Ni2P Nanoparticles Research Articles

Controlled Hydrogenation of Alkynes Using Ni2P Nanoparticles Supported on Al2O3

Controlled Hydrogenation of Alkynes Using Ni2P Nanoparticles Supported on Al2O3

Enhanced photocatalytic hydrogen evolution by S-scheme heterojunction and metal phosphide in NiTiO3/Graphdiyne

A key strategy to improve photocatalytic reaction efficiency is to achieve effective separation and migration of photo-generated carriers. Heterojunctions and co-catalysts are essential for boosting charge separation and transfer, reducing activation energy, and providing active sites for surface redox reactions. Herein, we introduce a composite catalytic system based on NiTiO3, enhanced with Graphdiyne (GDY) and NiP, achieving a hydrogen production activity of 8.37 mmol g−1 h−1. This performance is attributed to the combined effects of S-scheme heterojunction formation and NiP nanoparticle generation through phosphorylation. The S-scheme heterojunction effectively separates electron-hole pairs, reducing charge transport distance. Additionally, NiP nanoparticles formed in situ promote faster charge separation from NiTiO3 and act as active sites to accelerate the reduction half-reaction. Consequently, NiTiO3/GDY-P exhibits higher light absorption, faster charge separation, and superior redox capacity compared to NiTiO3. This work presents an efficient, eco-friendly multiphase catalytic system based on an S-scheme heterojunction and metal phosphide.

Synthesis of Amorphous and Various Phase-Pure Nanoparticles of Nickel Phosphide with Uniform Sizes via a Trioctylphosphine-Mediated Pathway.

Nickel phosphides are of particular interest because they are highly active and stable catalysts for petroleum/biorefinery and hydrogen production. Despite their significant catalytic potential, synthesizing various phase-pure nickel phosphide nanoparticles of uniform size remains a challenge. In this work, we develop a robust trioctylphosphine (TOP)-mediated route to make highly uniform phase-pure Ni12P5, Ni2P, and Ni5P4 nanoparticles. The synthetic route forms amorphous Ni70P30 nanoparticle intermediates. The reactions can be stopped at the amorphous stage when amorphous particles are desired. The amount of P incorporation can be controlled by varying the ratio of TOP to Ni(II). The mechanism for composition control involves the competition of the kinetics of two processes: the addition of the reduced Ni and the incorporation of P into Ni. Uniform Ni70P30 amorphous nanoparticles can be generated at a high TOP-to-Ni(II) ratio, where the P incorporation kinetics is made to dominate. Ni70P30 can later be transformed into phase-pure Ni12P5, Ni2P, and Ni5P4 nanocrystals of uniform size. The transformation can be controlled precisely by modulating the temperature. A UV-vis study coupled with theoretical modeling reveals Ni(0)-TOPx complexes along the synthetic path. This approach may be expanded to create other metal compounds, potentially enabling the synthesis of uniform nanoparticles of a greater variety.

A Robust Synthesis of Co2P and Ni2P Nanocatalysts from Hexaethylaminophosphine and Phosphine-Enhanced Phenylacetylene Hydrogenation.

Metal-rich phases of general formula M2P have demonstrated interesting catalytic activity, e.g., for hydrogen evolution reaction and for hydrogenations in colloidal suspension. The production of well-crystallized nanoparticles of the M2P phase from commercial precursors on a large enough scale is not trivial as the existing routes generally require fairly high reaction temperatures and a large excess of the phosphorus source. Here, we selected a commercial aminophosphine, P(NEt2)3, as the phosphorus precursor (3 equiv or less) to develop a robust synthesis from CoCl2 (respectively NiCl2) that provided crystalline Co2P (respectively Ni2P) nanoparticles with high yields on a 9 mmol scale. Moreover, modification of the M2P nanoparticles via the addition of a molecular Lewis base is a promising route to trigger catalytic activity of the colloidal suspension at a lower temperature. For the hydrogenation of phenylacetylene catalyzed by Co2P and Ni2P nanoparticles, we showed that catalytic amounts of adequate phosphines, such as PnBu3 and also, in some instances, oleylamine, triggered a full conversion at lower temperatures than with the nanoparticles alone. We delineated the most efficient phosphines in the case of a Ni2P catalyst, using a stereoelectronic map of 13 phosphines.

Cocatalyst Embedded Ce-BDC-CeO2 S-Scheme Heterojunction Hollowed-Out Octahedrons With Rich Defects for Efficient CO2 Photoreduction.

Constructing heterojunction photocatalysts with optimized architecture and components is an effective strategy for enhancing CO2 photoreduction by promoting photogenerated carrier separation, visible light absorption, and CO2 adsorption. Herein, defect-rich photocatalysts (Ni2P@Ce-BDC-CeO2 HOOs) with S-scheme heterojunction and hollowed-out octahedral architecture are prepared by decomposing Ce-BDC octahedrons embedded with Ni2P nanoparticles and subsequent lactic acid etching for CO2 photoreduction. The hollowed-out octahedral architecture with multistage pores (micropores, mesopores, and macropores) and oxygen vacancy defects are simultaneously produced during the preparation process. The S-scheme heterojunction boosts the quick transfer and separation of photoinduced charges. The formed hollowed-out multi-stage pore structure is favorable for the adsorption and diffusion of CO2 molecules and gaseous products. As expected, the optimized photocatalyst exhibits excellent performance, producing CO with a yield of 61.6µmolh-1g-1, which is four times higher than that of the original Ce-BDC octahedrons. The X-ray photoelectron spectroscopy, scanning Kelvin probe, and electron spin resonance spectroscopy characterizations confirm the S-schematic charge-transfer route. The key intermediate species during the CO2 photoreduction process are detected by in situ Fourier transform infrared spectroscopy to support the proposed mechanism for CO2 photoreduction. This work presents a synthetic strategy for excellent catalysts with potential prospects in photocatalytic applications.

Nickel phosphide: the Effect of Phosphorus Content on the Activity and Stability toward Oxygen Evolution Reaction in Alkaline Medium.

In this work, a systematic study of the effect of the metal to phosphorus ratio in Ni-P nanoparticles on their catalytic activity with respect to the OER is reported. To this end, nickel phosphide nanoparticles are synthesized through two different synthesis routes, one involving in-situ phosphidation and one involving ex-situ phosphidation. In-situ phosphidation is performed via two steps route in a one-pot synthesis, in which Ni nanoparticles are formed at 220 ◦C, but not isolated, and then transformed to phase pure either Ni12P5 or Ni2P nanocrystallites. In the second synthesis method (ex-situ phosphidation), nickel nanoparticles with an excess amount of trioctylphosphine (TOP) as a capping agent were synthesized and separated from the solution, then subsequently annealed in three different atmospheres, leading to the formation of three types of NixPy viz.[NixPy-H2/Ar], [NixPy-Ar], and [NixPy -air ], [NixPy -air ] nanoparticles showed the best electrocatalytic activity among the annealed nanoparticles in Ar and H2/Ar but lower than Ni12P5 nanoparticles. However, [NixPy -air ] showed very high stability in comparison with other synthesized nanoparticles. Moreover, the effect of the adventitious and spiked Fe in the electrolyte was studied on the electrocatalytic activity of all synthesized nanoparticles.

Multiple strategies regulating the d-band center of Ni2P/NiFe2O4 @N-GTs hierarchical nanoarchitecture as efficient electrocatalyst for overall water splitting

The rational design of highly active electrocatalysts for water electrolysis remains challenging for green hydrogen utilization. Herein, guided by the correlation between the electroactivity and the d-band center (Ed), a novel hierarchical nanoarchitecture (Ni2P/NiFe2O4-VO@N-GTs) was fabricated, in which, Ni2P nanoparticles are grown on the oxygen vacancy-rich NiFe2O4 nanosheet arrays anchoring on N-doping graphene tubes. The results reveal that the multiple strategies including the vacancies and heterogeneous interface construction effectively induce the charge redistribution, and further adjust the Ed to the appropriate energy level, which endows the optimal balance between the adsorption and desorption ability of the catalyst to reaction intermediates, thus leading to the conspicuous electrocatalytic activity. Additionally, the hierarchical nanoarchitecture contributes to the exposure of more active sites, the efficiency of electron transfer, and the release of generated gas. Hence, Ni2P/NiFe2O4-VO@N-GTs presents superior bifunctional activity, especially a low overpotential of 194 mV at 10 mA cm−2 for OER. The corresponding overall water electrolyzer owns a lower cell voltage and long-term durability with continuously operating over 330 h at 100 mA cm−2, outperforming the most reported bifunctional electrocatalysts. This work presents an effective pathway for regulating the Ed through multiple strategies to improve the catalytic performance of catalysts.

Novel FeNiP–FeNi–C nanofiber as an outstanding electrocatalyst for oxygen evolution reaction

Developing stable, highly active, and economical non-precious metal catalysts for the oxygen evolution reaction (OER) has been highly demanded in the new energy field since it can meet the industrial demands of large-scale electrocatalytic water splitting. A novel FeP/Ni2P/Fe0.64Ni0.36/C (FeNiP–FeNi–C) nanofiber was prepared by electrospinning and high-temperature phosphating. Notably, the good dispersion of FeP, Ni2P, and FeNi alloy nanoparticles in the nanocarbon fiber greatly increased the number of electroactive sites, and the synergistic effect between the FeP/Ni2P heterogeneous interface and FeNi alloy significantly improved the inherent activity of each site. Moreover, the carbon nanofibers enhanced the long-term durability of the catalyst by preventing the corrosion of the FeP, Ni2P, and FeNi alloy particles. Therefore, the optimal FeNiP–FeNi–C catalyst revealed exceptionally high OER activity, with overpotentials of 364 mV and 236 mV at 50 mA cm−2 and 10 mA cm−2 respectively, and the slope of Tafel of 61.00 mV·dec−1. This catalyst performs significantly better than commercial RuO2 catalysts in alkaline electrolytes. The results of this study offer a novel perspective for the mass production of non-precious metal OER high-efficiency electrocatalysts.

Heat-induced aliquation and phosphating of nickel as efficient catalysts for hydrogen evolution in alkaline seawater

Developing electrolytic seawater catalysts with excellent performance is crucial for efficient hydrogen production. In this study, Ni2P nanoparticles anchored on NiMo oxides, denoted as NiMo-P, are synthesized through heat-induced aliquation and phosphating of Ni in the ammonium nickel molybdate. Physicochemical characterizations reveal that the abundant Ni2P nanoparticles are uniformly distributed on NiMo oxides. Electrochemical data reveal that a mere overpotential of 103 mV is sufficient to achieve −100 mA cm−2 in alkaline simulated seawater, which is significantly lower than that of Pt foil (179 mV) and commercial Pt/C (165 mV). This remarkable activity observed in NiMo-P may be due to the superior water dissociation activity and hydrogen desorption ability of the Ni2P nanoparticles, as calculated by density functional theory, which surpasses that of Pt. Meanwhile, the NiMo-P exhibits outstanding stability, as evidenced by the chronoamperometric curve. The current remains at 98.1% of its initial value after 500 h, which can be attributed to the etching-hydrolysis method that strengthens the catalyst-carrier interaction. Besides, the inherent repulsion toward chlorine ions at the cathode effectively avoids chemical corrosion. Importantly, when coupled with the previously reported anode, NiMo-P also exhibits exceptional performance in alkaline seawater.

Cation‐Induced Deep Reconstruction and Self‐Optimization of NiFe Phosphide Precatalysts for Hydrogen Evolution and Overall Water Splitting

AbstractSurface reconstruction that produces real active species for catalytic reactions generally occurs during electrocatalytic water splitting, but overcoming the reconstruction level‐mass activity‐stability trade‐off is a grand challenge. A cation‐doping in conjunction with a geometrical topology strategy is proposed to concurrently realize deep reconstruction and self‐optimization of FeNi phosphide nanoarrays during an electrochemical activation process. The doped Zn cation induces a deep reconstruction of FeNiP@Fe2P precatalyst by continuously dissolving Fe2P and re‐depositing as amorphous FeOOH that solders Ni2P nanoparticles, forming small ultra‐thin nanosheets with abundant amorphous‐crystalline interfaces for structural stability. Moreover, multichannel topology exhibits an unusual ability to optimize their morphology via finally evolving into multi‐microchannel tubular nanoarrays comprising of interconnected‐nanosheets with a very loose structure for enhanced electrolyte permeability, mass transfer, and accessibility of active sites. The reconstructed Zn‐Ni2P/FeOOH superstructure catalysts reach 10 mA cm−2 current density at an ultra‐low overpotential of 11 mV for hydrogen evolution reactions (HER). Impressively, when assembled as a two‐electrode cell with Zn‐FeNiP@Zn‐Fe2P as anode and Zn‐Ni2P/FeOOH as cathode, it delivers current densities of 10 mA cm−2 at a record low cell voltage of 1.40 V. This strategy provides a novel avenue to promote reconstruction for achieving high catalytic performance.

Ni-doped sites in yeast-derived catalysts for efficient electrochemical synthesis of hydrogen peroxide

The electrochemical synthesis of hydrogen peroxide (H2O2) via the 2-electron pathway of oxygen reduction reaction offers a green and on-site product. However, there remains an urgent need to develop cost-efficient electrocatalysts with H2O2 productivity that meets practical industrial-scale requirements. In this study, yeast-derived carbon material loaded with multiple Ni active sites achieved electrochemical synthesis of H2O2 at industrial current density. The precursor of heteroatom-doped carbon material was obtained through high-dispersed Ni(II) adsorption on yeast cells. By adjusting the pyrolysis temperature and Ni loading dosage, the carbon framework, pore structure, and Ni active sites within the obtained Ni/yeast were successfully regulated. Ni/yeast featured with highly active Ni single-atom sites, metallic Ni nanoparticles and Ni2P nanoparticles, enabling stable running for 10 h at 200 mA cm−2 in a flow cell. Ni/yeast exhibits remarkable H2O2 Faradaic efficiency of 94.6 % and a yield of 35.3 mol gcat−1h−1. The abundant pore structure and multiple Ni active sites within Ni/yeast provide promising avenues for manipulating heteroatom-doped carbon materials in H2O2 electrosynthesis.

Heterometallic Electrocatalysts Derived from High-Nuclearity Metal Clusters for Efficient Overall Water Splitting.

The development of cost-effective electrocatalysts with an optimal surface affinity for intermediates is essential for sustainable hydrogen fuel production, but this remains insufficient. Here we synthesize Ni2P/MoS2-CoMo2S4@C heterometallic electrocatalysts based on the high-nuclearity cluster {Co24(TC4A)6(MoO4)8Cl6}, in which Ni2P nanoparticles were anchored to the surface of the MoS2-CoMo2S4@C nanosheets via strong interfacial interactions. Theoretical calculations revealed that the introduction of Ni2P phases induces significant disturbances in the surface electronic configuration of Ni2P/MoS2-CoMo2S4@C, resulting in more relaxed d-d orbital electron transfers between the metal atoms. Moreover, continuous electron transport was established by the formation of multiple heterojunction interfaces. The optimized Ni2P/MoS2-CoMo2S4@C electrocatalyst exhibited ultralow overpotentials of 198 and 73 mV for oxygen and hydrogen evolution reactions, respectively, in alkaline media, at 10 mA cm-2. The alkali electrolyzer constructed using Ni2P/MoS2-CoMo2S4@C required a cell voltage of only 1.45 V (10 mA cm-2) to drive overall water splitting with excellent long-term stability.

Carbon-coated Ni2P nanoparticles coated on CNTs synthesized by an in-situ solid-state method for high-performance hybrid supercapacitors and lithium-ion batteries

The pursuit of electrode materials with excellent performance in both supercapacitors and lithium-ion batteries holds the potential to streamline the construction of hybrid electrochemical energy storage systems and contribute to cost reduction. In this paper, we introduce a novel nanocomposite—carbon-coated Ni2P nanoparticles coated on CNTs (CNTs@(Ni2P@C))—via an in-situ one-step solid-state method. This design not only prevents the aggregation of Ni2P nanoparticles with a size of 5–8 nm but also mitigates its volume change during charging and discharging cycles. Simultaneously, it establishes a rapid electron transfer pathway between CNTs and Ni2P nanoparticles, enhancing the electron transport kinetics within the synthesized nanocomposite. The synthesized CNTs@(Ni2P@C) nanocomposite exhibits high performance in both SCs and LIBs. An ultra-high specific capacity of 378.5 mAh g−1 (2725.2 F g−1) at 1 A g−1 and a good rate capacity (189.3 mAh g−1 at 20 A g−1) are achieved when used in supercapacitors. The hybrid supercapacitor device assembled using the synthesized nanocomposite exhibits a high specific capacity of 84.3 mAh g−1 at 1 A g−1 and excellent capacity retention of 92 % after 10,000 cycles. A high energy density of 67.47 Wh kg−1 can be delivered at a power density of 0.84 kW kg−1. When used in LIBs, the synthesized nanocomposite exhibits a reliable reversible specific capacity of 329 mAh g−1 at 0.1 A g−1 after 100 cycles and a high capacity retention of 90 % after 5000 cycles at 2.0 A g−1. The proposed in-situ solid-state method and the synthesized CNTs@(Ni2P@C) nanocomposite will strongly promote the development of difunctional electrode materials for supercapacitors and lithium-ion batteries.

Dispersed Nickel Phosphide Cocatalyst on Nb2O5 Ultrathin Nanosheets to Boost Photocatalytic CO2 Reduction

AbstractPhotocatalytic CO2 reduction holds great promise to solve energy shortage and global warming. Nb2O5 has demonstrated superiority in CO2 activation and selectivity regulation, but suffers from poor light absorption ability and fast carrier recombination. To tackle these problems, we designed and synthesized ultrathin Nb2O5 nanosheets which were decorated with tiny NiP nanoparticles as cocatalyst. In this way, light absorption range broadened, carrier migration distance reduced, charge transfer resistance decreased, and surface reaction kinetics promoted. Consequently, the as‐prepared NiP/Nb2O5 showed notably enhanced activity (148.7 μmol ⋅ g−1) and selectivity (82.1 %) towards CO, as well as remarkable stability. This work paves the way for cheap and earth abundant alternatives as cocatalysts and deepens the understanding of their functions in CO2 photoreduction.

A pillar-layered Ni2P-Ni5P4-CoP array derived from a metal-organic framework as a bifunctional catalyst for efficient overall water splitting.

Interfacial engineering emerges as a potent strategy for regulating the catalytic reactivity of metal phosphides. Developing a facile and cost-effective method to construct bifunctional metal phosphides for highly efficient electrochemical overall water splitting remains an essential and challenging issue. Here, a multiphase transition metal phosphide is constructed through the direct phosphorization of a Ni-Co metal-organic framework grown on nickel foam (Ni-Co-MOF/NF), which is prepared by utilizing nickel foam as conductive substrate and nickel source. The resulting transition metal phosphide manifests a pillar-layered morphology, wherein CoP, Ni2P, and Ni5P4 nanoparticles are embedded within each carbon sheet and these carbon sheets assemble into a pillar-shaped structure on the nickel foam (Ni2P-Ni5P4-CoP-C/NF). The heterogeneous Ni2P-Ni5P4-CoP-C/NF with multiple interfaces serves as a highly efficient bifunctional electrocatalyst with overpotentials of -100 mV and 293 mV in the hydrogen evolution reaction and oxygen evolution reaction, respectively, at 50 mA cm-2 in alkaline media. This superior catalytic performance should mainly be ascribed to its enriched active centers and multiphase synergy. When directly applied for alkaline overall water splitting, the Ni2P-Ni5P4-CoP-C/NF couple demonstrates satisfactory activity (1.55 V @10 mA cm-2) along with sustained durability over 18 hours. This method brings fresh enlightenment to the economical and controllable preparation of multi-metal phosphides for energy conversion.

Research on the preparation and performance of Ni2P@MOF composite nanomaterials.

The present study employed a solvothermal method utilizing triphenylphosphine and nickel acetylacetonate as precursors for phosphide preparation, followed by analysis and characterization. The Ni-MOF precursor was prepared using benzene diacid, triethylenediamine, and nickel sulfate as raw materials. Ni2P was introduced into the Ni-MOF precursor during its preparation while maintaining the synthesis conditions, allowing for the adsorption of Ni2P nanoparticles during Ni-MOF synthesis to produce Ni2P@MOF composite materials. The materials underwent individual testing for UV, magnetic, and microwave absorption properties. Magnetic testing results demonstrated that the incorporation of Ni2P led to an increase in the saturation magnetization (Ms) of Ni2P@MOFs compared to the Ni-MOF, thereby enhancing its electromagnetic loss capability. Microwave absorption property testing indicated that the Ni2P@MOFs exhibited enhanced dielectric and electromagnetic loss capabilities compared to the Ni-MOF, optimizing impedance matching properties and increasing effective absorption bandwidth compared to pure Ni2P materials.

Probing the Effect of Environments on the Stability of Ni2P Nanoparticle Electrocatalysts

Ni2P has been shown to be an effective catalyst for the hydrogen evolution reaction (HER), making it a promising replacement for Pt which is the current state of the art HER catalyst.1,2 H2 is a clean-energy critical fuel and chemical highlighted by the US Department of Energy’s “Hydrogen Shot,” which seeks to reduce “the cost of carbon-neutral hydrogen by 80% to $1 per 1 kg in 1 decade, highlighting the key role of hydrogen in implementing carbon-neutral solutions.”3 Ni2P is also a good or promising catalyst for other reactions, such as alcohol oxidation, hydrodesulfurization,4,5 nitrate reduction, and oxygen evolution reaction.6 However, Ni2P and other TMPs are susceptible to oxidation, which can lead to catalyst degradation and loss in certain conditions.7,8 Stability is an important part of catalysis, especially for achieving the goals of the Hydrogen Shot. Therefore, it is important to understand complex degradation mechanisms in order to better understand structure-activity relationships in these materials. In the present work, in situ Ni K-edge X-ray absorption spectroscopy (XAS) and ex situ P Kα and Kβ X-ray emission spectroscopy (XES) couple together to understand the degradation of Ni2P and show the effects of electrolyte pH, ligands, and air on Ni2P nanoparticles.5 nm Ni2P nanoparticles were synthesized by heating NiCl2 and tris(diethylamino)phosphine in oleylamine. The nanoparticles were drop cast onto carbon fiber paper electrodes and Si wafers or Au-coated wafers for P Kα and Kβ XES. Oleylamine ligands are removed by thermal annealing. Electrochemical experiments were conducted with a three-electrode cell using carbon fiber paper or Au-coated wafers deposited with Ni2P nanoparticles as working electrode, Ag/AgCl calibrated to the H2 redox couple as reference electrode, and graphite rod as counter electrode. P Kα and Kβ XES experiments were conducted inside a N2 glovebox to prevent unintentional air oxidation. Transmission-mode Ni K-edge XAS was conducted on a benchtop spectrometer.Upon exposure to air, as-synthesized Ni2P nanoparticles were studied via P Kα and Kβ XES. Results showed that the phosphide species converted to phosphate with analysis of intermediates well fit by a simple two-phase mixture. Phosphide:phosphate ratios were quantified using linear combination analysis, providing a powerful tool to analyze P speciation on various samples in an inert environment and with minimal loss of material, both advantages of this system over 31P magic angle spinning solid state nuclear magnetic resonance spectroscopy and X-ray photoelectron spectroscopy. Continued work looks at analyzing the effects of the ligand environment on the stability of nanoparticles in electrolytes spanning from acidic to basic pH. We hypothesize that ligands will significantly stabilize the nanoparticles against corrosion and that without ligands Ni2P readily converts to a nickel phosphate species upon exposure to electrolyte.References(1) Popczun, E. J.; McKone, J. R.; Read, C. G.; Biacchi, A. J.; Wiltrout, A. M.; Lewis, N. S.; Schaak, R. E. Nanostructured Nickel Phosphide as an Electrocatalyst for the Hydrogen Evolution Reaction. J. Am. Chem. Soc. 2013, 135 (25), 9267–9270. https://doi.org/10.1021/ja403440e.(2) Liu, P.; Rodriguez, J. A. Catalysts for Hydrogen Evolution from the [NiFe] Hydrogenase to the Ni2P(001) Surface: The Importance of Ensemble Effect. J. Am. Chem. Soc. 2005, 127 (42), 14871–14878. https://doi.org/10.1021/ja0540019.(3) Bullock, M.; More, K. Basic Energy Sciences Roundtable: Foundational Science for Carbon-Neutral Hydrogen Technologies (Report); DOESC Office of Basic Energy Sciences, 2022. https://doi.org/10.2172/1834317.(4) Layan Savithra, G. H.; Muthuswamy, E.; Bowker, R. H.; Carrillo, B. A.; Bussell, M. E.; Brock, S. L. Rational Design of Nickel Phosphide Hydrodesulfurization Catalysts: Controlling Particle Size and Preventing Sintering. Chem. Mater. 2013, 25 (6), 825–833. https://doi.org/10.1021/cm302680j.(5) Rodriguez, J. A.; Kim, J.-Y.; Hanson, J. C.; Sawhill, S. J.; Bussell, M. E. Physical and Chemical Properties of MoP, Ni2P, and MoNiP Hydrodesulfurization Catalysts: Time-Resolved X-Ray Diffraction, Density Functional, and Hydrodesulfurization Activity Studies. J. Phys. Chem. B 2003, 107 (26), 6276–6285. https://doi.org/10.1021/jp022639q.(6) Menezes, P. W.; Indra, A.; Das, C.; Walter, C.; Göbel, C.; Gutkin, V.; Schmeiβer, D.; Driess, M. Uncovering the Nature of Active Species of Nickel Phosphide Catalysts in High-Performance Electrochemical Overall Water Splitting. ACS Catal. 2017, 7 (1), 103–109. https://doi.org/10.1021/acscatal.6b02666.(7) Ha, D.-H.; Han, B.; Risch, M.; Giordano, L.; Yao, K. P. C.; Karayaylali, P.; Shao-Horn, Y. Activity and Stability of Cobalt Phosphides for Hydrogen Evolution upon Water Splitting. Nano Energy 2016, 29, 37–45. https://doi.org/10.1016/j.nanoen.2016.04.034.(8) Parra-Puerto, A.; Ng, K. L.; Fahy, K.; Goode, A. E.; Ryan, M. P.; Kucernak, A. Supported Transition Metal Phosphides: Activity Survey for HER, ORR, OER, and Corrosion Resistance in Acid and Alkaline Electrolytes. ACS Catal. 2019, 11515–11529. https://doi.org/10.1021/acscatal.9b03359.

Three-dimensionally ordered macroporous ZSM-5 zeolite supported high-dispersed Ni2P: Highly active catalyst for quinoline hydrodenitrogenation

Zeolite catalysts have shown significant advantages in hydrogenation reactions due to their ordered pore structure and abundant acid sites. Common zeolites exhibit pore accessibility limited to microporous states, which restricts their application in diffusion-limited processes. In this study, a steam-seeding-assisted colloidal crystal template (SSAC) method was used to prepare ZSM-5 zeolite with a three-dimensionally ordered macroporous (3DOM) structure, which was then loaded with nickel phosphide for hydrodenitrogenation reactions. SEM and TEM characterization demonstrated that the prepared zeolite material possessed a highly ordered 3DOM structure with interconnected macropores. XRD, FT-IR, and BET analysis indicated that the macroporous zeolite material exhibited a typical MFI structure, mesoporous channels, and a higher specific surface area. The high external surface area facilitated the formation of uniformly sized Ni2P nanoparticles on the zeolite surface. The introduction of macroporous structures also leads to suitable Brönsted acid and Lewis acid sites in zeolite materials. The resultant Ni2P/3DOMZSM-5 catalyst exhibited higher reaction rate constants and TOF (10.87×10−2 μmolg−1s−1 and 1.5×10−3s−1, respectively) compared to other zeolite catalysts and commercial catalysts.

Construction of NiP/Ni(OH)2/Ag-ZIF photocatalyst with 2-methylimidazole framework for rapid removal of tetracycline

Tetracycline (TC) is a kind of antibiotic that is difficult to be degraded by photocatalysis due to its stable molecular structure, and no ideal photocatalyst has been developed so far, thus developing a photocatalyst that can efficiently remove TC remains a challenge. In this work, a novel ternary photocatalyst of NiP/Ni(OH)2/Ag-ZIF (NNA) with 2 −Methylimidazole framework was constructed via a facile liquid phase reaction, in which the NiP is amorphous with particle size of about 3–5 nm, the Ni(OH)2 is nano-flake crystal with a one-dimensional diameter of about 200 nm, and the Ag-ZIF is a octahedral crystal with a side length of 4 µm. The NiP nano particles covered on the surface of Ni(OH)2 nanosheeps to form NiP/Ni(OH)2 heterojunction with flower-like structure and large BET area of 393.11 m2 g−1, which was further assembled with Ag-ZIF to form NiP/Ni(OH)2/Ag-ZIF composite with double heterojunction. The as-constructed NNA shows high removal capacity for TC, while 10 mg NNA was added into 100 mL 60 mg/L TC solution and exposed in visible light for 60 min, 91.3% of TC was removed. Meanwhile, the NNA shows good stability and reusability, which is attribute to the reversible of adsorption and desorption process of NiP/Ni(OH)2 for TC and the excellent photo-corrosion resistance of Ag-ZIF. The radical trapping and electron spin resonance (ESR) tests manifested that the superoxide radical (O2-) and the hydroxyl radical (·OH) play the key role in the degradation of TC.

Ni2P/Co2P as a highly efficient catalyst for enhancing the electrochemical performance of P-NiMoO4 for oxygen evolution reaction

A growing trend in electrocatalysis is to explore interfacial interactions and surface intermediate adsorption in highly efficient bimetallic phosphide catalysts for developing efficient oxygen evolution reactions (OER). In this work, Ni2P and Co2P nanoparticles (NPs) were distributed on P-modified NiMoO4 nanorods prepared by the hydrothermal procedure, which exhibited high catalytic activity and outstanding durability for the OER. By regulating the high interfacial contact between Ni2P, Co2P, and P-NiMoO4, the Ni2P and Co2P NPs reduced the electron density, thus optimizing the OER. Compared to the NiMoO4 NRs, the P-NiMoO4@Ni2P/Co2P electrocatalyst showed remarkable activity towards the OER owing to the strong electron interaction and synergistic effect among the three components. Consequently, the P-NiMoO4@Ni2P/Co2P electrode yielded significant OER activity, with an overpotential of 260 mV, a Tafel slope of 41 mV/dec, and 92.9% Faradaic efficiency. Furthermore, the P-NiMoO4@Ni2P/Co2P electrocatalyst demonstrated excellent stability (up to 50 h) for the OER, which was higher than those of the NiMoO4-based catalysts reported in the literature. Several factors contribute to the excellent OER activity, including electron transfer between Ni2P, Co2P, and P-NiMoO4, and the abundant active sites generated from their interfacial interactions. Therefore, this study presents a novel approach for developing highly efficient ternary electrocatalysts for the long-term electrocatalytic evolution of oxygen.