relationship between structure and activity in PtTe 2 for HER, which may bring another enlightenment for the design of efficient catalysts based on NMDs in the near future.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
计算材料学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 20
·7296-7301
·
IF 5.101
Jungang Hou,Rui Cao,Zheng Wang,Shuqiang Jiao,Hongmin Zhu
Single-crystalline chromium doped bismuth titanate (Bi4Ti3−xCrxO12, x = 0.0–0.5) nanosheets with exposed {110} facets have been synthesized via a facile hydrothermal process. The Bi4Ti3−xCrxO12nanosheets possess well-defined tetragonal shapes with landscape dimension of 100–300 nm and thickness of 10–30 nm. The in-plane surfaces of the nanosheets lies on {001}, and the side surfaces are (110) and (10). Extension of the light absorption from the ultraviolet region to the visible-light region arises from the Cr 2p levels confirmed by XPS spectra. The Bi4Ti2.6Cr0.4O12 nanosheets with high stability showed the highest photocatalytic performance of H2 evolution from water under visible-light irradiation. Furthermore, the heterostructures by using the NiOx nanoparticles tightly coupled on the surface of Bi4Ti2.6Cr0.4O12 nanosheets, exhibited an enhanced photocatalytic activity due to the decrease in the recombination rate of the photoinduced electrons and holes, demonstrating that NiOx/Bi4Ti2.6Cr0.4O12 nanosheet is a promising candidate as a visible light photocatalyst.
研究领域:
材料科学
·
光催化
·
纳米材料
·
能源化学
·
半导体物理
·
表面科学
·
无机化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2021
·Vol. 42
·期 10
·1798-1807
·
IF 8.271
Xiangyong Zhang,Tianying Liu,Ting Guo,Xueying Han,Zongyun Mu,Qiang Chen,Jiangmin Jiang,Jing Yan,Jiaren Yuan,Dezhi Wang,Zhuangzhi Wu,Zongkui Kou
Controllably mounting foreign atoms on the surfaces of earth-abundant electrocatalysts strongly improve their surface electronic properties for optimizing the catalytic performance of surficial sites to an unusual level, and provides a good platform to gain deep insights into catalytic reactions . The present work describes, employing ultrafine W 2 C nanoislands (average size: 2.3 nm) monodispersed on the N, P dual-doped carbon frameworks as a model system, how to regulate the atomic phosphorous-mounting effect on the surfaces of W 2 C to derive an active and stable P-mounting W 2 C (WCP) catalyst for both acidic and alkaline hydrogen evolution reaction (HER). Since in situ phosphorus substitution into carbon sites of preformed W 2 C nanoislands gradually proceeds from surfaces to solids, so that using a proper amount of phosphorus sources can readily control the surface mounting level to avoid the mass P-doping into the bulk. By this way, the activity per active site of WCP catalyst with robust stability can be optimized to 0.07 and 0.56 H 2 s −1 at –200 mV overpotential in acid and base, respectively, which reach up to the several-fold of pure-phase W 2 C (0.01 and 0.05 H 2 s −1 ). Theoretical investigations suggest that compared with solid P doping, the P mounting on W 2 C surface can more remarkably enhance its metallicity and decrease the hydrogen release barrier. This finding disclosed a key correlation between surface foreign atom-mounting and catalytic activity , and suggested a logical extension to other earth-abundant catalysts for various catalytic reactions .
研究领域:
材料化学
·
电催化
·
纳米材料
·
能源科学
·
表面科学
·
理论计算
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Xiaozhen Chen,Ji Qi,Pan Wang,Chuang Li,Xiao Chen,Changhai Liang
Herein, PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness are synthesized via a polyvinyl alcohol (PVA) involved approach and used for hydrogen evolution reaction (HER). The average crystallite size of the PVA protected nMo 2 CN nanospheres (6.1 nm) is one third of that of the PVA-Mo 2 C/Mo 2 N without PVA protection (17.9 nm). At 10 mA cm −2 current density, the as-synthesized PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness exhibit HER overpotentials of 132 mV and 142 mV with corresponding Tafel slope of 51.8 mV dec −1 and 50.4 mV dec −1 in acid and alkaline medium, respectively. This high apparent activity can be attributed to the high intrinsic activity originated from the adjacent surface active sites of Mo 2 C and Mo 2 N as well as the large ECSA of PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源化学
·
表面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Hui Wang,Houzhen Chen,Hongjiao Wang,Lei Wu,Qixing Wu,Zhongkuan Luo,Fang Wang
The electrochemical performance of the lithium−oxygen (Li−O 2 ) batteries largely depends on the material and architecture of the catalytic cathode. In this paper, to avoid the parasitic reactions of carbon and binder with discharge products and reaction intermediates, we proposed an effective design of a free-standing catalytic cathode for Li−O 2 batteries. The FeCo 2 O 4 @Ni electrode consists of FeCo 2 O 4 nanosheets grown directly on nickel (Ni) foam. The resultant hierarchical macroporous/mesoporous structure provides sufficient space for the insoluble discharge product Li 2 O 2 and catalytically active sites for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Consequently, the carbon- and binder-free self-supporting electrode has demonstrated a high discharge capacity with relatively low charge overvoltage and a better cycle performance than the corresponding carbon-based electrodes.
研究领域:
电化学
·
能源材料
·
纳米材料
·
电催化
·
储能技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Qingyan Zhou,Zhen Zhang,Jiajun Cai,Bing Liu,Yunlong Zhang,Xiaofei Gong,Xulei Sui,Aiping Yu,Lei Zhao,Zhenbo Wang,Zhongwei Chen
Rational design and construction of highly efficient and durable non-noble-metal bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial to promote the widespread implementation of rechargeable Zn-air batteries. Herein, a bifunctional catalyst comprising Co nanoparticles uniformly embedded in hollow nitrogen doped carbon tubes (Co@hNCTs) is fabricated by a facile tube-directed templating strategy. In this strategy, surfactant-treated polypyrrole (PPy) nanotubes serve as the structure-guiding templates for efficient capture of Co 2+ , realizing the in-situ growth of zeolitic imidazolate frameworks-67 (ZIF-67) nanocrystals on PPy nanotubes . Sodium laurylsulfonate acts as anionic surfactant to endow PPy nanotubes with functional electronegative surface and strong anchoring effect toward ZIF-67, playing the pivotal role in binding of ZIF-67 nanocrystals with PPy nanotubes potently. Consequently, the developed catalyst presents a superior ORR activity with the half-wave potential of 0.87 V excellent durability with only a 7 mV loss of half-wave potential after 5000 cycles. The catalyst also exhibits superior catalytic performance for OER. When serving as an air electrode in Zn-air batteries, a large power density of 149 mW cm −2 and long-term cyclability for over 500 h are realized in ambient air, implying the great potential in practical application.
研究领域:
材料科学
·
电化学
·
能源存储
·
催化化学
·
纳米材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）