Ternary Doping Research Articles

Modulating Valence Electrons and Na Occupancy in Layered Cathodes for High-Performance Na-Ion Batteries.

Na-ion batteries (NIBs) hold promise as a leading option for large-scale energy storage. However, their development faces challenges due to the lack of high-performance cathode materials. P2-type layered oxides are seen as potential cathode materials for NIBs due to higher structure stability, yet their commercialization is hindered by limited capacity and subpar phase transitions during Na extraction and insertion at high voltages. In this study, we introduce a new P2-type cathode material, Na0.76Ni0.23Li0.1Ti0.02Mn0.65O1.998F0.02 (NLTMOF), synthesized with ternary Li/Ti/F substitution. This modification of ternary Li/Ti/F substitution significantly tailors the electronic structures, increasing the number of valence electrons near the Fermi energy level. This facilitates the electronic conductivity and their involvement in charge compensation, thereby enhancing reversible capacity. Additionally, ternary doping synergistically adjusts the Na occupancy at the Na layer for favorable Na extraction without P2-O2 phase transitions even under a high voltage of 4.4 V, boosting cycling stability. As a result, NLTMOF demonstrates a reversible capacity of 110.0 and 132.2 mAh g-1 at 2-4.2 and 2-4.4 V, respectively, and maintains greatly enhanced cycling stability over long cycles. This study sheds light on the design of transition metal oxides for advanced cathode materials through the modulation of electronic structure and Na occupancy in cathode materials, thus promoting the development of NIBs.

The phase-stabilized behavior of Sc2O3–Y2O3 co-doped ZrO2 nanopowders by co-precipitation synthesis

Single stabilizer-doped ZrO2 has drawbacks such as inferior mechanical properties and thermal stability, making it difficult to obtain ZrO2 ceramics with good density and high crystallinity. Thus, it is expected that ZrO2 is doped and modified by two or more stabilizers. In this paper, the Sc2O3–Y2O3–ZrO2 nanocomposite ceramic powders were prepared using ZrOCl2⋅8H2O, ScCl3⋅6H2O, and YCl3⋅6H2O as raw materials and polyvinylpyrrolidone as dispersant. They calcined at diverse temperaturesby the pressureless sintering-assisted co-precipitation method after being pressed into disc shape. Sc2O3 and Y2O3 were added as ZrO2 stabilizers to ameliorate the lack of insufficient mechanical properties and high-temperature stability of ZrO2 ceramics caused by single doping. To study the stability of the phases at high temperatures, the specimens were characterized by TG-DTG, XRD, Raman, SEM, FT-IR, etc. The effects of different pH valuesand different calcination temperatures on the Sc2O3–Y2O3–ZrO2 nanocomposite ceramics were investigated. It was demonstrated that ternary doping has very excellent phase stability. After calcination no monoclinic phase appeared, and the precursor samples were transformed from amorphous to a large amount of tetragonal phases and a few cubic phases. The samples at pH = 10 and calcination temperature of 1000 °C showed the best stabilization, the most uniform grain development, the best crystallinity, the most regular morphology, the highest tetragonal phase content of 89.2 %, the stabilization rate of 94.58 %, and the highest relative density of 98.75 %. The results show that this nanocrystalline powder can be used to prepare high-density nanoceramics. Furthermore, the activation energy for grain growth of Sc2O3–Y2O3–ZrO2 nanocomposite ceramics was calculated as 13.87 kJ/mol. This paper provides a theoretical and experimental research basis for the controlled synthesis of Sc2O3–Y2O3–ZrO2 nanocomposite ceramics using a pressureless sintering-assisted co-precipitation method.

Dynamic photo-enhanced polyacrylic acid-based room temperature phosphorescence materials with persistent long-wavelength and even near-infrared luminescence via Förster resonance energy transfer

Stimulus-responsive organic room temperature phosphorescence (RTP) materials have attracted widespread attention in chemical sensors, bioimaging and information security. In this work, a dynamic photo-enhanced RTP material is prepared by doping 1,8-naphthalic anhydride (NA) into the polyacrylic acid (PAA) matrix. After 10 min irradiation of 302 nm UV light, the RTP properties of the doping systems PAA-NA are significantly enhanced and the photo-enhanced performances show excellent reversibility. More interestingly, PAA-NA as energy donor and the commercial dye rhodamine B (RhB) as energy acceptor are used to construct the ternary doping systems PAA-NA-RhB, which exhibit color-tunable long afterglow from orange to red through the triplet-to-singlet Förster resonance energy transfer (TS-FRET) process. Significantly, RhB as the intermediate and near infrared (NIR) dye Nile blue (NiB) as energy acceptor are codoped into energy donor PAA-NA matrices to facilely prepare the quaternary doping systems PAA-NA-RhB-NiB, and persistent NIR luminescence is realized successfully via the stepwise FRET process after 10 min irradiation of 302 nm UV light. The great application potential of the prepared photo-enhanced PAA-based RTP materials in high-level information encryption has been confirmed due to their excellent RTP performance. This study broadens the range of photo-enhanced polymer-based RTP materials and extends the persistent luminescence of PAA-based RTP materials to the long-wavelength and NIR regions.

Enhancing the electrochemical and mechanical performance of LiFePO4 cathode material by ternary doping of Mn, Ti, and N

This study employs a first-principles approach based on density functional theory to analyze the electrochemical and mechanical properties of LiFePO4 system with Mn, Ti, and N ternary doping. Computational findings reveal a formation energy of −1.98 eV, affirming excellent stability. Doping generates impurity bands, reducing the bandgap to 1.21 eV and enhancing conductivity. Doping significantly improves Li-ion diffusion, increasing the coefficient by 6 orders of magnitude and reducing the energy barrier by 0.35 eV. Moreover, Ti doping induces favorable local structural changes and enhances Li-ion diffusion. Mechanical performance calculations indicate improved stability, toughness, and isotropy. Ternary doping raises de-lithiation voltage, optimizing charge–discharge curves without compromising the capacity of LiFePO4, enhancing electrochemical performance.

Surface engineering of ternary mixed transition metal oxides for highly efficient catalytic oxidation of low concentration VOCs

With the widespread application of waterborne painting process, effective removal technologies for low concentration volatile organic compounds (VOCs) is a major concern of the painting industries due to the low mass transfer efficiency. This work presents a unique approach for the molecular-level preparation of precious-metal-free mixed aliovalent-substituted, CeCuOx binary oxide and NiO-modified yNi/CeCuOx ternary mixed metal oxide catalysts. In addition, the excellent catalytic selectivity (no catalytic activity decreases under 5.0 vol% water vapor) of the catalysts was successfully achieved by microstructures optimization and grafting octadecyltrichlorosilane (OTS). Its catalytic activity in the oxidation of toluene at low concentrations (50 ppm) was studied. The 3Ni/CeCuOx sample exhibits the best performance, which achieve 90 % catalytic oxidation of toluene at 197 °C without using noble metals. This results from that the ternary doping and the growth of NiO increases the specific surface area, active lattice oxygen species, activates molecular oxygen species, and provides more catalytic sites, which improve the adsorption and catalysis of toluene. Furthermore, the catalytic stability of the catalysts is also significantly improved by the addition of the hydrophobic coating. Therefore, the unique catalysts have great potential in practical applications for low concentration VOCs removal of painting industries.

Achieving color-tunable persistent afterglow from ultralong polyacrylamide-based room-temperature phosphorescence materials through phosphorescence Förster resonance energy transfer

Polymer-based pure organic room-temperature phosphorescence (RTP) materials have received widespread attention due to their great application prospects in many fields. However, the reports about polymer-based multicolor RTP materials were still rare. Herein, a series of monochromatic PAM-based RTP materials are constructed by facilely doping boric acid derivatives into polyacrylamide (PAM) matrices. Due to the strong intermolecular hydrogen-bonding interaction, 4-carboxyphenylboronic acid (CPBA) doped system PAM/CPBA achieves an ultralong RTP lifetime of 753 ms with a naked-eye visible blue afterglow up to 12 s. Significantly, PAM/CPBA as energy donor and the commercial fluorescent dye fluorescein (FL) or rhodamine B (RhB) as energy acceptor are used to fabricated ternary doping systems to achieve multicolor afterglow emission through phosphorescence Förster resonance energy transfer (FRET). The afterglow colors of PAM/CPBA/FL and PAM/CPBA/RhB can be easily adjusted from blue to yellow or purple by changing the doping content of FL or RhB. Inspiringly, a nearly white afterglow emission from the quaternary doping system PAM/CPBA/RhB/FL is achieved by varying the amount of FL content. Furthermore, the prepared PAM-based binary and ternary doping RTP materials can be applied in the field of information encryption.

Synergistic doping with Ag, CdO, and ZnO to overcome electron-hole recombination in TiO2 photocatalysis for effective water photo splitting reaction.

This manuscript is dedicated to a comprehensive exploration of the multifaceted challenge of fast electron-hole recombination in titanium dioxide photocatalysis, with a primary focus on its critical role in advancing the field of water photo splitting. To address this challenge, three prominent approaches-Schottky barriers, Z-scheme systems, and type II heterojunctions-were rigorously investigated for their potential to ameliorate TiO2's photocatalytic performance toward water photo splitting. Three distinct dopants-silver, cadmium oxide, and zinc oxide-were strategically employed. This research also delved into the dynamic interplay between these dopants, analyzing the synergetic effects that arise from binary and tertiary doping configurations. The results concluded that incorporation of Ag, CdO, and ZnO dopants effectively countered the fast electron-hole recombination problem in TiO2 NPs. Ag emerged as a critical contributor at higher temperatures, significantly enhancing photocatalytic performance. The photocatalytic system exhibited a departure from Arrhenius behavior, with an optimal temperature of 40°C. Binary doping systems, particularly those combining CdO and ZnO, demonstrated exceptional photocatalytic activity at lower temperatures. However, the ternary doping configuration involving Ag, CdO, and ZnO proved to be the most promising, surpassing many functional materials. In sum, this study offers valuable insights into how Schottky barriers, Z-scheme systems, and type II heterojunctions, in conjunction with specific dopants, can overcome the electron-hole recombination challenge in TiO2-based photocatalysis. The results underscore the potential of the proposed ternary doping system to revolutionize photocatalytic water splitting for efficient green hydrogen production, significantly advancing the field's understanding and potential for sustainable energy applications.

N/O/P ternary-doped coal-based hierarchical porous carbon networks for high lithium-ion storage performance

Constructing porous structure and surface modification are effective ways to enhance the Li-ion storage performance of commercial graphite anode for lithium-ion batteries (LIBs). Herein, nitrogen, oxygen and phosphorus ternary-doped coal-based hierarchical porous carbon networks (N/O/P-CCNs) were prepared through liquid oxidation combined with self-assembly method. The N/O/P-CCNs have a three-dimensional porous carbon network structure formed by cross-linking carbon nanosheets with an appropriate specific surface area (321 m2 g−1) and distribution of micro-, meso- and macropore, while the surfaces of carbon nanosheets are doped with nitrogen, oxygen and phosphorus. Due to unique hierarchical porous structure and the synergistic effect of ternary doping, the N/O/P-CCNs anode exhibits excellent Li-ion storage properties with initial reversible capacity of 1079 mAh g−1, which is much higher than that of coal-based graphite anode (382 mAh g−1). Besides, the N/O/P-CCNs anode also has superior rate capability (336 and 275 mAh g−1 at 1.0 and 2.0 A g−1) and cycle stability with a high capacity retention (near 100 % after 100 cycles). The excellent electrochemical performance is not only related to the hierarchical pore structure that can provide efficient channels for lithium-ion transport, but also to the ternary-doping of nitrogen, oxygen and phosphorus that can provide more active sites for lithium-ion storage and enhance conductivity. This work provides a novel and effective design strategy for developing high-performance anode materials for LIBs.

Synthesis and Evaluation of Boron, Cerium, and Silver Ternary Doped Titanium Dioxide Photocatalysts for Degradation of Ciprofloxacin (CIP) Antibiotic under UV - A Irradiation

Synthesis and Evaluation of Boron, Cerium, and Silver Ternary Doped Titanium Dioxide Photocatalysts for Degradation of Ciprofloxacin (CIP) Antibiotic under UV - A Irradiation

Tunable multicolor afterglow including white light emission from poly(acrylic acid)-based room temperature phosphorescence materials via phosphorescence FRET

Room temperature phosphorescence (RTP) materials with multicolor afterglow emission have important application potential in multicolor display and anti-counterfeiting. However, the preparation of polymer-based multicolor RTP materials still faces challenges. In this work, we prepare a kind of ultralong RTP materials by facilely doping phthalimide (Pth) into poly (acrylic acid) (PAA) matrices based on the hydrogen-bonding interaction. Attributed to the wide phosphorescence emission band of PAA-Pth, the ternary doping systems are constructed by using PAA-Pth as donors and commercially available fluorescent dyes rhodamine B (RhB) or fluorescein (FL) as acceptors, which display multicolor afterglow from cyan to red and green through efficient phosphorescence Förster resonance energy transfer (FRET). More impressively, the quaternary doping systems PAA-Pth-RhB-FL with different molar ratios of FL exhibit tunable multicolor afterglow, including nearly white afterglow emission. Due to the different FRET efficiency of PAA-based multicolor RTP materials at different excitation wavelengths, they are successfully applied in color information encryption.

Liquid‐phase sintering of ZrO2‐based nanocrystalline glass–ceramics achieved by multielement co‐doping

AbstractLiquid‐phase sintering (LPS) is an effective pathway to assist the densification of ceramics. However, it has seldom been used to densify glass–ceramics. In the present study, a multielement co‐doping strategy has been utilized to achieve LPS of a ZrO2–SiO2 nanocrystalline glass–ceramic. Compared with undoped samples densified by solid‐state sintering, doping of equimolar Al, Y, and Ca promoted the densification of the glass–ceramic at lower temperatures with a faster densification rate. Ternary doping enhanced coarsening of ZrO2 nanocrystallites during sintering and annealing. The distribution of dopants was carefully observed with X‐ray energy‐dispersive spectrometry technique in scanning electron transmission microscopy mode. Results showed that the three dopants showed different distribution behaviors. After sintering, Y dopants were predominately distributed in ZrO2 nanocrystallites, whereas parts of Al and Ca dopants were distributed in ZrO2 nanocrystallites and part of them co‐segregated at the ZrO2/SiO2 heterointerfaces. Meanwhile, the segregation of Ca dopant at some intergranular films among ZrO2 nanocrystallites was observed. Redistribution of dopants did not occur during annealing.

Ternary doping of Na+, Bi3+ and La3+ to improve piezoelectric constant and electrical resistivity simultaneously in calcium bismuth niobate ceramics

High Curie-temperature layer-structured calcium bismuth niobate (CaBi2Nb2O9) piezoelectric ceramics are promising for important application in high-temperature vibration sensors. However, such application is currently limited due to not only poor high-temperature piezoelectric constant (d33), which is attributable to spontaneous polarization along a-b plane and high coercive fields, but also inferior high-temperature electrical resistivity, which results from volatilization of Bi2O3 during the sintering process that increases defect concentration of oxygen vacancies. Herein, we report a Na+, Bi3+ and La3+ ternary-doping-strategy to obtain Ca0.8(Na0.5La0.3Bi0.2)0.2Bi2Nb2O9 ceramics, which exhibited higher piezoelectric constant and larger electrical resistivity as accompanied by a better thermal stability at high-temperatures. The piezoelectric constant was enhanced from 8.8 pC/N in pristine CaBi2Nb2O9 to 13.4 pC/N in Ca0.8(Na0.5La0.3Bi0.2)0.2Bi2Nb2O9 ceramics, which is ascribed to the presence of pseudo-tetragonal structural distortion after La3+ doping. In addition, the electrical resistivity at 600 °C was increased by more than one-order of magnitude from 3.7 × 104 Ω cm in pristine CaBi2Nb2O9 to 1.4 × 106 Ω cm in Ca0.8(Na0.5La0.3Bi0.2)0.2Bi2Nb2O9 ceramics. Such significant improvement in electrical resistivity results from the reduction in oxygen vacancies due to ternary doping of Na+, Bi3+ and La3+ and stronger binding interaction between La3+ dopants and O2− in (Bi2O2)2+ layers in Ca0.8(Na0.5La0.3Bi0.2)0.2Bi2Nb2O9 ceramics. This work demonstrates an important way of employing chemical doping to improve piezoelectric constant and electrical resistivity simultaneously at high-temperatures to tune structural distortion in bismuth-layered structural CaBi2Nb2O9 ceramics.

Improving the hydrogen evolution reaction activity of molybdenum-based heterojunction nanocluster capsules via electronic modulation by erbium–nitrogen–phosphorus ternary doping

The realization of a hydrogen-based economy with robust hydrogen evolution reaction catalysts remains a challenge. In this study, we prepared MoO2/Mo2N3 heterostructure nanoclusters co-doped with nitrogen, phosphorus, and erbium for the first time. The introduction of the nitrogen and phosphorus atoms into the transition metal increases the d-electron density and contracts the d-band, which leads to a rearranged electronic structure of the MoO2/Mo2N3 heterojunction. The coupling of the rare earth erbium dopant with the valence band of the heterojunction leads to the redistribution of the electron density in the catalyst and promotes covalent interaction with the adsorbed intermediates, thereby optimizing the Gibbs free energy of intermediate adsorption and improving the catalytic activity for the hydrogen evolution reaction. Not only is an efficient and economical catalyst for electrolytic aquatic hydrogen production provided in this work, but a new synthesis scheme is also proposed for the rational synthesis of homologous core–shell polymetallic nanostructures with broad application prospects.

Hierarchical porous nitrogen, oxygen, and phosphorus ternary doped hollow biomass carbon spheres for high‐speed and long‐life potassium storage

AbstractLimited lithium resources have promoted the exploration of new battery technologies. Among them, potassium‐ion batteries are considered as promising alternatives. At present, commercial graphite and other carbon‐based materials have shown good prospects as anodes for potassium‐ion batteries. However, the volume expansion and structural collapse caused by periodic K+ insertion/extraction have severely restricted further development and application of potassium‐ion batteries. A hollow biomass carbon ball (NOP‐PB) ternarily doped with N, O, and P was synthesized and used as the negative electrode of a potassium‐ion battery. X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectroscopy, and transmission electron microscopy confirmed that the hollow biomass carbon spheres were successfully doped with N, O, and P. Further analysis proved that N, O, and P ternary doping expands the interlayer distance of the graphite surface and introduces more defect sites. DFT calculations simultaneously proved that the K adsorption energy of the doped structure is greatly improved. The solid hollow hierarchical porous structure buffers the volume expansion of the potassium insertion process, maintains the original structure after a long cycle and promotes the transfer of potassium ions and electrons. Therefore, the NOP‐PB negative electrode shows extremely enhanced electrochemical performance, including high specific capacity, excellent long‐term stability, and good rate stability.

Reactive sintered highly transparent AlON ceramics with Y2O3‐MgAl2O4‐H3BO3 ternary additive

AbstractIn this study, highly transparent aluminate oxynitride (AlON) ceramics were prepared via the reactive sintering of Al2O3 and AlN powders using a Y2O3‐MgAl2O4‐H3BO3 ternary sintering additive. The ternary doping process resulted in the efficient preparation of transparent AlON ceramics with small grains and high transmittance as compared to the binary doping (Y2O3‐MgAl2O4) process. The addition of 0.1 wt.% Y2O3‐0.4 wt.% MgAl2O4‐0.12 wt.% H3BO3 resulted in the formation of a 4‐mm‐thick AlON ceramic with high transmittance (81% at 600 nm) and low haze (3.46%). This is the best performance in terms of the thickness and transmittance reported for AlON transparent ceramics prepared by the reactive sintering method.

Host–guest materials with room temperature phosphorescence: Tunable emission color and thermal printing patterns

AbstractThe research of purely organic materials with long afterglow has drawn more and more attention, especially for those with stimulus‐response characteristic. So far, this kind of material is really very scarce and their performance is not good enough. In this study, we successfully developed an efficient heating‐responsive room‐temperature phosphorescence material with phosphorescence efficiency and lifetime up to 13.4% and 2.08 s through the simple host–guest doping strategy. Further on, by introducing the additional energy acceptor of fluorescein with concentration‐dependent emission to construct ternary doping systems, the afterglow color was extended from blue to yellow. Accordingly, the multicolor thermal printings have been easily realized, showing the great practical application prospects.

Enhanced Electrochemical Performance of a Hybrid Supercapacitive Material Based on Ternary Doped Polyaniline/Activated Carbon Composite

A facile strategy for synthesizing a highly performing hybrid supercapacitor electrode material by combining ternary doped (binary transition metals in combination with an inorganic acid) polyanili...

Early activation of high volume fly ash by ternary activator and its activation mechanism

To solve the problems of low early strength and severe plastic cracking caused by high volume fly ash used in cement-based materials. Triethanolamine (TEA), calcium hydroxide (Ca(OH)2), and sodium silicate (Na2SiO3) or sodium sulfate (Na2SO4) were selected to conduct a ternary doping test. The compressive strength of samples was measured to determine the best ratio, content, and time effect of the activator, and its action mechanism was studied by various micro test. The quantitative calculation model of main hydration products was established in the fly ash-cement system. Based on the simulation of molecular dynamics, the structure of NASH gel was studied under alkali activation. The results show that the optimal mixing mass ratio of TEA:Ca(OH)2:Na2SiO3 is 2:75:25 and the optimal dosage is 1.02% of the cementitious material. There are a large number of needle-like ettringite, petaloid hydrated calcium aluminate and clusters of hydrated calcium silicate gel in the system, whereas the amount of plate-like CH decreased significantly at hydration for 14 days. The Si/Al is three and aluminium coordination is predominantly tetrahedral, and the order of bonds stability and atoms mobility are Si–O > Al–O > Na–O and Na > O > Al> in the NASH gel, respectively. Under the Na+ and alkali environment, the Si(OH)4 and Al(OH)4- formed polycondensation reaction to reform polymers Si–O–Si and Al–O–Si, forming a large amount of NASH gel.

A general doping rule: rational design of Ir-doped catalysts for the oxygen evolution reaction.

Revealing how to rationally select a suitable dopant or the host counterpart is greatly important for optimizing the catalytic activity of transition metal oxides (TMOs). We systematically report the adsorption trends of atomic O and H, two selected representative adsorbates, on numerous doped rutile-type TMO surfaces under two different doping modes, aiming to demonstrate adsorption energy (AE) variations of different adsorbates across doped TMO surfaces. A "host-guest interaction" induced adsorption tuning rule for the ternary doping systems is identified, which rationally directs the proposal of cost-effective Ir-doped CrO2 or MnO2 catalysts for the electrocatalytic oxygen evolution reaction compared with the common IrO2.

Template synthesis of two-dimensional ternary nickel-cobalt-nitrogen co-doped porous carbon film: Promoting the conductivity and more active sites for oxygen reduction

Rational design of a stable, highly active non-precious metal-based electrocatalysts for oxygen reduction reaction (ORR) is vitally important for industrial application of fuel cells technology. As a potential alternative of Pt/C catalyst, two-dimensional (2D) porous carbon materials are widely investigated due to the highly accessible surface area and active sites, wherein carbon films doped with a plurality of metals and non-metal elements are rarely reported due to an uncontrollable synthesis process. Here, a bi-metallic (NiCo alloy nanoparticles) and nonmetallic (N) co-doped porous carbon film (Ni-Co-N@CF) is fabricated by a simple controllable and scalable strategy comprising the synthesis of NiCo alloy nanoparticles, modification of organic molecules, and high-temperature carbonization process. The optimized Ni-Co-N@CF catalyst shows an excellent ORR electrocatalytic activity with a larger electrochemically active surface area (2.31 m2 g−1), a higher half-wave potential (0.86 V) and a lower diffusion limited current density (−4.43 mA cm−2) than all the prepared control catalysts. Moreover, the designated catalyst also exhibits high durability and superior methanol tolerance in alkaline media, significantly better than the commercial Pt/C (20 wt%). The superior ORR performance is attributed to the synergetic interactions of ternary doping of Ni/Co/N in the 2D film skeleton, which not only greatly enhances conductivity but also provides more Co-N active sites.