Ultrafine Pt nanocrystals with an average particle size of 2.2 ± 1 nm coupled over the petaloid Fe
P surface are proposed as a novel, efficient, and robust catalyst for alcohol fuel ...electro-oxidation. The strong coupling effect of metal-support imparts a strong electronic interaction between the Fe
P and Pt interface that can weaken the adsorption of poisoning CO species according to the d-band theory. Defects and increased surface area of the petaloid Fe
P are beneficial to the Pt nanoparticle anchoring and dispersion as well as the charge transfer and reactant transportation during the electrochemical reaction. These features make the Pt-Fe
P catalyst system exhibit excellent catalytic activity, antipoisoning ability, and catalytic stability for alcohol fuel of methanol and ethanol electro-oxidation compared with a controlled Pt/C catalyst. The high catalytic efficiency is proposed to come from the strong coupling effect of Pt and petaloid Fe
P interface that can maintain the mechanical and chemical stability of the catalyst system. This kind of phosphide-supported ultrafine Pt nanocrystals will be a promising catalyst in fuel cells.
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To solve environmental pollution and energy crisis, it is essential to design an efficient, economical, and stable bifunctional electrocatalyst for water splitting to produce ...renewable energy sources H2 and O2. In this study, low-crystallinity and microspherical CoFe-P/NF catalyst synthesized by potentiostat electrodeposition on a foam nickel substrate had an excellent hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and water splitting performance. In 1 M KOH solution, the CoFe-P/NF required the overpotentials of 45 mV for HER and 287 mV for OER in order to create a current density of 10 mA cm−2. Furthermore, the Tafel slope for HER and OER was measured as 35.4 and 43.2 mV dec-1, respectively. Serving as the bifunctional catalysts, the CoFe-P/NF electrode couple displays a low voltage of only 1.58 V at 10 mA cm−2 with an excellent long-term stability. Such remarkably properties of the CoFe-P/NF are attributed to the crystalline-amorphous phase structure, the synergistic effect of Co, Fe and P, and rapid separation of bubbles from the electrode surface. In summary, this study provides a new method for developing cost-effective catalyst towards green hydrogen production via water splitting.
Transition-metal phosphides have a potential application in lithium-ion batteries (LIBs) because of their high theoretical capacities and low cost; nevertheless, they possess dramatic volumetric ...variation during cycling associated with poor conductivity, limiting their practical applications. Here, a three-dimensional (3D) hierarchical flowerlike FeP coated with nitrogen-doped carbon layer (FeP@N,C hybrid) was constructed through a solvothermal method, followed by a phosphating approach under low temperature. N-doped carbon not only suppresses the volume fluctuation of FeP, but also promotes electron transfer, accompanied by catalyzing the decomposition of Li3P to improve the reversibility of the FeP@N,C hybrid during cycling processes. In addition, a 3D flowerlike architecture assembled from porous nanosheets is also beneficial for shortening the migration path of ions as well as improving the contact area of electrode with electrolyte, which enhances the reaction kinetics and is proved by both experimental measurement of Li+ diffusion coefficient and resistivity, along with the calculation of density functional theory. Consequently, the 3D hierarchical flowerlike FeP@N,C hybrid performs excellent cyclic stability (569 mA h g–1 at a current density of 500 mA g–1 for the 300th cycle) and rate performance (331.94 mA h g–1 at a high current density of 5 A g–1) for LIBs. Based on above results, the fabrication strategy in this work could offer a thought to design other high-performance metal phosphide hybrids.
The photocatalyst is a crucial factor in determining solar-to-H2 efficiency for solar-driven water splitting. Here, the FeP/CdS well-defined heterostructure was elaborately designed and successfully ...constructed in-situ to achieve efficient water splitting by using a simple and green solvothermal approach. In the synthetic process, the ethylenediamine plays an important role in the construction of intimate contact interface between FeP and CdS. This good quality FeP/CdS heterostructure can efficiently promote charge separation and transportation, and therefore the charge recombination of CdS was significantly suppressed. As a result, the as-synthesized FeP/CdS heterostructure showed excellent photocatalytic performance under visible-light irradiation with an optimal hydrogen evolution rate of 37.92 mmol g−1 h−1 and an apparent quantum yield of 31.50% at 420 nm far exceeding that of pristine CdS by more than 122 folds. This rate, to the best of our knowledge, outperforms other similar catalytic systems.
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•Well-defined FeP/CdS heterostructure was fabricated with the assistance of amine.•Construction and catalytic mechanism of FeP/CdS was detailedly studied.•Intimate contact interface contributes to its good performance.
•FeP with phosphorus vacancies has been firstly designed for LIBs.•Porous FeP nanorods were synthesized from simple self-template method.•The V-FeP exhibited capacity of 590.7 mAh g−1 after 1000 ...cycles at 2.0 A g−1.
With high theoretical capacity (926 mAh g−1) and safer voltage platform, Iron phosphide (FeP) as an anode material for lithium ion batteries has attracted a lot of attention. However, FeP also suffers serious capacity fading and unsatisfied rate capability, which are triggered by inferior intrinsic conductivity and large volume expansion. Herein, oriented by density functional theory (DFT) calculations, MOF-derived porous FeP nanorods modified by abundant P vacancies (denoted as V-FeP) were ingeniously designed via a simplified approach to alleviate the above obstacles. As a result, the V-FeP nanorods electrode delivered extraordinary specific capacity (1228.3 mAh g−1 at 0.1 A g−1 after 120 cycles) and long-cyclic performance (590.7 mAh g−1 at 2.0 A g−1 after 1000 cycles). Transmission electron microscopy, X-ray absorption fine structure, electron paramagnetic resonance and so on were used to character the V-FeP nanorods. The results indicated the supernormal electrochemical performances of V-FeP nanorods were originated from abundant P vacancies and good distribution of FeP nanoparticles in conductive carbon network, which enhanced electrical conductivity, provided more active sites, shortened the diffusion distances of Li ions and relieved the volume variations. The strategy demonstrates a further direction to effectively improve the lithium storage performance of transition metal phosphides.
Iron phosphide (FeP) has been recently demonstrated as a very attractive electrocatalyst for the hydrogen evolution reaction (HER). However, the understanding of its properties is far from ...satisfactory. Herein, we report the HER performance of FeP nanoparticles is enhanced after a stability test due to reduced surface-charge-transfer resistance in the HER process. The synthetic temperature and reactant ratio are important for surface-charge-transfer resistance, the electrochemically active surface area, and HER activity. Hydrogenation apparently improves the HER performance of FeP nanoparticles by reducing the surface-charge-transfer resistance, overpotential, and Tafel slope. Enhanced HER performance is observed after a stability test for both bare and hydrogenated FeP nanoparticles in the HER due to reduced surface-charge-transfer resistance. Thus, this study may enrich our knowledge and understanding to advance HER catalysis for electrochemical hydrogen generation.
Petaloid FeP powder is an efficient and robust catalyst for electrochemical hydrogen evolution reaction (HER) both in the acid and alkaline electrolyte. The whiskers and defects in the petaloid ...structure can extend the surface area and avoid particles aggregation, thus high electrochemical activity and mechanical structure stability are guaranteed for the HER. Specifically, it needs an overpotential of 110 mV and 185 mV at 10 mA cm−2 in acid solution and alkaline solution respectively. This powder FeP catalyst is promising in PEM water electrolysis.
Petaloid FeP powder catalyst is robust and efficient for HER both in acid and alkaline solution. The performance outperforms most of the supported Fe-P catalyst indicating the promising applications in PEM water electrolysis. Display omitted
•Petaloid FeP powder is efficient for electrochemical hydrogen evolution reaction•High electrochemical activity and mechanical structure stability for the HER•Petaloid structure can extend the surface area and avoid particles aggregation.•The performance of powder FeP outperforms most of the supported Fe-P catalyst.
A rational designed porous FeP nanoflake modified with metallic Fe nanoparticles for efficient hydrogen evolution in neutral electrolyte.
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•Fe NPs modified FeP nanoflakes as an ...excellent HER catalyst in neutral electrolyte.•The presence of Fe improves the electronic conductivity and catalytic activity of FeP.•Hierarchical catalyst architecture promotes ions diffusion into inner active sites.•High catalytic rate of 250 A cm−2 g−1 is achieved at overpotential of 295 mV.
Metal phosphides are promising electrocatalysts for hydrogen evolution reaction (HER). However, their applications are hindered by the low electronic conductivity and sluggish HER kinetics in neutral electrolytes. Here we report an approach to significantly improving the HER performance of hierarchical iron phosphide (pFeP) modified with metallic iron (Fe) in neutral phosphate buffer electrolytes. It was observed that the presence of Fe can accelerate the charge transport kinetics. As a result, a significant improvement on the proton-acceptor (negatively charged P sites) and hydride-acceptor (coordinated Fe sites) were achieved, therefore promoting proton adsorption to the electrocatalyst surface during water electrolysis. Specifically, the Fe modified FeP electrocatalyst (pFe/FeP) displayed high HER catalytic rates (e.g., −100 mA cm−2 at an overpotential of −380 mV), low onset potential (50 mV), and excellent long-term stability for 40 h in neutral electrolyte. This study provides a new approach to the design and synthesis of noble-metal-free electrocatalysts with excellent performance for hydrogen production in neutral electrolytes.
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•Tailored core–shell phosphide@carbon nanowires were synthesized.•There are strong chemical bond interactions between the core–shell Fe2P@C.•Fe2P@C nanowires on the foam were used ...directly as an all-in-one anode.•The cell showed a high surface capacity at a large current density.
Metal phosphides are superior anode materials for secondary batteries but suffer from variable volume and low electronic conductivity. In this work, chemically bonded metal phosphide@carbon nanowire arrays with adjustable structure mounted on foam metal were synthesized via a general facile chemical vapor deposition (CVD)-like approach using an environmentally friendly, solid ionic resin as a phosphorus source. The diameter of the nanowires and thicknesses of the carbon shell could be tailored via control of the synthesis conditions. Using a Fe2P@C array on iron foam as an example, it was demonstrated that the new materials could be used directly as an electrode in sodium-ion batteries (SIBs) without any additives or post-processing. The Fe2P@C electrode delivered a significantly high area capacity of 0.40 mAh cm−2 after 1400 cycles at a current density of 3 mA cm−2, a capacity retention rate of 80.25 %, which is, to the best of our knowledge, one of the most stable, high surface capacity performances achieved in SIBs at this large current density. Tests showed that the Fe2P@C nanowire array on a 3D foam structure provided a larger exposure area for electrolyte penetration, a shorter passage for Na+ diffusion, and faster electronic transfer. In situ TEM revealed that the carbon shell effectively alleviated volume expansion of the Fe2P and in-situ Raman and XRD verified the mechanism and high reversibility of Fe2P@C.
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•The FexP/PMS system was firstly presented for elimination of sulfonamides and exhibited favorable catalytic activity.•The FexP particles presented a unique spherical coralloid ...morphology structure.•The magnetically separable catalyst exhibited favorable reusability.•OH, SO4−, 1O2 and O2− contributed to the elimination of sulfonamides.
Transition metal phosphides (TMPs) have emerged as a promising catalyst in the environmental catalysis field due to the excellent catalytic property, high conductivity and long stability. Herein, spherical-coral-like iron phosphide (FexP) particles contained FeP orthorhombic crystals and Fe2P hexagonal crystals were innovatively constructed by a facile low-temperature phosphating synthesis strategy. This novel heterogeneous catalyst with unique morphology was firstly employed for peroxymonosulfate (PMS) activation to eliminate SDZ. It was turned out that FexP possessed favorable catalytic activity for activating PMS and could eliminate SDZ up to 98.2% within 24 min. Compared with Fe2O3 without further phosphatizationtreatment, the introduction of phosphorus in Fe2O3 significantly ameliorated the catalytic activity for the elimination of SDZ and the apparent rate constant (kobs) increased by 9.1 times. More importantly, the FexP particles exhibited magnetic property which is convenient for recycling use. This feature is very different from the previously reported TMPs catalytic materials. Besides, four types of reactive oxygen species (ROS) including sulfate radical (SO4−), hydroxyl radical (OH), singlet oxygen (1O2) and superoxide radical (O2−) were detected to play a key role in SDZ elimination by electron paramagnetic resonance (EPR) cooperated with radical quenching tests. This finding opened up an avenue for developing and utilizing TMPs catalytic materials in the environmental remediation.
