Search Results (18)

Transition metal phosphides (TMPs) show great potential as catalysts for the hydrogen evolution reaction (HER). FeP stands out as an efficient and cost-effective non-noble metal-based HER catalyst. However, FeP tends to aggregate and suffer from instability during the reaction. To tackle these challenges, we developed an efficient and straightforward approach to load metal-organic framework-derived N/P co-doped carbon-encapsulated FeP nanoparticles onto a nickel foam substrate (FeP@NPC/NF-450). This catalyst exhibits exceptional HER activity in 0.5 M H₂SO₄ and 1.0 M KOH solutions, with overpotentials of 68.3 mV and 106.1 mV at a current density of 10 mA cm⁻², respectively. Furthermore, it demonstrates excellent stability with negligible decay over 48 h in both acidic and alkaline solutions. The outstanding hydrogen evolution catalytic performance of FeP@NPC/NF-450 is mainly due to the N, P co-doped carbon matrix, which safeguards the FeP nanoparticles from aggregation and surface oxidation. Consequently, this enhances the availability of active sites during the hydrogen evolution reaction (HER), leading to improved stability. Moreover, introducing nickel foam offers a larger specific surface area and enhances charge transfer rates. This study provides a reference method for preparing stable and highly active electrocatalysts for hydrogen evolution. Full article

The significance and challenges of hydrotreatment processes for vegetable oils have recently become apparent, encompassing various reactions like decarbonylation, decarboxylation, and hydrogenation. Heterogeneous noble or transition metal catalysts play a crucial role in these reactions, offering high selectivity in removing oxygen and yielding desired hydrocarbons. Notably, both sulphided and non-sulphided catalysts exhibit effectiveness, with the latter gaining attention due to health and toxicity concerns associated with sulphiding agents. Nickel-based catalysts, such as NiP and NiC, demonstrate specific properties and tendencies in deoxygenation reactions, while palladium supported on activated carbon catalysts shows superior activity in hydrodeoxygenation. Comparisons between the performances of different catalysts in various hydrotreatment processes underscore the need for tailored approaches. Transition metal phosphides (TMP) emerge as promising catalysts due to their cost-effectiveness and environmental friendliness. Ultimately, there is an ongoing pursuit of efficient catalysts and the importance of further advancements in catalysis for the future of vegetable oil hydrotreatment. Full article

Modifying the electronic structure of a catalyst through interface engineering is an effective strategy to enhance its activity in the hydrogen evolution reaction (HER). Interface engineering is a viable strategy to enhance the catalytic activity of transition metal phosphides (TMPs) in the HER process. The interface-engineered FeP/NiP₂/Ni₅P₄/NiP multi-metallic phosphide nanoparticles confined in a N, P-doped carbon matrix was developed by a simple one-step low-temperature phosphorization treatment, which only requires 72 and 155 mV to receive the current density of 10 mA/cm² in acid and alkaline electrolyte, respectively. This enhanced performance can be primarily attributed to the heterointerface of FeP/NiP₂/Ni₅P₄/NiP multi-metallic phosphides, which promotes electron redistribution and optimizes the adsorption/desorption strength of H* on the active sites. Furthermore, the N, P-doped carbon framework that encapsulates the nanoparticles inhibits their aggregation, leading to an increased availability of active sites throughout the reaction. The results of this study open up a straightforward and innovative approach to developing high-performance catalysts for hydrogen production. Full article

Transition metal phosphides (TMPs) have been widely studied for water decomposition for their monocatalytic property for anodic or cathodic reactions. However, their bifunctional catalytic activity still remains a major challenge. Herein, hexagonal nickel-cobalt bimetallic phosphide nanoneedles with 1–3 μm length and 15–30 nm diameter supported on NF (Ni_xCo_2−xP NDs/NF) with adjusted electron structure have been successfully prepared. The overall alkaline water electrolyzer composed of the optimal anode (Ni_0.67Co_1.33P NDs/NF) and cathode (Ni_1.01Co_0.99P NDs/NF) provide 100 mA cm⁻² at 1.62 V. Gibbs Free Energy for reaction paths proves that the active site in the hydrogen evolution reaction (HER) is Ni and the oxygen evolution reaction (OER) is Co in Ni_xCo_2−xP, respectively. In the HER process, Co-doping can result in an apparent accumulation of charge around Ni active sites in favor of promoting HER activity of Ni sites, and ΔG_H* of 0.19 eV is achieved. In the OER process, the abundant electron transfer around Co-active sites results in the excellent ability to adsorb and desorb *O and *OOH intermediates and an effectively reduced ∆G_RDS of 0.37 eV. This research explains the regulation of electronic structure change on the active sites of bimetallic materials and provides an effective way to design a stable and effective electrocatalytic decomposition of alkaline water. Full article

Black phosphorus (BP), as a direct band gap semiconductor material with a two-dimensional layered structure, has a good application potential in many aspects, but the surface state of it is extremely unstable, especially that of single-layer black phosphorus. In this study, BP crystals and two-dimensional black phosphorus (2D BP) are prepared by a mechanical ball-milling–liquid-phase exfoliation method. The X-ray diffraction (XRD) spectrum and high-resolution transmission electron microscopy (HRTEM) results showed that red phosphorus (RP) successfully turned to BP by the mechanical ball-milling method. The spectrophotometric analysis has detected absorption peaks at 780 nm, 915 nm, and 1016 nm, corresponding to single, double, and three-layer BP bandgap emission. A simple solvothermal strategy is designed to synthesize in-plane BP/P-rich transition metal phosphide (TMP) heterostructures (BP/NiP₃) by defect/edge-selective growth of NiP₃ on the BP nanosheets. HRTEM analysis indicates that the metal ions are preferentially deposited on the defects of 2D BP such as edges and unsaturated sites, forming a 2D BP/NiP₃ in-plane heterojunction. Full article

Large-scale hydrogen (H₂) production is an essential gear in the future bioeconomy. Hydrogen production through electrocatalytic seawater splitting is a crucial technique and has gained considerable attention. The direct seawater electrolysis technique has been designed to use seawater in place of highly purified water, which is essential for electrolysis, since seawater is widely available. This paper offers a structured approach by briefly describing the chemical processes, such as competitive chloride evolution, anodic oxygen evolution, and cathodic hydrogen evolution, that govern seawater electrocatalytic reactions. In this review, advanced technologies in transition metal phosphide-based seawater electrolysis catalysts are briefly discussed, including transition metal doping with phosphorus, the nanosheet structure of phosphides, and structural engineering approaches. Application progress, catalytic process efficiency, opportunities, and problems related to transition metal phosphides are also highlighted in detail. Collectively, this review is a comprehensive summary of the topic, focusing on the challenges and opportunities. Full article

Hydrogen energy is regarded as an auspicious future substitute to replace fossil fuels, due to its environmentally friendly characteristics and high energy density. In the pursuit of clean hydrogen production, there has been a significant focus on the advancement of effective electrocatalysts for the process of water splitting. Although noble metals like Pt, Ru, Pd and Ir are superb electrocatalysts for the hydrogen evolution reaction (HER), they have limitations for large-scale applications, mainly high cost and low abundance. As a result, non-precious transition metals have emerged as promising candidates to replace their more expensive counterparts in various applications. This review focuses on recently developed transition metal phosphides (TMPs) electrocatalysts for the HER in alkaline media due to the cooperative effect between the phosphorus and transition metals. Finally, we discuss the challenges of TMPs for HER. Full article

The exploitation of electrocatalysts with high activity and durability for the hydrogen evolution reaction is significant but also challenging for future energy systems. Transition metal phosphides (TMPs) have attracted a lot of attention due to their effective activity for the hydrogen evolution reaction, but the complicated preparation of metal phosphides remains a bottleneck. In this study, a green fabrication method is designed and proposed to construct N, P co-doped graphene (NPG)-supported cobalt phosphide (Co₂P) nanoparticles by using DNA as both N and P sources. Thanks to the synergistic effect of NPG and Co₂P, the Co₂P/NPG shows effective activity with a small overpotential of 144 mV and a low Tafel slope of 72 mV dec⁻¹ for the hydrogen evolution reaction. This study describes a successful green synthesis strategy for the preparation of high-performance TMPs. Full article

Ternary transition metal phosphides (TTMPs) with two-dimensional heterointerface and adjustable electronic structures have been widely studied in hydrogen evolution reactions (HER). However, single-phase TMPs often have inappropriate H* adsorption energy and electronic transfer efficiency in HER. Herein, we utilized the heterogeneity in the crystal structure to design an efficient and stable catalyst from the NiCoP nanowire@NiCoP nanosheet on nickel foam (NW-NiCoP@NS-NiCoP/NF) for HER. Layered double hydroxides (LDHs) with a heterogeneous matrix on crystal surfaces were grown under different reaction conditions, and non-metallic P was introduced by anion exchange to adjust the electronic structure of the transition metals. The hierarchical structure of homologous NiCoP/NF from the LDH allows for a larger surface area, which results in more active sites and improved gas diffusion. The optimized NW-NiCoP@NS-NiCoP/NF electrode exhibits excellent HER activity, with an overpotential of 144 mV, a Tafel slope of 84.2 mV dec⁻¹ at a current density of 100 mA cm⁻² and remarkable stability for more than 500 h in 1.0 M KOH electrolyte. This work provides ideas for elucidating the rational design of structural heterogeneity as an efficient electrocatalyst and the in situ construction of hierarchical structures. Full article

Green hydrogen energy has captivated researchers and is regarded as a feasible option for future energy-related aspirations. The emerging awareness of renewable energy-driven hydrogen generation and carbon dioxide reduction calls for the use of unconventional schematic tools in the fabrication of nanocatalyst systems. Transition metal phosphides are state-of-art, cost-effective, noble-metal-free materials that have been comprehensively examined for sustainable energy-driven applications. Recent reports on these advanced functional materials have cemented their candidature as high-performance catalytic systems for hydrogen production and for carbon dioxide conversion into value-added chemical feedstock. Bimetallic NiCoP (238.2 mmol g⁻¹ h⁻¹) exhibits top-notch catalytic competence toward photocatalytic HER that reveals the energy-driven application of a pristine class of TMPs, whereas heterostructured Ni₂P/CdS was found to be fit for photochemical CO₂ reduction, as well as for HER. On the other hand, pristine Ni₂P was recently ascertained as an efficient electrocatalytic system for HER and CO₂RR applications. A wide array of physicochemical modulations, such as compositional and structural engineering, defect generation, and facet control, have been used for improving the catalytic efficiency of transition metal phosphide nanostructures. In this review, we succinctly discuss the proficiency of transition metal phosphides in green hydrogen production and carbon dioxide conversion via photochemical and electrochemical pathways. We detail the significance of their structural properties and brief the readers about the synthetic advancements without deviating from our goal of summarizing the recent achievements in energy-driven applications. Full article

The hydrogen evolution reaction (HER) is a developing and promising technology to deliver clean energy using renewable sources. Presently, electrocatalytic water (H₂O) splitting is one of the low-cost, affordable, and reliable industrial-scale effective hydrogen (H₂) production methods. Nevertheless, the most active platinum (Pt) metal-based catalysts for the HER are subject to high cost and substandard stability. Therefore, a highly efficient, low-cost, and stable HER electrocatalyst is urgently desired to substitute Pt-based catalysts. Due to their low cost, outstanding stability, low overpotential, strong electronic interactions, excellent conductivity, more active sites, and abundance, transition metal tellurides (TMTs) and transition metal phosphides (TMPs) have emerged as promising electrocatalysts. This brief review focuses on the progress made over the past decade in the use of TMTs and TMPs for efficient green hydrogen production. Combining experimental and theoretical results, a detailed summary of their development is described. This review article aspires to provide the state-of-the-art guidelines and strategies for the design and development of new highly performing electrocatalysts for the upcoming energy conversion and storage electrochemical technologies. Full article

It is critical and challenging to develop high performance transition metal phosphides (TMPs) electrocatalysts for oxygen evolution reaction (OER) to address fossil energy shortages. Herein, we report the synthesis of Co₂P embedded in N-doped porous carbon (Co₂P@N-C) via a facile one-step strategy. The obtained catalyst exhibits a lower overpotential of 352 mV for OER at a current density of 10 mA cm⁻² and a small Tafel slope of 84.6 mV dec⁻¹, with long-time reliable stability. The excellent electrocatalytic performance of Co₂P@N-C can be mainly owed to the synergistic effect between the Co₂P and highly conductive N-C substrate, which not only affords rich exposed active sites but also promotes faster charge transfer, thus significantly promoting OER process. This work presents a promising and industrially applicable synthetic strategy for the rational design of high performance nonnoble metal electrocatalysts with enhanced OER performance. Full article

Polymetallic transition metal phosphides (TMPs) exhibit quasi-metallic properties and a high electrical conductivity, making them attractive for high-performance hybrid supercapacitors (HSCs). Herein, a nanohoneycomb (NHC)-like FeNi layered double hydroxide (LDH) array was grown in situ on 3D current collector nickel foam (NF), which is also the nickel source during the hydrothermal process. By adjusting the amount of NaH₂PO₂, an incomplete phosphated FeNi(OH/P) nanosheet array was obtained. The optimized FeNi(OH/P) nanosheet array exhibited a high capacity up to 3.6 C cm⁻² (408.3 mAh g⁻¹) and an excellent long-term cycle performance (72.0% after 10,000 cycles), which was much better than FeNi LDH’s precursor. In addition, the hybrid supercapacitor (HSC) assembled with FeNi(OH/P) (cathode) and polypyrrole (PPy/C, anode) achieved an ultra-high energy density of 45 W h kg⁻¹ at a power density of 581 W kg⁻¹ and an excellent cycle stability (118.5%, 2000 cycles), indicating its great potential as an HSC with a high electrochemical performance. Full article

Hydrodeoxygenation (HDO) reaction is a route with much to offer in the conversion and upgrading of bio-oils into fuels; the latter can potentially replace fossil fuels. The catalyst’s design and the feedstock play a critical role in the process metrics (activity, selectivity). Among the different classes of catalysts for the HDO reaction, the transition metal phosphides (TMP), e.g., binary (Ni2P, CoP, WP, MoP) and ternary Fe-Co-P, Fe-Ru-P, are chosen to be discussed in the present review article due to their chameleon type of structural and electronic features giving them superiority compared to the pure metals, apart from their cost advantage. Their active catalytic sites for the HDO reaction are discussed, while particular aspects of their structural, morphological, electronic, and bonding features are presented along with the corresponding characterization technique/tool. The HDO reaction is critically discussed for representative compounds on the TMP surfaces; model compounds from the lignin-derivatives, cellulose derivatives, and fatty acids, such as phenols and furans, are presented, and their reaction mechanisms are explained in terms of TMPs structure, stoichiometry, and reaction conditions. The deactivation of the TMP’s catalysts under HDO conditions is discussed. Insights of the HDO reaction from computational aspects over the TMPs are also presented. Future challenges and directions are proposed to understand the TMP-probe molecule interaction under HDO process conditions and advance the process to a mature level. Full article

Proton Exchange Membrane (PEM) water electrolysis (WE) produces H₂ with a high degree of purity, requiring only water and energy. If the energy is provided from renewable energy sources, it releases “Green H₂”, a CO₂-free H₂. PEMWE uses expensive and rare noble metal catalysts, which hinder their use at a large industrial scale. In this work, the electrocatalytic properties of Transition Metal Phosphides (TMP) catalysts supported on Carbon Black (CB) for Hydrogen Evolution Reaction (HER) were investigated as an alternative to Platinum Group Metals. The physico-chemical properties and catalytic performance of the synthesized catalysts were characterized. In the ex situ experiments, the 25% FeP/CB, 50% FeP/CB and 50% CoP/CB with overpotentials of −156.0, −165.9 and −158.5 mV for a current density of 100 mA cm⁻² showed the best catalytic properties, thereby progressing to the PEMWE tests. In those tests, the 50% FeP/CB required an overpotential of 252 mV for a current density of 10 mA cm⁻², quite close to the 220 mV of the Pt catalyst. This work provides a proper approach to the synthesis and characterization of TMP supported on carbon materials for the HER, paving the way for further research in order to replace the currently used PGM in PEMWE. Full article