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961.
《Calphad》1997,21(3):295-300
The relationship between the interaction parameters of liquid alloys and the atomic parameters of constituent elements has been investigated by artificial neural network method. The relationship found can be used for the computerized prediction of phase diagrams of the eutectic binary systems between non-transition elements. 相似文献
962.
《International Journal of Hydrogen Energy》2020,45(60):35171-35179
The polyvinylidene fluoride (PVDF) drew great attention over time amongst the hydrocarbon polymer membranes because of its high C–F chemical bond strength. In this work is to increase the proton conductivity of the PVDF polymer by doping phosphonated graphene oxide to its structure and investigate the improvement of the membrane. Different amounts of phosphonated graphene oxide additive (0.5%, 1% and 1.5% w/w) were doped to PVDF polymer on the purpose of synthesizing proton exchange composite membranes. Characterization tests, i.e, water uptake, swelling properties, ion exchange capacity, and proton conductivity of the synthesized membranes were investigated. The electrochemical impedance analysis results of synthesized membranes vary between 0.0224 S cm-1 for 0.5% graphene oxide doped PVDF (PVDF/0.5PGO) and 0.0867 S cm-1 for PVDF/1.5GO membrane. The power density values of PVDF/1.5PGO and PVDF/0.5GO are 48 mW cm−2 and 28 mW cm−2 at 0.6 V and 100% relative humidity at 80 °C. The experimental results demonstrate the importance of phosphonated graphene oxide doping into the PVDF composite membrane. 相似文献
963.
《International Journal of Hydrogen Energy》2020,45(27):13841-13847
The catalysts are often used in fuel cells and metal-air batteries to speed up electrochemical reactions. In this study, we prepared CoFe2O4 nanoparticles with mainly inverse spinel structure and FeCo2O4 nanoparticles with mainly spinel structure as bifunctional catalysts by hydrothermal method. After annealing at 350 °C, pure CoFe2O4 and FeCo2O4 nanoparticles with uniform size distribution have been obtained. The CoFe2O4 nanoparticles showed high current density of 5.5 mA/cm2 at −0.8 V in the ORR test. It's low Tafel slope of 83.0 mV/dec further confirmed the excellent ORR catalytic properties of CoFe2O4 nanoparticles. Furthermore, the CoFe2O4 nanoparticles also showed good OER properties with satisfied current density of 35.7 mV/cm2 at l.0 V and low OER Tafel slope of 71.0 mV/dec. Both the ORR and OER properties of CoFe2O4 nanoparticles showed good time stability which were compared with FeCo2O4 nanoparticles. These results indicated that CoFe2O4 nanoparticles with mainly inverse spinel structure had better electrocatalytic performance than FeCo2O4 nanoparticles with mainly spinel structure. The CoFe2O4 nanoparticles with mainly inverse spinel structure show a significant potential application in rechargeable battery. 相似文献
964.
《International Journal of Hydrogen Energy》2020,45(24):13202-13210
Organic-inorganic hybrid nano-material has a significant potential for enhancing the charge separation efficiency of photocatalyst. However, it remains an important issue to controllable synthesis new hybrid system with unique structure and earth-abundant materials for boosting photocatalytic hydrogen revolution. We report a facile one-step hydrothermal strategy to fabricate a novel Titania/β-cyclodextrin (TiO2/β-CD) organic-inorganic hybrid nano-material with an alveolate structure. In this hybrid system, β-CD not only played a critical role in alveolate structure formation, but also served as a bridge connecting target molecular and active sites on the TiO2 surface to facilitate the separation and transfer of the photoexcited electrons with prolonged lifetime. As a result, this alveolate TiO2/β-CD composite exhibited outstanding photocatalytic activity and a H2 evolution rate of 725 μmol/g·h was achieved over TiO2/β-CD which was 14 times of bare TiO2 under simulated sunlight. This work paves a way for controllable synthesis of novel organic-inorganic hybrid nano-material with distinct structure for efficient photocatalysis. 相似文献
965.
《International Journal of Hydrogen Energy》2020,45(24):13290-13299
The exploration of highly efficient non-precious electrocatalysts is essential for water splitting devices. Herein, we synthesized CoS2–MoS2 multi-shelled hollow spheres (MSHSs) as efficient electrocatalysts both for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) using a Schiff base coordination polymer (CP). Co-CP solid spheres were converted to Co3O4 MSHSs by sintering in air. CoS2–MoS2 MSHSs were obtained by a solvothermal reaction of Co3O4 MSHSs and MoS42− anions. CoS2–MoS2 MSHSs have a high specific surface area of 73.5 m2g-1. Due to the synergistic effect between the CoS2 and MoS2, the electrode of CoS2–MoS2 MSHSs shows low overpotential of 109 mV with Tafel slope of 52.0 mV dec−1 for HER, as well as a low overpotential of 288 mV with Tafel slope of 62.1 mV dec−1 for OER at a current density of 10 mA cm−2 in alkaline solution. The corresponding two-electrode system needs a potential of 1.61 V (vs. RHE) to obtain anodic current density of 10 mA cm−2 for OER and maintains excellent stability for 10 h. 相似文献
966.
《International Journal of Hydrogen Energy》2020,45(24):13353-13364
In response to the energy crisis, molybdenum-based catalyst has been proposed as a high-performance electrocatalytic material due to its low price and excellent HER performance. However, in contrast with its excellent HER performance, its poor OER performance often limits practical application as a high-performance overall water splitting catalyst. In this study, Prussian blue analogue (PBA) is grown in-situ on molybdenum-based nanosheet spheres by a simple and ingenious method and then subjected to phosphorization. The resulting composite catalyst exhibits highly efficient overall water splitting performance, overpotentials at current densities of 10 mA cm−2 and 100 mA cm−2 for the HER and OER are −61 mV and 268 mV, respectively. Moreover, an alkaline electrolyzer makes up by the catalyst both as positive and negative can reach a cell voltage 1.494 V at 10 mA cm−2 for the overall water splitting. This method has provided a new strategy to effective combine PBA and molybdenum-based catalyst. 相似文献
967.
《International Journal of Hydrogen Energy》2020,45(30):15317-15326
The nanoparticles of Mn1.5[Cr(CN)6]∙mH2O@Ni1.5[Cr(CN)6]∙nH2O core-shell prussian blue analogues (PBA) embedded with carbon additives (PBA-C) were synthesized and characterized as electrode material for solid state battery application. The impedance spectroscopy and cyclic voltametry were used to study the electrochemical properties by adding functionalized carbon in 1:1 proportion to improve the electrical performance. The value of room temperature electrical conductivity of core-shell PBA and core-shell nanoparticles mixed with vulcan carbon (PBA-C) are found to be 1.574 × 10−3 and 1.92 × 10−3 Scm−1, respectively. Using Li7La3Zr2O12 (LZZO) electrolyte, single cell was fabricated with PBA-C material, and studied its charging-discharging cycles, which exhibits higher current density with stable performance for 400 cycles for time slots of 400 min. The study reveals that the PBA core-shell nanoparticles mixed with carbon (PBA-C) may be a potential candidate as an electrode material in the form of a single cell using LZZO electrolyte. 相似文献
968.
《International Journal of Hydrogen Energy》2020,45(32):15805-15813
The corrosion behavior of pure Mg17Al12 and the effect of ball milling in presence of additives (i.e. graphite (G) and magnesium chloride (MgCl2)) are evaluated in 3.5 wt% NaCl aqueous solution using electrochemical polarization and impedance measurements. Pure Mg17Al12 and milled Mg17Al12 without additives and with MgCl2 present an open current potential (OCP) of −1.2 V/SCE while Mg17Al12 + G shows a slightly higher OCP (+10% maximum). Mg17Al12 corrodes with low kinetics and an increase of corrosion rate for the milled Mg17Al12 is observed. The corrosion current densities (Jcorr) derived from the Tafel plots, exhibit their corrosion reactivity as follow: Mg17Al12 < Mg17Al12 5h < Mg17Al12 + G 5h < Mg17Al12 + MgCl2 5h. Electrochemical impedance spectroscopy (EIS) results are in good agreement with the measured Jcorr. Randles circuit models are established for all samples to explain their surface behavior in the aqueous NaCl solution. The variation of the fitted parameters is attributed either to the effect of ball milling or to the effect of the additive. Our results are helpful in elucidating the effect of ball milling and the additives. 相似文献
969.
《International Journal of Hydrogen Energy》2020,45(32):16071-16079
Pt is the ideal anode catalyst in fuel cells. In this paper, in order to increase the utilization of Pt, the PtAu nanowire networks (NWNs) with ultralow content of Pt are fabricated by a simple silicon monoxide (SiO) reduction method without any capping agent. PtAu NWNs supported on carbon black with Pt content of 1 wt% (Pt0.05Au NWNs) are employed as catalysts for formic acid oxidation (FAO) and methanol oxidation reaction (MOR), whose mass activities are as high as 4998.9 and 2282.3 mA∙mgPt−1, respectively. The network structure facilitates the electron transfer and increases the stability of the catalysts. The PtAu composite experiences compressive lattice strain as confirmed by X-ray powder diffraction (XRD). The Pt0.05Au NWNs catalyst with low Pt content results in the largest strain variation compared with PtAu composited of other ratios, which may downshift the d-band center of Pt and lead to the higher electrocatalytic activity in oxidation reaction. 相似文献
970.
《International Journal of Hydrogen Energy》2020,45(38):19823-19830
To promote the application of traditional (La0.8Sr0.2)0.95MnO3-δ-YSZ (LSM-YSZ) oxygen electrodes to both solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs) modes at intermediate temperatures, we select PdO as the catalyst and ZrO2 as the PdO stabilizer to decorate the LSM-YSZ. The high active PdO particles enhance the electrocatalytic activity, and stable ZrO2 can hinder the growth and agglomeration of the PdO particles. PdO and ZrO2 are co-impregnated into the LSM-YSZ to form a nano-structured PdO/ZrO2 -LSM-YSZ composite electrode. At 750 °C, the obtained cell attains a power density peak of 1.114 W cm−2 in SOFC mode and shows significant improvement of the cell with LSM-YSZ composite oxygen electrode. As a SOEC, when the water content is 90 vol%AH (absolute humidity) at the hydrogen electrode, the cell exhibits an extraordinary current density of 2.322 A cm−2 under applied voltage of 2.0 V at 750 °C. Moreover, the cell shows notable long-term stability during water electrolysis. Therefore, this study demonstrates that the nano-structured PdO/ZrO2 -LSM-YSZ based material as a high active and stable oxygen electrode can greatly promote the application of LSM-YSZ electrode in reversible solid oxide electrolysis cell (RSOCs) field. 相似文献