Amino Trimethylene Phosphonic Acid Research Articles

Exploration of two novel highly efficient polymer composite materials based on 3-chloropropyltriethoxysilane-grafted waste para-aramid functionalized by organo-phosphonic acid/L-proline and their excellent adsorption performance for gold ions

Two novel highly efficient polymer composite adsorbents based on 3-chloropropyltriethoxysilane-grafted waste para-aramid (PPTA-CP-AT and PPTA-CP-L, PPTA=poly-p-phenylene terephthamide; CP = 3-chloropropyltriethoxysilane; AT=amino trimethylene phosphonic acid; L=L-proline) have been successfully prepared and characterized. The new adsorbents were synthesized by functionalizing 3-chloropropyltriethoxysilane-grafted waste para-aramid with amino trimethylene phosphonic acid and L-proline, respectively. They have been employed to adsorb gold ions from aqueous solution, and the relevant adsorption behaviors have been investigated in detail. The adsorption isotherms of PPTA-CP-AT and PPTA-CP-L were consistent with the Langmuir isotherm model, and the corresponding kinetics could be best described by the pseudo-second-order kinetic model. In particular, the adsorption capacity of PPTA-CP-L was much higher than the values reported in the literature. In addition, the effect of pH on the gold ions adsorption and the thermodynamic parameters of the adsorption procedure were assessed. The research results indicated that PPTA-CP-AT and PPTA-CP-L are two novel adsorbents with high efficiency in wastewater treatment and recovery of precious gold. In particular PPTA-CP-L, which was obtained through facile esterification synthesis at low temperature, showed an excellent adsorption performance and could be used as potentially excellent adsorbent for gold uptake.

Green synthesis of a novel P/N/S containing bio-based flame retardant and its applications in poly(lactic acid): rapid self-extinguish, anti-dripping, and excellent mechanical performance

Poly(lactic acid) (PLA), which is recognized as a potential biodegradable material, brings serious fire concern because of its flammability with heavily molten drips. In this investigation, a bio-based flame retardant named CS@ATMP@MI (CAM) consisting of chitosan (CS), amino trimethylene phosphonic acid (ATMP), and methionine (MI) was developed through a simple and environmental-friendly synthesis approach. CAM provided effective flame retardancy and anti-dripping ability without compromising mechanical properties. PLA/CAM composites achieved a UL-94 V-0 rating with 1.0 wt% CAM and a limited oxygen index value of 28.4 % with 3.0 wt% CAM. The high efficiency is due to the high phosphate content in ATMP and the strong coordination between CS, ATMP, and MI. The cone calorimetry tests showed that adding 2.0 wt% CAM increased the total smoke production from 0.2 to 0.6 m2, and thermogravimetric analysis/infrared spectrum analysis indicated that combustible gas production was reduced over 50 % with 3.0 wt% CAM, demonstrating that phosphorus-nitrogen synergy in CAM could effectively capture free radicals and released inert gases. Char analysis showed that the PLA/CAM composites could form a thicker and denser char layer during combustion due to phosphorus-sulfur synergy, which promoted char formation to shield mass transfer. PLA/CAM composites maintained excellent mechanical performance, with a 3.0 wt% CAM increasing tensile strength from 53.9 to 57.3 MPa and Young's modulus from 1782 to 2262 MPa. This study presented a sustainable method for synthesizing an effective bio-based flame retardant and a strategy for producing eco-friendly, fire-resistant PLA composites for industrial applications.

Effects of organic compounds rich in phosphate functional groups as multifunctional inhibitors on copper film chemical-mechanical polishing properties: Combined experiment and theoretical calculation

For copper (Cu) interconnection chemical mechanical polishing (CMP) process, the Cu film slurry follows the principles of high efficiency, environmentally friendly and low cost. In this study, hydroxyethylene diphosphonic acid (HEDP), amino-trimethylene phosphonic acid (ATMP) and ethylenediamine etramethylenephosphonic acid (EDTMP) were used as green inhibitors to study the effects of organic compounds rich in two, three and four phosphate functional groups on the corrosion inhibition properties of Cu films. The results indicated that the Cu film material removal rate (MRR) of HEDP reaches 5879 A/min and the surface roughness (Sq) is 0.85 nm, superior to the other two inhibitors. Through mechanical action analysis, electrochemical experiment, UV-Visible, X-ray photoelectron spectroscopy (XPS) test analysis and theoretical calculation, it was observed that three inhibitors could not only form stable complexes with Cu, which have the effect of corrosion inhibition, but also play a lubricating role of surfactant, and simplify the composition of slurry, and the inhibition efficiency order of them is HEDP > ATMP > EDTMP.

Developing boiling water resistant lactose-based adhesive and branched P-N synergistic flame retardant coating

In this work, lactose-based adhesive with excellent boiling water resistance was prepared by the Maillard reaction, free radical polymerisation and multiple cross-linking network strategy using lactose and biomass polyamino compound (MP) as raw materials. On the other hand, the branched P-N synergistic flame retardant coating was constructed using the developed MP reacted with aminotrimethylene phosphonic acid (ATMP), which was used to coat the surface layer of laminated composite to give it flame-retardant properties. The dry shear strength, 3 h hot water (63 °C) wet shear strength, and 3 h boiling water wet shear strength of the laminated composite were 2.23 MPa, 1.14 MPa, and 1.02 Mpa, respectively, which were in line with the requirements of GB/T 9846-2015 standard (≥0.7 MPa). In summary, this work provides potential methods for the preparation of environmentally friendly boiling water resistant lactose-based adhesive and branched P-N synergistic flame retardant coating which were used for the construction of high performance wood laminated composites.

Green synthesis of a P/N/B-containing aggregate for boosting fire-retardancy of PA6/aluminum diethylphosphinate composites

The intrinsic flammability of polyamide 6 (PA6) has significantly impeded its broad application regardless of its balanced physical properties. Aluminum diethylphosphinate (ADP), as a P-containing fire retardant, has been demonstrated to be effective in reducing flammability of PA6 because of its dual-phase modes of action by creating an intact protective char layer and inhibiting the burning process. However, the efficiency of ADP needs to be further improved for creating cost-effective fire-retardant PA6, in addition to its relatively high cost. To boost its efficiency, we, here, report a P/N/B-containing aggregate (MBA) as an effective synergist via green self-assembly of melamine (MA), boric acid (BA) and amino trimethylene phosphonic acid (ATMP) in an aqueous medium. The results show that the inclusion of 5 wt% MBA and 10 wt% ADP leads to a significantly reduced peak heat release rate (PHRR) by 52.5% compared to neat PA6, in addition to a desired UL-94 V-0 rating. A synergistic effect of 55.4 % is observed between MBA and ADP in terms of the PHRR value. This work provides a facile green strategy for developing eco-friendly multiple elements-containing fire retardants, which can be used as fire retardants alone or high-efficiency synergists for other fire retardants.

Synthesis and Performance Evaluation of Modified Polyaspartic-Acid-Based Scale Inhibitor

This paper focuses on the selection and application of scale inhibitor by studying the problem of pipeline scaling in geothermal well development. Adding scale inhibitor can effectively reduce the treatment cost and achieve a good scale resistance effect, but the commonly used polyaspartic acid scale inhibitor has problems such as poor scale inhibition effect and large use limitations. Therefore, a new modified polyaspartic acid scale inhibitor (His-Tyr-SA-PASP) was prepared using polysuccinimide (PSI) as the raw material and histidine (His), tyrosine (Tyr), and sulfonic acid (SA) as the modification reagent. When the dosage of His-Tyr-SA-PASP was 8 mg/L, the scale inhibition rate of CaCO3 was 94.40%. In addition, the scale inhibition effect of His-Tyr-SA-PASP on CaCO3 was better than that of PASP. At the same time, under the condition of a static experiment at 75 °C, according to the ion concentration of water samples in different scale zones, this paper also identified the ratio of four composite scale inhibitors. When the dosage of compound scale inhibitor was 100 mg/L, Sodium of Polyaspartic Acid–Diethylene Triamine Penta (Methylene Phosphonic Acid)–2-Phosphonobutane-1,2,4-Tricarboxylic Acid–Amino Trimethylene Phosphonic Acid–Copolymer of Maleic and Acrylic Acid = (10:10:5:1:9), (15:10:5:2.5:2.5), (12.5:5:10:1:6.5), and (15:5:10:4:1) and the scale inhibition rate was more than 95%. Under the condition of a dynamic experiment, the optimized composite scale inhibitor still showed a scale inhibition rate of more than 90%. It provides a useful reference for the practical application of water treatment in geothermal wells and has the prospect of industrial application.

Study on expanding flotation performance differentiation of quartz and magnesite by amino-trimethylphosphonic acid in dodecylamine system

In this paper, amino trimethylene phosphonic acid (ATMP) was introduced into the separation process of magnesite and quartz, in order to reduce the content of associated minerals in magnesite and improve the industrial utilization value of magnesite. Micro-flotation tests showed that under the system of dodecylamine as collector, ATMP can selectively depress magnesite within the alkaline pulp environment. When the dosage of ATMP was 100 mg/L and the pulp pH was 11, the flotation recovery of magnesite was 12.65 % and that of quartz was 91.00 %. Additionally, the findings of the artificial mixed mineral flotation showed that a concentrate with a grade of 43.53 % MgO and a recovery of 91.03 % was achieved. Zeta potential, FTIR and XPS analyses demonstrated that ATMP chelated with the active site Mg2+ on the surface of magnesite through –PO3 group. In addition, DFT calculation indicated that the adsorbed ATMP increased the distance of N atom in dodecylamine (DDA) to the surface of magnesite from 2.671 Å to 5.106 Å. The interaction energy between DDA and magnesite increased from −201.28 kJ/mol to −136.75 kJ/mol, resulting in it difficult for DDA to adsorb on the magnesite surface. However, ATMP was difficult to adsorb on the quartz surface and had no effect on the interaction between DDA and quartz. Therefore, the selective depression effect of ATMP on magnesite was realized.

Electrochemical oxidation of ATMP (Amino Trimethylene Phosphonic Acid) in low-concentrated acidic electrolyte on graphite and glassy carbon electrodes using cyclic voltammetry

This study investigates the irreversible electrochemical oxidation of Amino Trimethylene Phosphonic Acid (ATMP) in ClO4−–electrolyte on original unmodified graphite electrodes (GRE) and glassy carbon electrodes (GCE) using cyclic voltammetry (CV) as the main analytical technique. The oxidation reaction starts at ≈ +0.7 V on GRE and ≈ +0.92 V on GCE vs. Ag/AgCl (3M KCl) respectively. Four distinct electrode/electrolyte systems were selected for a comprehensive analysis of charge transfer and mass transport processes at non-Faradaic and Faradaic current regions at various scan rates υ (SR). These systems comprised of GRE/ClO4−–electrolyte, GRE/ATMP–ClO4−–electrolyte, GCE/ClO4−–electrolyte, and GCE/ATMP–ClO4−–electrolyte. Charging currents in the so-called double-layer region of the CV are found to scale linearly with SR on GCE (Adsorption mechanism); instead, the charging currents obey a nearly square root law on GRE (Diffusion mechanism). The electrochemical oxidation kinetics of ATMP in ClO4−–electrolyte using GRE and GCE obey nearly the fourth root law of the maximum oxidation current density (at the upper reverse potential) vs. SR. Finally, we identified the major transformation products generated from the ATMP electrochemical oxidation: ortho-phosphate (o− PO4), iminodimethylphosphonic acid (IDMP), and aminomethylphosphonic acid (AMPA).

Facile Fabrication of Highly Efficient Chitosan-Based Multifunctional Coating for Cotton Fabrics with Excellent Flame-Retardant and Antibacterial Properties.

Interest in the development of eco-friendly, sustainable, and convenient bio-based coatings to enhance flame retardancy and antibacterial properties in cotton fabrics is growing. In this work, chitosan was protonated at its amino groups using a method with a high atom economy using an equimolar amount of amino trimethylene phosphonic acid (ATMP), resulting in the fabrication of a single-component chitosan-based multifunctional coating (ATMP-CS), thereby avoiding any additional neutralization or purification steps. Cotton fabrics coated with various loads of ATMP-CS were prepared through a padding-drying-curing process. The morphology, thermal stability, mechanical properties, antibacterial properties, flame-retardant behavior, and flame-retardant mechanism of these fabrics were investigated. The coating exhibited excellent film-forming properties, and it imparted a uniform protective layer onto the surfaces of the cotton fabrics. When the load capacity reached 11.5%, the coated fabrics achieved a limiting oxygen index of 29.7% and successfully passed the VFT test. Moreover, the ATMP-CS coating demonstrated antibacterial rates against Escherichia coli and Staphylococcus aureus reaching 95.1% and 99.9%, respectively. This work presents a straightforward and gentle approach to fabricating colorless, environmentally friendly, and highly efficient fabric coatings that have potential applications in promoting the use of bio-based materials.

Construction of functional epoxy resin coatings based on acid-doping polyaniline coated APP: Preparation, characterization and properties

Waterborne epoxy resin (WER) coatings have attracted more and more attention because of their excellent physical and chemical properties, however, WER's flammability and high insulation limit its application. In this paper, polyaniline (PANI) doped with four different acids (sulfuric acid, phosphoric acid, citric acid and amino trimethylene phosphonic acid) was used as the shell material to coat ammonium polyphosphate (APP), and a series of multifunctional WER fillers (PANIacids/APP) integrating flame retardant, smoke suppression and antistatic properties were prepared. Then, the PANIacids/APP was compounded with WER to prepare a functional WER coating. The structures and morphologies of the PANIacids/APP fillers were characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), the results showed that acids doping could promote the formation of polyaniline coating on the surface of APP, and the PANIacids/APP filler doped by amino trimethylene phosphonic acid (ATMP) exhibits the best coating effect. Furthermore, the effects of PANIacids/APP fillers on the flame retardant property, smoke suppression property, electrical property and adhesion property of waterborne epoxy resins were explored. The results indicated that the carbon residue of WER coatings with PANIacids/APP fillers at 800 °C could reach 24.1 %-29.6 %, among which ATMP doping group has a residual carbon of 27.3 %. Also, the WER coating containing PANIATMP/APP filler possesses the best comprehensive performance, the coating has a limiting oxygen index of 31.7 % and passed V-0 level in the vertical burning test (UL-94). Compared with pure EP coating, the peak heat release rate of the PANIATMP/APP modified coating decreased by 78.1 % and the total heat release decreased by 37.8 %. Additionally, the surface resistance and adhesive force of the PANIATMP/APP modified coating reached 3.14×106 Ω and 11.8 MPa, respectively, which could meet the usage needs of anti-static application of the WER coatings.

Multifunctional flame-retardant cotton fabric with hydrophobicity and electrical conductivity for wearable smart textile and self-powered fire-alarm system

The domain of smart textiles represents a widely researched area, showcasing promising prospects. Herein, a multifunctional smart textile (CF@PM-AA) has been designed and fabricated, amalgamating flame retardancy, electrical conductivity, and hydrophobicity into a unified entity. The flame retardant, synthesized through the reaction between amino trimethylene phosphonic acid and allantoin, was impregnated into cotton fabric through a facile impregnation method. Through surface modification with polydimethylsiloxane and multi-walled carbon nanotubes, the obtained CF@PM-AA acquires exceptional hydrophobic and acid-base environment durability. Significantly, the electrical conductivity of CF@PM-AA is greatly enhanced, with a reduced resistance down from 15.9 GΩ to 13 MΩ. Based on their electrical characteristics, the copper sheet and CF@PM-AA function as the electrode and friction layers, respectively, in the construction of the triboelectric nanogenerator. This configuration produces a voltage output of up to 125.6 V at a frequency of 4 Hz. Given its outstanding flame retardancy, hydrophobicity, and electrical performance, CF@PM-AA can be integrated into firefighting suits to establish a fire-alarm system with remote signal transmission function, enhancing personnel safety. Simultaneously, the CF@PM-AA holds promise for diverse applications in wearable flame-retardant and fire-alarm systems, opening new avenues for smart textile utilization in the Internet of Things domain.

Insight into hydration inhibition mechanism of amino trimethylene phosphonic acid on tricalcium silicate from first‐principles calculations

AbstractAlthough amino trimethylene phosphoric acid (ATMP) has been widely used as a retarder for Portland cement, its effect on cement hydration is poorly understood at the atomic level. In this study, we combine static calculation and ab initio molecular dynamics (AIMD) simulation to reveal the mechanism of the effect of ATMP on the initial stage of C3S hydration from multiple perspectives, quantitatively analyze the structural reconstruction and charge migration at the ATMP/C3S interface in the aqueous environment. By adsorbing on the surface of C3S, ATMP occupies the adsorption site of water molecules. Compared with the pure C3S surface, the addition of ATMP delays the hydroxylation of the C3S surface and inhibits the formation of Ca‐Ow bonds. This work gives new insights into understanding the hydration of C3S with ATMP and offers new approach of designing new cement retarder at the molecular level.

<i>Hofmeister</i> effect regulated gel iontronic sensors for wide-range pressure perception

<p>Flexible pressure sensors, vital for medical, human-machine interaction, and intelligent recognition applications due to their high-sensitivity, excellent-linearity, and broad-pressure response, face challenges in achieving a harmonious balance among these attributes. Inspired by the gradient modulus in human skin layers, we proposed a pioneering method to adjust the gradient elastic modulus of amino trimethylene phosphonic acid (ATMP)-assisted polyvinyl alcohol (PVA) hydrogel through the <i>Hofmeister</i> effect, introducing micro-pyramid electrodes. This innovative approach successfully constructs a bio-gradient gel iontronic sensor (BGGITS) with an ultra-wide-range perception. The BGGITS exhibits a linear high-sensitivity of 700 kPa<sup>-1</sup> within a broad-pressure detection range of up to 800 kPa. The composite design, integrating gradient gel and microstructure electrodes, demonstrates exceptional pressure resolution and mechanical stability. This biomimetic skin pressure sensor holds promise for achieving linear high-sensitivity across a broader pressure range simultaneously and may find applications in electronic skin for health monitoring and tactile perception in the future.</p>

Bio-based chitosan/amino trimethylene phosphonic acid films enabling highly-efficient intumescent flame retardancy and ultra-fast fire early-warning function

Early fire warning holds immense potential for achieving more efficient fire-safety management. Despite the emergence of numerous fire-alarm sensors in recent years, they display deficiencies in providing prompt and repeatable early detection during fire accidents, thus failing to mitigate potential losses. Herein, we demonstrated a bio-based fire-warning film with chitosan (CS) and amino trimethylene phosphonic acid (ATMP) prepared by an environmental-friendly water evaporation method. The transparency, thermal stability, flame retardancy and fire-warning performances of CS and CS-ATMP films were comprehensively investigated. Remarkably, the inclusion of ATMP results in a significant improvement in the thermal stability and char yield. Moreover, the total heat release value of CS-ATMP-1 film exhibits a remarkable 35.7% reduction compared to that of pure CS film, demonstrating a substantial enhancement in flame retardancy. The thermosensitive properties of CS endow it with fire-warning capabilities. The CS-ATMP-2 film triggers an alarm signal within 0.3 s and the signal maintains for 196.0 s under alcohol flame attack, indicating its high sensitivity and stable alarm signal. Furthermore, the possible flame-retardant and fire-alarm mechanisms are proposed. This bio-based CS-ATMP film with excellent flame-retardant and repeatable early warning capacities manifests promising applications in building fire prevention and detection.

Polyaniline-doped sawdust as a promising adsorbent for defluoridation

Fluoride’s presence in groundwater is a growing concern, especially where access to safe drinking water is limited. Traditional water treatment methods have limitations in effectively removing fluoride. Thus, there is a need for an alternative, sustainable and cost-effective solution. This study develops an adsorbent where a conducting polymer (PAni) will be coated on agricultural byproduct (sawdust) for defluoridation application. Introduction of amino-tris-methylene-phosphonic acid (ATMPA) as a dopant into PAni enhances its exchange mechanism, thereby increasing its uptake capacity (58 mg/g). Potential application of this adsorbent lies in water treatment plants, which will cater needs of industry, mankind and agriculture.

Strong synergistic effects between P/N-containing supramolecular microplates and aluminum diethylphosphinate for fire-retardant PA6

Mechanically strong polyamide 6 (PA6) is an important engineering plastic, but its inherent flammability usually causes fire hazards. Aluminum diethylphosphinate (ADP) can reduce the flammability of PA6 yet fails to effectively suppress the heat release. Herein, we report a phosphorus/nitrogen (P/N)-containing supramolecular microplate (MTP) synthesized by an aqueous reaction between melamine and amino trimethylene phosphonic acid (ATMP). Combining 5 wt% MTP and 15 wt% ADP, the resulting PA6 exhibits a 67 % reduction in peak heat release rate (PHRR) and a 29 s delay in ignition time compared with those of pure PA6, as well as a UL-94 V-0 rating and a high limiting oxygen index (LOI) of 28.3 %. The barrier effect of the char in the condensed phase is mainly responsible for such high fire safety. This work provides a green approach to synthesizing strong P/N-based synergists for ADP, allowing the creation of high-performance fire-retardant PA6.

Depression mechanism of novel organic phosphoryl depressants on calcite: DFT and coordination studies

Calcite, a commonly encountered gangue mineral, is often found associated with precious metal minerals. The separation of calcite from metallic minerals is typically achieved through flotation, necessitating the development of efficient and targeted calcite depressants. This study focuses on investigating the depressant effects of three novel calcite depressants containing phosphoryl groups, namely aminotrimethylene phosphonic acid (ATMP), tetrasodium (HEDP), and diethylenetriaminepentakis (DTPMPA), through micro-flotation experiments. The obtained flotation results demonstrated the successful depression of calcite by all three reagents, with DTPMPA exhibiting the most pronounced depressing effect. Moreover, density functional theory (DFT) analysis revealed that DTPMPA possessed superior depressant capabilities on the calcite surface compared to the other two novel depressants. Coordination studies further elucidated that phosphoryl groups can form stable 6-coordination structures with calcium atoms on the calcite surface, with the coordination ability being influenced by the molecular properties of the reagents. These findings hold significant implications for achieving an efficient separation of calcite from metallic minerals, emphasizing the importance of developing high-efficiency and targeted calcite depressants.

Autogenously self-healable cementitious composite incorporating autolytic mineral microspheres: Hydration regulation and structural alteration

This work proposes a novel insight into the autolytic mineral self-healing strategies for cementitious materials. The autolytic mineral microsphere (AMM) was prepared via the fluidization technique with cement clinker/calcium oxide as the healing substances and amino trimethylene phosphonic acid as the autolytic coating film. The basic characteristics of AMM and its hydration influence on the cementitious composite were analyzed by the laser particle analyzer, calorimetry, X-ray diffractometry and scanning electron microscopy. The autogenous self-healing capacity of the cementitious composite incorporating AMM was assessed by the crack closure, flexural property restoration and electrochemical impedance spectroscopy. Through the autolytic procedure, AMM regulated the hydration evolution and enhanced the self-healing performance of cementitious composite. The AMM containing cement clinker steadily healed the crack, leading to a well regeneration of fractured structure and restoration of flexural property. The partial substitution of cement clinker by calcium oxide in AMM further increased the crack filling, but induced a volume instability of the cement matrix as well, resulting in the strength decrease under a long-term secondary hydration. The structural alteration of cementitious composite was predominately impacted by the self-healing effect in the first 28 d re-curing, whilst the volume instability effect played a dominant role subsequently.

Touchable Gustation via a Hoffmeister Gel Iontronic Sensor

A particular sense, touchable gustation, was achieved. We proposed a chemical-mechanical interface strategy with an iontronic sensor device. A conductive hydrogel, amino trimethylene phosphonic acid (ATMP) assisted poly(vinyl alcohol) (PVA), was employed as the dielectric layer of the gel iontronic sensor. The Hofmeister effect of the ATMP-PVA hydrogel was well investigated to establish the quantitative description of the gel elasticity modulus to chemical cosolvents. The mechanical properties of hydrogels can be transduced extensively and reversibly by regulating the aggregation state of polymer chains with hydrated ions or cosolvents. Scanning electron microscopy (SEM) images of ATMP-PVA hydrogel microstructures stained with different soaked cosolvents present different networks. The information on different chemical components will be stored in the ATMP-PVA gels. The flexible gel iontronic sensor with a hierarchical pyramid structure performed high linear sensitivity of 3224.2 kPa-1 and wide pressure response in the range of 0-100 kPa. The finite element analysis proved the pressure distribution at the gel interface of the gel iontronic sensor and the capacitation-stress response relation. Various cations, anions, amino acids, and saccharides can be discriminated, classified, and quantified with the gel iontronic sensor. The Hofmeister effect regulated chemical-mechanical interface performs the response and conversion of biological/chemical signals into electrical output in real time. The particular function to tactile with gustation percept will contribute promising applications in the human-machine interaction, humanoid robot, clinic treatment, or athletic training optimization.

FeP nanoparticles highly dispersed on N,P-doped petaloid carbon nanosheet: Interface engineering and boosted intrinsic ORR activity

Modulating the surface structure and intrinsic activity of iron phosphides (FeP) is of great importance to improve their oxygen reduction reaction (ORR) activity. In this work, aminotrimethylene phosphonic acid (ATMP) and melamine (MA) were introduced as acid and base ligand respectively to fabricate hydrogen-bonded organic frameworks (HOF)-like precursor (ATMP-MA). After high-temperature treatment, the obtained FeP supported on 3D nitrogen (N) and phosphorus (P)-doped petaloid carbon nanosheet (FeP/NPC) displayed the desired improved ORR performance. An improved onset potential (0.922 V vs. RHE) and diffusion limiting current (5.480 mA cm−2) could be realized, superior to those of Pt/C (0.911 V, 5.380 mA cm−2). Moreover, ultraviolet photoemission spectroscopycharacterization consistently revealed that the proper P and N doping could effectively regulate the electronic structure, promote electron transport, and lower the d-band center position of Fe. This work may streamline the strategy of transition metal phosphides with enhanced reactive activity for ORR.