Red Phosphorus Research Articles

Nacre-Inspired Structure Enables Ultrahigh 'Strong-Tough' Design of Phosphorus Anode.

Red phosphorus anode, attributed to its high specific capacity of 2596 mAh g-1, is expected to improve the energy density of Na-ion batteries. However, the P anode currently is unsatisfactory for practical usage due to the large volume expansion beyond 300 %, which brings out uncontrolled brittle failure. To address this challenge, we here design a nacre-like phosphorus anode by resilient graphene oxide staggered together. The staggered structure simultaneously offers mechanical strength and interwoven toughness. Finite element modeling reveals that the sodiation stress from P nanoparticles will be transferred into interlayer pillars as the elastic medium to release sodiation stress. The prepared anode achieves an ultrahigh areal capacity of 13 mAh cm-2 at a mass loading of 5.8 mg cm-2. Notably, the volume change of the anode is limited to approximately 8.1 % at full sodiation, significantly lower than that of the traditional phosphorus electrodes.

All-solid-state red phosphorus/RGO/WO3 Z-scheme heterostructure for photocatalytic overall water splitting

Red phosphorus’s (Red P) photocatalytic overall water splitting activity is limited by rapid charge recombination. In this case, Red P/RGO/WO3, an all-solid-state Z-scheme heterostructure, was created by simply dispersing, mixing, and heating Red P, WO3, and graphene oxide (GO). Among them, Reduced GO (RGO) facilitated the Z-scheme charge transmission between Red P and WO3. Achieving the space separation between electrons stored in Red P’s conduction band and holes accumulated in WO3′s valence band would prolong the lifespan of photogenerated carriers and increase their redox capacity, which will increase photocatalytic activity. When exposed to visible light, Red P/RGO/WO3 demonstrated an effective overall water splitting activity, producing 287.00 μmol h−1 g−1 of H2, which is around 2.5 times more than Red P. This study constructs Z-scheme heterostructures as a possible means of enhancing Red P’s photocatalytic overall water splitting activity.

Complex therapy of mineral metabolism in service dogs

The high physical and functional load of service dogs causes changes not only in body systems, but also in metabolism as a whole. An integrated approach to the study of this problem and the search for a pharmacotherapeutic solution will allow us to correct biochemical changes in the body of dogs and improve the performance and quality of life of animals. The purpose of the study was to study the therapeutic effectiveness of a complex of metabolic stimulants for the correction of mineral metabolism. For the study, 16 service dogs were selected in the area of application of the general search profile, belonging to the Ministry of Internal Affairs of Russia in the Altai Territory. Blood was drawn at the beginning and end of the study to analyze red blood cell counts, hemoglobin, hematocrit, glucose, cholesterol, triglycerides, iron, magnesium, zinc, calcium, phosphorus, and chloride. According to the results of the study, it was established that a violation of homeostasis in service dogs was accompanied by changes in some indicators of red blood, as well as pathology of mineral metabolism. After a course of pharmacotherapy, an increase in red blood cells (up to 7.9±0.22*×1012 cells/l) and hemoglobin (up to 141.66±7.32 g/l) was observed in dogs. Carbohydrate metabolism in both groups was characterized by hypoglycemia (3.34±0.21–3.43±0.28 mmol/l). By the end of the study, the glucose level in the experimental group significantly increased by 31.4% relative to the animals in the control group. By the end of the study, cholesterol levels in dogs in the experimental group decreased more rapidly compared to the control group. The study of the dynamics of mineral metabolism indicators revealed a significant increase in iron levels in the experimental group of animals (up to 25.3±1.9 µmol/l), which was 22.8% higher than the control value. Changes in other indicators of mineral metabolism did not differ significantly between the groups, although dogs receiving stimulating therapy showed positive dynamics of changes in mineral metabolism indicators. The use of a complex of metabolic stimulants “Suiferrovita”, “Strolitin”, “Amber Acid” stabilized red blood counts and contributed to the development of a tendency towards the restoration of mineral metabolism.

Synthesis of the Bulky Phosphanide [P(SiiPr3)2]- and Its Stabilization of Low-Coordinate Group 12 Complexes.

Here, we report an improved synthesis of the bulky phosphanide anion [P(SiiPr3)2]- in synthetically useful yields and its complexation to group 12 metals. The ligand is obtained as the sodium salt NaP(SiiPr3)2 1 in a 42% isolated yield and a single step from red phosphorus and sodium. This is a significantly higher-yielding and safer preparation compared to the previously reported synthesis of this ligand, and we have thus applied 1 to the synthesis of the two-coordinate complexes M[P(SiiPr3)2]2 (M = Zn, Cd, Hg). These group 12 complexes are all monomeric and with nonlinear P-M-P angles in the solid state, with DFT calculations suggesting that this bending is due to the steric demands of the ligand. Multinuclear NMR spectroscopy revealed complex second-order splitting patterns due to strong PP' coupling. This work demonstrates that the synthesis of 1 is viable and provides a springboard for the synthesis of low-coordinate complexes featuring this unusual bulky ligand.

Two P, Ten P, White P, Red P: Mechanistic Exploration of the Oligomerization of Red Phosphorus from Diphosphorus with the Ab Initio Nanoreactor.

Phosphorus is critical to humans on many fronts, yet we do not have a mechanistic understanding of some of its most basic transformations and reactions─namely the oligomerization of white phosphorus to red. With heat or under ultraviolet (UV) exposure, it has been experimentally demonstrated that white phosphorus dissociates into diphosphorus units which readily form red phosphorus. However, the mechanism of this process is unknown. The ab initio nanoreactor approach was used to explore the potential energy surface of phosphorus clusters. Density functional theory and metadynamics simulations were used to characterize potential reaction pathways. A mechanism for oligomerization is proposed to take place via diphosphorus additions at π-bonds and weak σ-bonds through three membered ring intermediates. Downhill paths through P6 and P8 clusters eventually result in P10 clusters that can oligomerize into red phosphorus chains. The initial, rate limiting step for this process has an energy barrier of 24.2 kcal/mol.

Si-P-Cu internally bonded anode: An innovative strategy for low-cost and high-performance pseudocapacitive Li-ion storage

Maintaining the structural integrity of silicon and phosphorus anodes during the Li+ insertion and extraction cycles poses a significant challenge. Inspired by the natural process of plant roots anchoring into soil, we present a simple yet effective method for integrating a SiP anode into the copper current collector. This approach involves subjecting readily available and cost-effective micrometre-sized silicon particles (50–150 μm) and red phosphorus to mechanochemical treatment. Subsequently, the resulting Si/P composite is coated onto copper foil and subjected to annealing treatment, resulting in the formation of an integrated structure, incorporating Cu3Si, Cu3P, and P-doped Si, firmly established within the copper current collector. The electrode obtained (BM-Si@P/Cu-350), promoted by a crosslinked (polyimide) PI binder, outperforms not only the ball-milled Si and red P but also the same electrode in which the annealing process is absent (BM-Si@P/Cu-100). During the mechanochemical treatment, red P acts as both the doping agent and a lubricant, facilitating the grinding of the Si particles into P-doped Si particles in the range of predominantly 200–300 nm; while during the thermal treatment, Si plays a key role in preventing excessive interaction between the P and the Cu current collector. Instead, a tailored rooting of the active material into the current collector is achieved through the formation of Cu3P and Cu3Si phases, not only increasing the mechanical stability of the electrode to endure volume changes during cycling and limit developing cracks, but also enhancing the electrical conductivity of the system. This article suggests a simple and potentially low-cost strategy for the utilization of highly available micrometre-sized silicon and red-P for Li-ion storage applications.

High‐abundance and low‐cost anodes for sodium‐ion batteries

AbstractNowadays, sodium‐ion batteries are considered the most promising large‐scale energy storage systems (EESs) due to the low cost and wide distribution of sodium sources as well as the similar working principle to lithium‐ion batteries (LIBs). Therefore, screening suitable materials with high abundance, low cost, and excellent reliability and modified with different strategies based on them is the key point for the development of sodium‐ion batteries (SIBs). In addition, the ideal anodes with high abundance, and low cost elements also greatly influence the cost of SIB systems, determining the large‐scale application. Herein, recent advances in carbon, iron, manganese, and phosphorus‐based anodes of various types, such as hard carbon, iron oxides, manganese oxides, and red phosphorus, are highlighted. The various sodium storage mechanisms and structure‐function properties for these four types of materials are summarized and analyzed in detail. Considering the commercial profits that the EESs can bring and their suitability for mass electrode manufacturing, the participation of high‐abundance and low‐cost elements such as Fe, Mn, C, and P is convincing and encouraging.

In Situ Construction of Crumpled Ti3C2Tx Nanosheets Confined S-Doping Red Phosphorus by Ti-O-P Bonds for LIBs Anode with Enhanced Electrochemical Performance.

Red phosphorus (RP) with a high theoretical specific capacity (2596 mA h g-1) and a moderate lithiation potential (∼0.7 V vs Li+/Li) holds promise as an anode material for lithium-ion batteries (LIBs), which still confronts discernible challenges, including low electrical conductivity, substantial volumetric expansion of 300%, and the shuttle effect induced by soluble lithium polyphosphide (LixPPs). Here, S-NRP@Ti3C2Tx composites were in situ prepared through a phosphorus-amine-based method, wherein S-doped red phosphorus nanoparticles (S-NRP) grew and anchored on the crumpled Ti3C2Tx nanosheets via Ti-O-P bonds, constructing a three-dimensional porous structure which provides fast channels for ion and electron transport and effectively buffers the volume expansion of RP. Interestingly, based on the results of adsorption experiments of polyphosphate and DFT calculation, Ti3C2Tx with abundant oxygen functional groups delivers a strong chemical adsorption effect on LixPPs, thus suppressing the shuttle effect and reducing irreversible capacity loss. Furthermore, S-doping improved the conductivity of red phosphorus nanoparticles, facilitating Li-P redox kinetics. Hence, the S-NRP@Ti3C2Tx anode demonstrates outstanding rate performance (1824 and 1090 mA h g-1 at 0.2 and 4.0 A g-1, respectively) and superior cycling performance (1401 mAh g-1 after 500 cycles at 2.0 A g-1).

Front Cover: Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre‐Anchored Ru Single Atoms in Defect and Interface Engineering

Front Cover: Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre‐Anchored Ru Single Atoms in Defect and Interface Engineering

Front Cover: Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre‐Anchored Ru Single Atoms in Defect and Interface Engineering

Front Cover: Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre‐Anchored Ru Single Atoms in Defect and Interface Engineering

Bimetallic MoFe phosphide catalysts for the hydrogen evolution reaction

In this work, highly efficient and stable (bi)metallic phosphides were prepared by a facile, flexible, and controllable sol-gel method followed by sintering. This novel approach allowed to avoid complicated and dangerous phosporization using, e.g. red phosphorus. The doping of the MoP catalysts with Fe was used to further boost their catalytic performance. Monometallic MoP and Mo3P, as well as bimetallic MoFeP were tested in both acidic and alkaline environments and showed remarkable results. The incorporation of Fe enabled the creation of a scalable and cost-effective catalyst for the hydrogen evolution reaction due to the synergy between Fe and Mo in the bimetallic phosphides. Using MoFeP for catalysing the hydrogen evolution reaction, overpotentials of only -132 mV (in an acidic medium) and -142 mV (in an alkaline medium) were needed to reach current density of -10 mA.cm−2, indicating the possibility of use this catalyst in a large pH range. Its high catalytic activity was maintained even at current density of -100 mA.cm−2 as documented by overpotentials of -202 mV and -246 mV in acid and alkaline environment, respectively. This, along with excellent stability and durability confirms its promising potential for incorporation into industrially relevant applications. The experimental data were confirmed by computational (DFT) results, showcasing that incorporation of Fe caused an increase in the number of active sites with Gibbs adsorption energy close to zero.

Fluorine Doping Modulating Pore Structure and Adsorption Capability of Carbon Matrix Boosting Potassium Storage Performance of Red Phosphorus Anode

AbstractThe application of alloying‐typed red phosphorus (red P) anode in potassium‐ion batteries (KIBs) with ultra‐high theoretical capacity is hindered by the limited capacity and fast capacity decay due to poor electronic conductivity and huge volume change. Herein, a facile and efficient strategy of fluorine (F) doping is innovatively developed to modulate the pore structure of carbon matrix (F‐CNS) to encapsulate red P with enhanced potassium storage capability. Theoretical calculations reveal that F doping induces additional defects within the carbon layer, which facilitates P4 molecules embedding into the F‐doping‐induced micropores, enhances the adsorption ability toward K atoms and P4 molecules, and improves electrochemical kinetics assisted with more charge transfer obtained from the electron density difference, thus enabling robust potassium storage capability for such unique Red P@F‐CNS anode. Accordingly, the Red P@F‐CNS anode demonstrates outstanding cycling stability (90% capacity retention after 800 cycles at 2A g−1), and the potassium‐ion full cell (Red P@F‐CNS//KFeHCF) exhibits exceptional long‐term cycling performance (129 mAh g−1 after 2500 cycles at 5 A g−1 with only 0.014% decay per cycle). In situ characterizations confirm the superior structural integrity of the carbon‐based matrix. This study offers a rational design principle for engineering high‐performance carbon‐supported alloying‐typed anodes for KIBs.

Controllable preparation of red phosphorus nanoribbons for enhanced photocatalytic degradation of Methyl Orange and Tetracycline.

Nanoribbons (NRs), leveraging the flexibility of one-dimensional materials and the expansive surface area of two-dimensional materials, offer heightened exposure to edge sites and superior charge transfer rates. Consequently, they present promising prospects within the domain of photocatalysis. Crystalline red phosphorus (cRP), dcharacterized by its layered and fibrous structure, lends itself readily to the production of nanoribbons. Our study demonstrates a robust method for achieving high-yield, high-quality cRP by concurrently introducing mineralizing agent I2 and Si wafers into the Chemical Vapor Transport (CVT) synthesis process. Through ultrasound assistance, we transformed high-quality cRP into crystalline red phosphorus nanoribbons (cRP NRs) with an average thickness ranging from 7.5 to 17.5nm and an average width between 75 and 175nm. cRP NRs (I2 and Si) showcased impressive degradation capabilities towards Methyl Orange (MO) and Tetracycline (TC), achieving a remarkable 99% degradation of MO within 18min under the simulated visible-light irradiation. The reactive species capturing experiments confirmed that ·O2- was the primary active agent responsible for the photocatalytic degradation of MO.

Construction of two-dimensional heterojunctions based on metal-free semiconductor materials and Covalent Organic Frameworks for exceptional solar energy catalysis

Covalent organic frameworks (COFs) are newly developed crystalline substances that are garnering growing interest because of their ultra-high porosity, crystalline nature, and easy modified architecture, showing promise in the field of photocatalysis. However, it is difficult for pure COFs materials to achieve excellent photocatalytic hydrogen production due to their severe carrier recombination problems. To mitigate this crucial issue, establishing heterojunction is deemed an effective approach. Nonetheless, many of the metal-containing materials that have been used to construct heterojunctions with COFs own a number of drawbacks, including small specific surface area and rare active sites (for inorganic semiconductor materials), wider bandgaps and higher preparation costs (for MOFs). Therefore, it is necessary to choose metal-free materials that are easy to prepare. Red phosphorus (RP), as a semiconductor material without metal components, with suitable bandgap, moderate redox potential, relatively minimal toxicity, is affordable and readily available. Herein, a range of RP/TpPa-1-COF (RP/TP1C) composites have been successfully prepared through solvothermal method. The two-dimensional structure of the two materials causes strong interactions between the materials, and the construction of heterojunctions effectively inhibits the recombination of photogenic charge carrier. As a consequence, the 9% RP/TP1C composite, with the optimal photocatalytic ability, achieves a photocatalytic H2 evolution rate of 6.93 mmol g−1 h−1, demonstrating a 10.19-fold increase compared to that of bare RP and a 4.08-fold improvement over that of pure TP1C. This article offers a novel and innovative method for the advancement of efficient COFs-based photocatalysts.

Flame-retarded and reinforced ethylene vinyl acetate copolymer with microencapsulated expandable graphite and microencapsulated red phosphorus

Simultaneously elevating fire safety and mechanical property is of great significance in flame retardation of polymers. Herein, a series of ethylene vinyl acetate (EVA) composites flame-retarded by expandable graphite (EG) were prepared and studied respecting their fire-retardant, mechanical, rheological and electrical properties. Results evince that combination of microencapsulated expandable graphite/microencapsulated red phosphorus (MEG/MRP) shows efficient fire-retarding effect on EVA in that adding merely 8 wt.% MEG/MRP can raise the polymer's limiting oxygen index to 26.6 % and UL-94 test to V-0 rating, whereas up to 20 wt.% EG and 10 wt.% EG/MRP are required for EVA to attain V-0 rating, respectively. The high efficiency is caused by more sizeable expansion ratio of MEG and high-quality expanded char resulting from MEG/MRP. Proper crosslinking of EVA matrix can augment strength and elasticity of EVA/MEG/MRP composite without lowering its fire retardance. Overall, the crosslinked EVA/MEG/MRP composite with 8 wt.% MEG/MRP shows good fire safety and mechanical property concurrently in contrast with virgin EVA.

Enhanced electrochemical cyclability of composite sodium metal anode with inorganic-rich solid electrolyte interphase

The practical application of sodium (Na) metal anode in rechargeable batteries is impeded by inferior electrochemical properties and safety hazards arising from uneven Na plating/stripping behaviors. The Na-ion diffusion within the solid electrolyte interphase (SEI) plays a pivotal role in influencing these behaviors and the electrochemical performance of the Na metal anode. In this study, we leveraged the spontaneous reaction between red phosphorus (P) and metallic Na to fabricate a Na/Na3P (NNP) composite foil using a straightforward folding and mechanical rolling method at room temperature. The in-situ formed Na3P phase fosters the formation of an inorganic-rich SEI layer with high ionic conductivity, effectively enhancing the Na-ion diffusion kinetics and curbing the formation of Na dendrites. Moreover, the Na3P present in the NNP composite can continually replenish the functional component and promptly repair the fracture of the SEI layer, thereby ensuring the stability of its structure and properties. Consequently, the NNP composite electrode significantly extends the Na plating/stripping cyclic lifespan compared to a bare Na anode. As a demonstration, the Na3V2(PO4)3||NNP full cell exhibits stable performance over 400 cycles with 96.7 % capacity retention at 5C. This work paves the way for designing stable SEI layers with fast ion diffusion capability for alkali metal anodes, and the findings are anticipated to propel the development of alkali metal batteries.

Comprehensive performance evaluation of HGM hybrid modified resins: Excellent high resistivity terahertz shielding and impact energy absorption properties

AbstractThe development of electronic fuze has placed higher demands on encapsulation resins, which are required to provide not only insulation and protection, but also higher impact resistance and good electromagnetic shielding performance. A new composite material consisting of hollow glass microspheres (HGM) and modified epoxy resin was developed. This material exhibits significant electromagnetic shielding capabilities for terahertz (THz) waves, as well as superior impact energy absorption properties. Bisphenol A‐type epoxy resin (E‐44) was modified using Al(OH)3, red phosphorus, carbon black, and SiO2, and the material properties were optimized by adjusting the HGM content. The electromagnetic shielding effectiveness and impact energy absorption of the composite material in the THz band were comprehensively tested using THz time‐domain spectroscopy and split Hopkinson pressure bar testing systems. Additionally, a comprehensive evaluation of the mechanical and dielectric properties, thermal conductivity, and thermal stability of the material was conducted. The results showed that the electromagnetic shielding effect of 60 vol.% HGM hybrid‐modified resins was the best, reaching 43.78 dB. The 20 vol.% HGM hybrid‐modified resins not only has a specific absorption energy of 18.51 J/cm3, but also has the best overall performance. This work has advanced the design and development of multifunctional and impact‐resistant potting epoxy resins.

Joint Time-Frequency Signal Analysis of Li-Ion Batteries

Measurements acquired from batteries, such as voltage-time and capacity-time signals, offer valuable insights into their cyclability performance. While analyzing these signals in the time domain provides an understanding of global characteristics, scrutinizing local behavior is crucial for detecting issues like battery fading. In this context, we delve into the application of short-time Fourier transform for time-frequency deconstruction of galvanostatic charge/discharge signals, using lithium-sulfur batteries as an illustrative example. Spectrograms resulting from this analysis unveil the evolving frequency content of signals throughout the battery's lifespan, facilitating the identification of critical changes in the response and early detection of issues leading to fading and potential default. Simultaneously, the stability analysis of the dynamic response of red phosphorus and sulfide polyacrylonitrile (RP-SPAN) composite, a promising anode material for lithium batteries, can also be studied using Fourier transform analysis. Our study employs transfer function stability analysis, Kramers-Kronig integral relations, and differential capacity analysis to assess the cell's behavior in both frequency and time domains. Parameters such as stationarity, stability, linearity, dissipation, and degradation are scrutinized over extended charge/discharge cycles. Results reveal a highly nonlinear and time-variant system at low frequencies, aligning with the observed 0.21% average capacity loss per cycle. Our results indicate that short-time Fourier transform could provide insightful information for analyzing battery health.

Hierarchical Porous Carbon Supported Co2P2O7 Nanoparticles for Oxygen Evolution and Oxygen Reduction in a Rechargeable Zn-Air Battery.

The oxygen reduction/evolution reaction (ORR/OER) represents a pivotal process in metal-air batteries; however, it is constrained by the limitations of slow kinetics. Nevertheless, the creation of long-lasting and bifunctional catalysts represents a significant challenge. This study presents a series of hierarchical porous carbon-supported cobalt pyrophosphate (Co2P2O7-N/C-T) catalysts, prepared through the pyrolysis of porphyrin-based NTU-70 nanosheets with red phosphorus at varying temperatures. The Co2P2O7-N/C-800 not only demonstrates remarkable OER performance with an overpotential of only 290 mV at a current density of 10 mA cm-2 in 1 M KOH, but also exhibits an excellent ΔE of 0.74 V in 0.1 M KOH, which is lower than that of Pt/C + RuO2 (0.76 V). The utilization of Co2P2O7-N/C-800 as an air cathode in a rechargeable Zn-air battery (ZAB) results in a stable discharge voltage plateau of 1.405 V and a high gravimetric energy density of 801.2 mA h gZn-1. This work presents a promising strategy for the design of efficient bifunctional catalysts and demonstrates the critical importance of the interplay between the active center and the supported hierarchical porous carbon.

Transforming Red Phosphorus Photocatalysis: Dual Roles of Pre-Anchored Ru Single Atoms in Defect and Interface Engineering.

Crystalline red phosphorus(CRP), known for its promising photocatalytic properties, faces challenges in photocatalytic hydrogen evolution(PHE) due to undesired inherent charge deep trapping and recombination effects induced by defects. This study overcomes these limitations through an innovative strategy in integrating ruthenium single atoms(Ru1) within CRP to simultaneously repair the intrinsic undesired vacancy defects and serve as the uniformly distributed anchoring sites for a controllable growth into ruthenium nanoparticles(RuNP). Hence, a highly functionalized CRP with Ru1 and RuNP(Ru1-NP/CRP) with concerted effects in regulating electronic structures and promoting interfacial charge transfer has been achieved. Advanced characterizations unveil the pioneering dual role of pre-anchored Ru1in transforming CRP photocatalysis. The regulations of vacancy defects on the surface of CRP minimize the detrimental deep charge trapping, resulting in the prolonged lifetime of charges. With the well-distributed in-situ growth of RuNP on Ru1 sites, the constructed robust "bridge" that connects CRP and RuNP facilitates constructive interfacial charge transfer. Ultimately, the synergistic effect induced by the pre-anchored Ru1 endows Ru1-NP/CRP with an exceptional PHE rate of 3175μmolh-1g-1, positioning it as one of the most efficient elemental-based photocatalysts. This breakthrough underscores the crucial role of pre-anchoring metal single atoms at defect sites of catalysts in enhancing hydrogen production.