Phosphorus Doping Research Articles

Unlocking High-Current Performance in Silicon Anode: Synergistic Phosphorus Doping and Nitrogen-Doped Carbon Encapsulation to Enhance Lithium Diffusivity.

The silicon (Si) offers enormous theoretical capacity as a lithium-ion battery (LIB) anode. However, the low charge mobility in Si particles hinders its application for high current loading. In this study, ball-milled phosphorus-doped Si nanoparticles encapsulated with nitrogen-doped carbon (P-Si@N-C) are employed as an anode for LIBs. P-doped Si nanoparticles are first obtained via ball-milling and calcination of Si with phosphoric acid. N-doped carbon encapsulation is then introduced via carbonization of the surfactant-assisted polymerization of pyrrole monomer on P-doped Si. While P dopant is required to support the stability at high current density, the encapsulation of Si particles with N-doped carbon is influential in enhancing the overall Li+ diffusivity of the Si anode. The combined approaches improve the anode's Li+ diffusivity up to tenfold compared to the untreated anode. It leads to exceptional anode stability at a high current, retaining 87 % of its initial capacity under a large current rate of 4000 mA g-1. The full-cell comprising P-Si@N-C anode and LiFePO4 cathode demonstrates 94 % capacity retention of its initial capacity after 100 cycles at 1 C. This study explores the effective strategies to improve Li+ diffusivity for high-rate Si-based anode.

Achieving the optimal performance of VO@CoNC anchored on MX/CF through phosphorous-doped induced defects for the fiber-shaped solid-state Zn-ion battery

Aqueous zinc-ion batteries (ZIBs) are instrumental in advancing sustainable energy storage technologies, primarily due to their affordability and eco-friendliness. However, their further development into fiber-shaped ZIBs (FSZIBs) has been impeded by challenges related to appropriate 1D cathode materials coupled with low conductivity, sluggish kinetics, structural instability, low mass loading, inefficient ion pathways, and lack of flexibility. Herein, an integrated hybrid fiber-shaped cathode electrode (Px–V2O5–x@CoNC@MX/CF) for the FSZIB is developed. The reported electrode design incorporates bimetallic metal–organic framework (MOF)-derived leaf-like CoNC structures, providing active sites and conductive connections for vanadium oxide-based nanofibril structure and the porous MXene-carbon fiber (MX/CF) substrate. Tuning the electronic structure, through phosphorus doping and creating oxygen vacancies, provides the resulting Px–V2O5–x@CoNC@MX/CF electrode with good Zn2+ diffusion ability and stabilizes the vanadium oxide structure, to exhibit exceptional electrochemical performance as cathode for FSZIB. This strategy simultaneously enhances active material growth, prevents structural degradation, and facilitates a highly reversible de/intercalation process of Zn2+ ions. The assembled fiber-shaped solid-state ZIB (FSSZIB) based on Px–V2O5–x@CoNC@MX/CF as the cathode and ZnNS@MX/CF as the anode demonstrates high energy density of 133 mWh/cm3 and power density of 425.2 mW/cm3. Moreover, the FSSZIB exhibits excellent cycling stability, with capacity retention of 79.8 % after 20,000 charge–discharge cycles, demonstrating its long-term durability.

Bi-layer in-situ phosphorus doped poly-Si films by PECVD for blistering-free high-efficiency industrial TOPCon solar cells

The passivating contact concept stands out as one of the most promising and industrially viable photovoltaic (PV) technologies. Further improving the quality of physical contact has become a focus of ongoing research. The film blistering issue has been identified as one of the major bottlenecks for the polysilicon (poly-Si) films deposited by the PECVD approach. In this study, we investigated how the in-situ phosphorus (P) doping level within the poly-Si films contributes to the occurrence of blistering. Our investigations into the film blistering mechanisms reveal that a high in-situ P-doping suppresses hydrogen release levels and reduces the accumulation of residual stress during annealing, which leads to the blistering-free appearance, especially observed in heavily P-doped poly-Si films. However, as excessive P-doping could weaken the interfacial passivation quality, we propose a bi-layer structure of P-doped poly-Si films which allows the doping profile to be tailored and maintain good quality passivating contacts. Based on the bi-layer structure, we fabricated industrial-sized tunnel oxide passivated contact (TOPCon) solar cells, which attained an average efficiency of 23.84%. Our work not only presents a promising strategy for improving the performance of passivating contacts via the PECVD approach but also underscores the significant potential for its widespread implementation in industrial TOPCon solar cell manufacturing.

Effective chromium mitigation using phosphorous doped bio carbon electrode via capacitive deionisation

ABSTRACT Capacitive deionisation (CDI) is an emerging eco-economic water reclamation technology that can remove inorganic salts and heavy metals. Biomass-derived carbon electrodes have attracted the scientific communities in recent years due to their economic feasibility and sustainability. However, electrochemical performance needs to be improved to achieve durability and reusability. Hence, the present study develops rice straw-derived phosphorous-doped (P-doped) carbon as an electrode for mitigating Cr(VI) ions. Phosphorus doping of biocarbon electrodes enhances their electrochemical properties, including increased electrical conductivity, improved charge storage capacity, and enhanced ion adsorption capabilities. Here, Phosphoric acid plays a dual role of activation and doping that enhances the physico-electrochemical properties. The synthesised material was found to be P-doped carbon with better pore distribution, which was confirmed through FESEM-EDX analysis. Further, the physicochemical properties of the electrode material are enriched with carbon and possess an enhanced surface area of 753 m2/g. The cyclic voltammetry shows the specific capacitance of 67 F/g for the Cr(VI) ions, which was found to be 15 times more than the non-doped carbon. CDI studies were performed with optimisation of operational parameters and found that mitigation of Cr(VI) ions was efficient at pH 2 for the applied voltage of 2V. The electrode’s performance with real-time chrome wash effluent confirms its potentiality and has better scope upon optimisation. The experimental data fits well with pseudo first-order kinetics, which ensures the nature of electrosorption is physisorption.

Phosphorus doped magnetic biochar activated PMS for effective degradation of pesticide in water: Targeted regulation of interfacial charge transfer by phosphorus doping

In this study, the incorporation of phosphorus (P) atoms into magnetic biochar was strategically achieved, and the preparation conditions of the composites were optimized by adjusting the pyrolysis temperature and iron doping. The resulting P-doped magnetic biochar (Fe2P@BC-700) exhibited remarkable catalytic activity towards peroxymonosulfate (PMS), rendering it highly effective for the degradation of common organic pesticides, such as 2-Methyl-4-chlorophenoxyacetic acid (MCPA), in aqueous environments. Among them, the apparent rate constant in the oxidation stage was 6.42 times as large as that of magnetic biochar (Fe2BC-700). This was attributed to the fact that the introduced P species tuned the surface electronic configuration of the pristine carbon layer with excellent electron storage and transport capabilities, and the Fe-O-P bonds in the composites acted as electron transport bridges to promote iron cycling in the magnetic nanoparticles during catalysis. The elimination of MCPA in the constructed adsorption enrichment-oxidative degradation system (Fe2P@BC-700/PMS) was achieved through a non-radical pathway dominated by singlet oxygen (1O2) and electron transfer process (ETP). It also ensured broad pH adaptability, environmental stability and repeatability. Density-functional theory calculated that ROS tended to attack the C-Cl branched chain in MCPA and the degradation products showed a tendency of toxicity reduction. This study provided new ideas for the design of market-oriented functional biochar catalysts.

Atomic ordered doping leads to enhanced sensitivity of phosgene gas detection in graphene nanoribbon: a quantum DFT approach

We explore a novel sensor for detection of phosgene gas by graphene derivatives such as pristine and doped graphene nanoribbons via first principles calculations. The interaction of phosgene molecule with various edge and center doped configurations of boron, phosphorus and boron-phosphorus co-doped armchair graphene nanoribbon (AGNR) and zigzag graphene nanoribbon (ZGNR) is investigated through density functional theory (DFT). P-doped systems showcase chemisorption, displaying enhanced sensitivity to phosgene detection as reflected by a more negative adsorption energy values, accompanied by a prominent charge transfer due to the doping. Regardless of nanoribbon geometry, the binding energies of P-doped systems exhibit notable uniformity within the range of −8.01 eV to −8.49 eV, however the adsorption energies in ZGNR are significantly lower than those observed in AGNR. Due to much higher(lower) electron-donating (accepting) capacity of phosphorous(boron) atoms in comparison to ‘C’ atom, substitutional doping with ‘P’ or ‘B’ atoms in AGNR has signifiant impact on the structural, electronic and adsorption properties of the nanoribbons. We observe that phosphorus doped configurations (edge/center) effectively interact with phosgene molecule with higher adsorption that corresponds to the chemisorption phenomenon. The strongest adsorption energy (−8.83 eV) is obtained for P doped configurations, followed by that for B+P co-doped AGNR (−4.23 eV). These results suggest significantly stronger adsorption of phosgene gas on P doped AGNR than on any other systems reported so far. Band structure analysis estimates that by phosphorus doping, changes in the band gap is significant and it also shows prominent changes in the band structures. Isosurface electronic charge density plots identify that the transfer of charge takes place from graphene system to phosgene molecule. Thus, significant variation in adsorption and electronic properties of P doped AGNR reveal that these geometries immensely promote the detection of phosgene gas, and may be considered as promising chemical sensor for phosgene removal.

Oxygen vacancies enhanced electrocatalytic water splitting of P-FeMoO4 initiated via phosphorus doping

Transition metal oxides (TMOs) are abundant and cost-effective materials. However, poor conductivity and low intrinsic activity limit their application in electrolyzed water catalysts. Herein, we prepared P-FeMoO4 in situ on nickel foam (P-FMO@NF) by phosphorylation-modified FeMoO4 to optimize its electrocatalytic properties. Interestingly, phosphorus doping is accompanied by the generation of oxygen vacancies and surface phosphates. Oxygen vacancies accelerated Mo dissolution during the oxygen evolution reaction (OER), leading to the rapid reconfiguration of P-FMO@NF to FeOOH and regulating the electronic structure of P-FMO@NF. The formation of phosphates is caused by the substitution of some molybdates with phosphates, which further increases the amount of oxygen vacancies. Hence, the OER overpotential of P-FMO@NF at a current density of 10 mA cm−2 is only 206 mV, and the hydrogen evolution reaction (HER) overpotential is 154 mV. It was assembled into a water splitting cell with a voltage of just 1.59 V at 10 mA cm−2 and shows excellent stability over 50 h. These excellent electrocatalytic properties are mainly attributed to the oxygen vacancies, which improve the interfacial charge transfer properties of the catalysts. This study provides new insights into phosphorus doping and offers a new perspective on the design of electrocatalysts.

Boosting the electrochromic performance of P-doped WO3 films via electrodeposition for smart window applications.

Electrochromic smart windows have attracted more attention from researchers due to their potential applications for energy conservation in buildings. As the most key component, the electrochromic layer is still limited by the complexity of the preparation process and poor performance, such as lower stability, slow response time, and low coloration efficiency. In this study, as a simple and expedient method, electrodeposition is successfully used to prepare amorphous WO3 films doped with P. By optimizing the amount of P in the PW-2 film, a large optical modulation of 80.8% at 550 nm is achieved, and the P-doped amorphous WO3 film also shows a fast response time, a high CE, and good cycling stability. The mechanism of the P-doped amorphous WO3 films to improve the electrochromic properties is as follows. Firstly, by appropriate phosphorus doping, the stress of the film is released, and the binding force is improved. Secondly, the films possess proper cracks, which accelerate the diffusion of ions. Thirdly, the films make the nanoparticles more uniform, and provide more active sites. Furthermore, the electrochromic smart windows based on the P-doped amorphous WO3 film display a large temperature difference of 11 °C, which indicates good solar thermal regulation ability, and promises practical applications for building energy conservation.

Triple-chain boron clusters: lengthening via phosphorus doping and enhancing stability through {P} by {CH} substitution

This theoretical study presents novel insights into the doping of boron clusters with an increasing number of dopant atoms, ranging from 1 to 4, that preserve the integrity of the original boron framework. The B16P4 cluster has a triple-chain shape.

High conductivity characteristics of phosphorus-doped nanocrystalline silicon thin films by KrF pulsed excimer laser irradiation method.

The microstructure and high conductivity properties of phosphorus-doped nanocrystalline silicon films were investigated on samples prepared by a plasma-enhanced chemical vapor deposition technique and the KrF pulsed excimer laser irradiation method. The results of Fourier transform infrared spectroscopy and Raman spectroscopy show that Si nanocrystallites with an average diameter of 2 nm to 3 nm are formed in the film. The degree of crystallinity increases with the increase of laser radiation intensity, while the content of hydrogen decreases gradually. More phosphorus atoms are substitutionally incorporated into the nc-Si dots under higher laser irradiation fluence, which is responsible for the high dark conductivity. By controlling the laser fluence at 1.0 J cm-2, the dark conductivity as high as 25.7 S cm-1 can be obtained. Based on the measurements of temperature-dependent conductivity, the carrier transport processes are discussed. The phosphorus doping and the increase of electron concentration are considered to be the reason for high dark conductivity and extremely low conductivity activation energy.

Al, P-co-doping and interface engineering synergistically boost the electrocatalytic performance of WS2/Ni3S2/NiS nanosheet heterostructure for efficient hydrogen evolution reaction.

The fabrication of earth-abundant electrocatalysts capable of facilitating hydrogen evolution reactions (HER) is essential for creating sustainable hydrogen fuel by water splitting. Here, we present a one-pot hydrothermal approach for producing aluminum and phosphorus co-doped NiS/Ni3S2/WS2 heterostructure hybrid frameworks on nickel foam. The optimal Al and Al, P/NiWS-b@NF catalyst exhibits high HER activity with overpotentials of 139 and 227 mV at current densities of 10 and 50 mA cm-2, respectively, thanks to the synergistic effect of the various constituents of the catalyst. What is more, it also exhibits a promising Tafel slope of 124 mV dec-1 and is electrocatalytically durable for 10 hours in 0.5 M H2SO4 solution. The high HER activity of Al, P/NiWS-b@NF could be explained by the large number of active sites of the hierarchical heterostructure and electron effects produced by the combination of interfacial and aluminum and phosphorus doping.

Simulation-Driven Fabrication and Performance Evaluation of n-MOSFET using Silvaco Athena and Atlas: From Process to Parameters

In this work, an n-channel MOSFET of Silvaco TCAD has been fabricated and analyzed using commercially available simulation software tools, namely Athena and Atlas. The fabrication of NMOS has been done through a series of fabrication steps, which include wafer selection with appropriate orientation and phosphorus doping, oxide diffusion, boron-implantation for p-well formation, polysilicon deposition, phosphorus-implantation for heavily doped n+-regions, aluminum-deposition for source/drain contact and extraction of unused materials- all of these steps has been performed through the Athena tool. Afterward, Atlas performs several simulations to deduce the transfer characteristics curves (the ID vs. VGS curves). The various performance parameters of the fabricated device, which include the on current (Ion), the off current (Ioff), the on/off ratio, the threshold voltage (Vth), the subthreshold swing, and the Drain-Induced Barrier Lowering (DIBL), are also determined using the Atlas tool. These simulation-based analyses provide a better understanding of an NMOS device's fabrication process and a clearer physical insight into its characteristic curves and performance parameters.

Microwave-assisted synthesis and characterization of SrAl2O4/Eu/Dy and the role of phosphorus dopants on its fluorescence and phosphorescence properties

Microwave-assisted synthesis and characterization of SrAl2O4/Eu/Dy and the role of phosphorus dopants on its fluorescence and phosphorescence properties

Phosphorus doping of nickel–cobalt boride to produce a metal–metalloid–nonmetal electrocatalyst for improved overall water splitting

A phosphorus-doped nickel–cobalt boride (P-NCB) electrocatalyst designed based on a unique metal–metalloid–nonmetal configuration results in solitary structures with excellent bifunctional properties for the HER and OER under strongly alkaline conditions.

Microwave-assisted exploration of the electron configuration-dependent electrocatalytic urea oxidation activity of 2D porous NiCo2O4 spinel

Urea holds promise as an alternative water-oxidation substrate in electrolytic cells. High-valence nickel-based spinel, especially after heteroatom doping, excels in urea oxidation reactions (UOR). However, traditional spinel synthesis methods with prolonged high-temperature reactions lack kinetic precision, hindering the balance between controlled doping and highly active two-dimensional (2D) porous structures design. This significantly impedes the identification of electron configuration-dependent active sites in doped 2D nickel-based spinels. Herein, we present a microwave shock method for the preparation of 2D porous NiCo2O4 spinel. Utilizing the transient on-off property of microwave pulses for precise heteroatom doping and 2D porous structural design, non-metal doping (boron, phosphorus, and sulfur) with distinct extranuclear electron disparities serves as straightforward examples for investigation. Precise tuning of lattice parameter reveals the impact of covalent bond strength on NiCo2O4 structural stability. The introduced defect levels induce unpaired d-electrons in transition metals, enhancing the adsorption of electron-donating amino groups in urea molecules. Simultaneously, Bode plots confirm the impact mechanism of rapid electron migration caused by reduced band gaps on UOR activity. The prepared phosphorus-doped 2D porous NiCo2O4, with optimal electron configuration control, outperforms most reported spinels. This controlled modification strategy advances understanding theoretical structure-activity mechanisms of high-performance 2D spinels in UOR.

Synthesis of sewage sludge biochar in molten salt environment for advanced wastewater treatment: Performance enhancement, carbon footprint and environmental impact reduction

Sewage sludge (SS) pyrolysis to produce biochar is a vital approach for treating and utilizing SS, while reducing the carbon footprint of SS disposal. However, the high inorganic content in SS results in low carbon content and underdeveloped pore structure of biochar prepared under inert atmospheres. There is a significant risk of secondary pollutant emissions, including CO2, SO2, and NOx. In this study, we propose an innovative approach that utilizes excess molten salts, specifically a Li-Na-K molten carbonate (MC) and a Li-Na-K molten chloride (MCH), to create a medium-temperature liquid phase reaction environment (500 °C) for SS pyrolysis. This environment promotes the functional enhancement of biochar (SSB-MC and SSB-MCH) and in-situ absorption of secondary pollutants. The pore structure of SSB-MC and SSB-MCH are greatly optimized. Thanks to the dissolution of calcium-silicon-aluminum-based minerals by molten salt, the carbon content is also significantly increased. The increased specific surface area and surface-enriched functional groups (O, N, P, etc.) of SSB-MC result in greatly enhanced adsorption performance for Rhodamine B (27.9 to 89.1 mg g−1). SSB-MCH, due to the increased iron and phosphorus doping, also exhibits enhanced Fenton oxidation capability. Life cycle assessments demonstrate that the molten salt processes effectively reduce the carbon footprint, energy consumption, and environmental impact.

Highly Hydrophilic and Defective Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution.

Graphitic carbon nitride (g-C3N4), as a kind of nonmetallic low-cost photocatalyst, has great potential in photocatalytic hydrogen (H2) evolution, but its poor hydrophilicity and nonwetting extremely limit its H2 evolution efficiency. Herein, highly hydrophilic and defective g-C3N4 photocatalysts (NH3-CN-P as a representative example) have been fabricated on the basis of the strategy of joint phosphorus doping and ammonia stripping. The dopant of phosphorus prefers to occupy the C atoms bonded to -NH2 groups in the g-C3N4 skeleton, which is conducive to the formation of N defects caused by the effects of electronegativity and charge balance. Moreover, ammonia stripping plays a dual role in exposing plentiful two-dimensional defective planar structure and implanting the hydrophilic groups on the surface. As expected, the photocatalytic H2 evolution property of NH3-CN-P reaches 11.31 mmol g-1 h-1, with an apparent quantum yield of 17.9% at 420 nm, outperforming the majority of the reported g-C3N4-based photocatalysts.

Enhancing the electrochemical performance of single-crystal LiNi0.8Co0.1Mn0.1O2 cathode material by phosphorus doping

High nickel ternary cathode materials display high specific capacity and low cost, but still suffer irreversible phase change, side reaction and particle cracking during the electrochemical reaction processes. Herein, a P-doped single crystal Ni-rich cathode material is designed, which shows excellent lithium-ion insertion/extraction capability. The phase transition (H1 → H2 → H3) is relieved by the accumulation of interfacial force due to P-doping, as which increases the charge density and promotes the electrostatic repulsion between oxygen layers. P-doping also leads to an increase of lattice parameter c, and the increased thickness of lithium layers and transition metal layers expands the two-dimensional diffusion channel of lithium-ion in the layered structure, facilitating the lithium-ion insertion/extraction processes. The doped ternary single crystal cathode material demonstrates a stable surface structure with resistance to environmental erosion. This work demonstrates that the P-doping is promising to further improve ternary single crystal cathode material for superior lithium-ion battery applications.

Copper Phosphinate Complexes as Molecular Precursors for Ethanol Dehydrogenation Catalysts.

Nowadays, the production of acetaldehyde heavily relies on the petroleum industry. Developing new catalysts for the ethanol dehydrogenation process that could sustainably substitute current acetaldehyde production methods is highly desired. Among the ethanol dehydrogenation catalysts, copper-based materials have been intensively studied. Unfortunately, the Cu-based catalysts suffer from sintering and coking, which lead to rapid deactivation with time-on-stream. Phosphorus doping has been demonstrated to diminish coking in methanol dehydrogenation, fluid catalytic cracking, and ethanol-to-olefin reactions. This work reports a pioneering application of the well-characterized copper phosphinate complexes as molecular precursors for copper-based ethanol dehydrogenation catalysts enriched with phosphate groups (Cu-phosphate/SiO2). Three new catalysts (CuP-1, CuP-2, and CuP-3), prepared by the deposition of complexes {Cu(SAAP)}n (1), [Cu6(BSAAP)6] (2), and [Cu3(NAAP)3] (3) on the surface of commercial SiO2, calcination at 500 °C, and reduction in the stream of the forming gas 5% H2/N2 at 400 °C, exhibited unusual properties. First, the catalysts showed a rapid increase in catalytic activity. After reaching the maximum conversion, the catalyst started to deactivate. The unusual behavior could be explained by the presence of the phosphate phase, which made Cu2+ reduction more difficult. The phosphorus content gradually decreased during time-on-stream, copper was reduced, and the activity increased. The deactivation of the catalyst could be related to the copper diffusion processes. The most active CuP-1 catalyst reaches a maximum of 73% ethanol conversion and over 98% acetaldehyde selectivity at 325 °C and WHSV = 2.37 h-1.

Engineering lattice oxygen defects and polaronic transport in vanadium pentoxide via isovalent phosphorus doping

Oxygen vacancies are equilibrium defects in the vanadium pentoxide system that give rise to polaronic hopping transport via V4+ charge compensating defect. In this paper, we report the tunability of polaron formation, the hopping process, and their magnetic signature by substitution of isovalent (5+) phosphorus ions in the V5+ site. The powder x-ray diffraction data show a monotonous shift in lattice parameters with progressive P-doping, confirming the presence of a substitutional dopant. The polaron hopping energy reduced from 0.307 to 0.290 eV depicting a lower defect concentration in P-doping in V2O5. At low temperatures, it is found to obey the Efros–Shklovskii variable range hopping mechanism. The estimated hopping range increased to 1.6 ± 0.1 nm in doped V2O5 in contrast to ∼1.3 nm in the undoped one. The electron spin resonance measurements show a diminishing broad ferromagnetic signal and rising paramagnetic signal (g = 1.97) with progressive P-doping depicting predominant isolated electronic spins in the doped sample. The same is corroborated in room temperature M–H with a distinct hysteresis that diminishes with P-doping and a rise of a paramagnetic slope. Moreover, the reduced oxygen defects and lower V4+ relative occupancy together with fermi level fall toward intrinsic position are substantiated by photoelectron emission studies.