Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The a...Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.展开更多
An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)an...An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)and two polarity gates(PG1 and PG2).Utilizing the polarity bias concept,a narrow N^(+)pocket is formed between the source and channel without the need for additional doping steps,achieved through biasing PG1 and PG2 at-1.2 V and 1.2 V,respectively.This method not only addresses issues related to doping control but also eliminates constraints associated with thermal budgets and simplifies the fabrication process compared to traditional TFETs.To facilitate biomolecule sensing within the device,a nanogap cavity is formed in the gate dielectric by selectively etching a section of the polarity gate dielectric layer toward the source side.The investigation into the presence of neutral and charged molecules within the cavities has been conducted by examining variations in the electrical properties of the proposed biosensor.Key characteristics assessed include drain current,energy band,and electric field distribution.The performance of the biosensor is measured using various metrics such as drain current(I_(DS)),subthreshold swing(SS),threshold voltage(V_(TH)),drain current ratio(I_(ON)/I_(OFF)).The proposed in-built N^(+)pocket ED-TFET-based biosensor reaches a peak sensitivity of 1.08×10~(13)for a neutral biomolecule in a completely filled nanogap with a dielectric constant of 12.Additionally,the effects of cavity geometry and different fill factors(FFs)on sensitivity are studied.展开更多
The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0....The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0.36,we studied the kagome-lattice t-J model using state-of-the-art density matrix renormalization group calculations.On the L_(y)=3 cylinder(Ly is the number of unit cells along the circumferential direction),we established a quantum phase diagram with an increasing doping level.In addition to the charge density wave states at lower doping levels,we found an emergent Fermi-liquid-like phase by melting the holon Wigner crystal at δ≈0.15,which is characterized by the suppression of charge density oscillation and power-law decay of various correlation functions.For a wider L_(y)=4 cylinder,the bond-dimension extrapolated correlation functions also support such a Fermi-liquid-like state,suggesting its stability with increasing system size.In a narrow doping range near δ=1/3 for the L_(y)=3 cylinder,we find a state with an exponential decay of the single-particle correlation,but the other correlation functions preserve the features in the Fermi-liquid-like phase,which may be a precursor of a superconducting state.Nevertheless,this peculiar state nearδ=1/3 disappears for the L_(y)=4 cylinder,implying a possible lattice-size dependence.Our results reveal quantum melting from a holon Wigner crystal to a Fermi-liquid-like state with increasing hole density and suggest a doping regime to explore superconductivity in future studies.展开更多
We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber p...We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber provides the gain.The chaotic laser was pumped by the laser diodes with the maximum power of 150 mW at the wavelength of 850 nm.The peak fluorescence spectrum of Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber at the wavelength of 635 nm shows that the visiblewavelength fiber laser can be achieved by synergistic energy transfer between Pr~(3+)and Yb^(3+)ions.The chaotic fiber laser is generated by adjusting the pump power,polarization controller and the auto-correlation,permutation entropy,skewness,and kurtosis were used to analyze the characteristics of chaotic laser.The noise-like time series and delta-like auto-correlation curve indicate the chaotic output.The complexity and randomness of time series are analyzed by the permutation entropy,skewness,and kurtosis.The result shows that chaotic dynamics is stable when the pump power exceeds a certain value.The visible chaotic all-fiber laser has high stability and can be applied for real-time monitoring and sensing.We believe that this approach may also be feasible for other materials for emission in the visible range.展开更多
Visible light photocatalytic degradation is a promising advanced oxidation process for the removal of antibiotics in wastewater.However,this technology currently has problems that are not suitable for large-scale appl...Visible light photocatalytic degradation is a promising advanced oxidation process for the removal of antibiotics in wastewater.However,this technology currently has problems that are not suitable for large-scale applications,mainly due to the high cost of development and preparation of efficient photocatalysts.Therefore,the preparation of low-cost,high-efficiency and environmentally friendly semiconductor photocatalysts is still a hot research topic.In this study,rare earth metal Ce-doped porous Bi_(2)O_(3)-based biomorphic photocatalysts were prepared by a combination of solvothermal method and tem plate method using natural rapeseed pollen as a green template.Ce/Bi_(2)O_(3) synthesized by the optimal process shows a pollen-shaped porous stru cture with high dispersion and integrity,high purity and large specific surface area.Ce in the catalysts with different doping amounts coexists in two mixed valence states of Ce^(4+)and Ce^(3+),and Ce doping increases the percentage of oxygen vacancies.The higher specific surface area of the catalyst also provides more active sites and reaction surface area.When the doping amount of Ce is 5 mol%,the efficiency of tetracycline hydrochloride(TCH)degradation under visible light can reach more than 96%after 180 min.The rate constant is 6.37 times higher than that of commercially available Bi_(2)O_(3)(CHB).Through the analysis of intermediate products,the possible degradation path of TCH is obtained,and the phenomenon of intermediate accumulation in the initial stage was explored.The prepared photocatalysts have excellent stability and high reusability,and have a large advantage in comprehensive economy.Therefore,this study provides a reference for the preparation of low-cost rare earth metal doped photocatalysts with special morphology for the degradation of antibiotic wastewater.展开更多
Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates sign...Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates significantly at elevated temperatures exceeding 600℃,primarily due to the collapse of pore structure.Meanwhile,the shielding capacity of SiO_(2) aerogel to the infrared radiation at high temperature is rather low due to the intrinsic properties of SiO_(2).Herein,a strategy for improving the high-temperature stability and infrared shielding properties of SiO_(2) aerogel via Ca doping was explored.Calcium-doped silica aerogel(CSA)powders were prepared by Sol-Gel,hydrothermal,and ambient pressure drying(APD)techniques using water glass and anhydrous calcium chloride as precursors and trimethylchlorosilane as a hydrophobic modifier.The effects of Ca/Si molar ratio in the precursor and hydrothermal conditions(temperature and pH)on the crystalline properties,microscopic morphology and pore structure of CSAs were investigated.The results show that the Ca/Si molar ratio and hydrothermal treatment have significant effects on the microstructure and heat resistance of CSAs in the temperature range of 400-1000℃.The samples sintered at 1000℃have a high specific surface area of 100.1 m^(2)/g and a pore volume of 0.8705 cm^(3)/g,indicating that the CSA has good heat resistance.One-side insulation tests at temperatures up to 600℃show that the sample with a Ca/Si molar ratio of 1.0 has the best insulation performance,with a cold surface temperature of 450℃,which is 27℃lower than that of the pure silica aerogel.展开更多
Synthetic dyes,particularly azo dyes,pose significant environmental and health risks due to their persistence,toxicity,and potential carcinogenicity.Zinc oxide(ZnO)is a promising photocatalyst for wastewater remediati...Synthetic dyes,particularly azo dyes,pose significant environmental and health risks due to their persistence,toxicity,and potential carcinogenicity.Zinc oxide(ZnO)is a promising photocatalyst for wastewater remediation,but its wide bandgap and rapid charge recombination limit its practical efficacy.Furthermore,conventional doping methods often rely on hazardous chemical precursors,undermining the sustainability of the overall approach.This review introduces a novel and sustainable paradigm:the utilization of biomass-derived precursors as green reagents for the in-situ synthesis and simultaneous phosphorus-nitrogen(P-N)co-doping of ZnO nanoparticles.We critically analyze how the intrinsic biochemical composition of biomass,rich in P,N,and other heteroatoms,facilitates this one-pot,eco-friendly functionalization.This integrated strategy merges the performance enhancement offered by advanced co-doping,such as extended visible-light absorption and suppressed charge recombination,with the core principles of green chemistry and circular economy.It offers a dual benefit:creating highly effective photocatalysts for the degradation of persistent pollutants and valorizing abundant agricultural or biological waste streams.Our comprehensive evaluation goes beyond description to critically assess the underlying mechanisms,comparative efficacy,scalability challenges,and future research directions of this emerging field.This review underscores the unique contribution of biomass-mediated synthesis to advancing sustainable nanotechnology for environmental applications.展开更多
Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently wor...Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.展开更多
Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthes...Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.展开更多
MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper...MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper doping and carbon-based confinement.Residual carbon(RC),derived from acid-washed coal gasification fine slag(CGFS),serves as a conductive and porous framework for the directional growth of Cu-doped MnO_(2) nanowires(CMO@RC).The synergistic modulation of Cu-induced electronic structure tuning and carbon confinement induced mechanical/electrical stabilization significantly enhances Zn^(2+) transport and electrochemical performance.CMO@RC achieves a high capacity of 563 mA·h·g^(−1) at 0.1 A·g^(−1) and maintains 106%after 1000 cycles at 1 A·g^(−1).Kinetic analyses confirm the dual-path Zn^(2+) diffusion and accelerated reaction kinetics,while DFT calculations reveal that Cu doping enhances Mn 3d orbital hybridization and electron interaction with carbon,elevating the density of states near the Fermi level and reducing charge transfer barriers.Furthermore,pouch cell testing demonstrates outstanding flexibility and mechanical resilience.This study provides a cost-effective and scalable strategy for high-performance AZIBs,leveraging both experimental and theoretical validations.展开更多
Seawater electrolysis is an appealing route toward sustainable hydrogen production,yet its practical deployment is hindered by severe chloride-induced corrosion and parasitic chlorine oxidation.Here,we report noble me...Seawater electrolysis is an appealing route toward sustainable hydrogen production,yet its practical deployment is hindered by severe chloride-induced corrosion and parasitic chlorine oxidation.Here,we report noble metal-doped NiV layered double hydroxides(LDHs)that integrate electronic modulation with a dual chloride confinement mechanism.Ir incorporation simultaneously establishes strong Ir-Cl coordination and dynamically regenerated VO_(4)^(3-)layers,producing an adaptive electrostatic shield that effectively suppresses chloride penetration.As a result,Ir-NiV LDH delivers nearly 100%oxygen evolution reaction selectivity and outstanding stability over2750 h at 500 mA cm^(-2).Meanwhile,Ru doping optimizes the hydrogen evolution pathway,enabling a low overpotential of 195 mV and>2350 h durability.When paired in a twso-electrode electrolyzer,the Ru-NiVLDH‖Ir-NiVLDH system exhibits industrial-level performance and unprecedented robustness in alkaline seawater.This dual chloride confinement concept provides a general framework for catalyst design in corrosive ionic environments,extending beyond seawater splitting toward other electrochemical energy conversion processes.展开更多
The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demons...Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.展开更多
We investigate the interplay between the pseudogap state and d-wave superconductivity in the two-dimensional doped Hubbard model by employing an eight-site cluster dynamical mean-field theory method.By tuning electron...We investigate the interplay between the pseudogap state and d-wave superconductivity in the two-dimensional doped Hubbard model by employing an eight-site cluster dynamical mean-field theory method.By tuning electron hopping parameters,the strong-coupling pseudogap in the two-dimensional Hubbard model can be either enhanced or suppressed in the doped Mott insulator regime.We find that in underdoped cases,the closing of pseudogap leads to a significant enhancement of superconductivity,indicating competition between the two in the underdoped regime.In contrast,at large dopings,suppressing the pseudogap is accompanied by a concurrent decrease in the superconducting transition temperature Tc,which can be attributed to a reduction in antiferromagnetic correlations behind both the pseudogap and superconductivity.We elucidate this evolving relationship between pseudogap and superconductivity across different doping regimes.展开更多
By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering met...By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.展开更多
Miniaturized erbium-doped waveguide amplifiers attracted great interests in recent decades due to their high gain-efficiency and function-scalability in the telecom C-band.In this work,an erbium-doped thin film lithiu...Miniaturized erbium-doped waveguide amplifiers attracted great interests in recent decades due to their high gain-efficiency and function-scalability in the telecom C-band.In this work,an erbium-doped thin film lithium niobate waveguide amplifier achieving>10 dB off-chip(fiber-to-fiber)net gain and>20 mW fiber-output amplified power is demonstrated,thanks to the low-propagation-loss waveguides and robust waveguide edge-couplers prepared by the photolithography assisted chemomechanical etching technique.Systematic investigation on the fabricated waveguide amplifiers reveals remarkable optical gain around the peak wavelength of 1532 nm as well as the low fiber-coupling loss of-1.2 dB/facet.A fiber Bragg-grating based waveguide laser is further demonstrated using the fabricated waveguide amplifier as the external gain chip,which generates>2 mW off-chip power continuous-wave lasing around the gain peak at 1532 nm.The unambiguous demonstration of fiber-to-fiber net gain of the erbium-doped thinfilm lithium niobate(TFLN)waveguide amplifier as well as its external gain chip application will benefit diverse fields demanding scalable gain elements with highspeed tunability.展开更多
Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high curr...Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high current densities.Herein,a Pr-doped Co(OH)_(2)hexagonal sheet(Pr/Co=1/9,in mole)is synthesized by electrodeposition as highly performant catalyst for 5-hydroxymethylfurfural(HMF)oxidation reaction(HMFOR)to produce 2,5-furandicarboxylic acid(FDCA).This novel and low-cost catalyst possesses a rather low onset potential of 1.05 V(vs.RHE)and requires only 1.10 V(vs.RHE)to reach a current density of 10 mA cm^(-2)for HMFOR,significantly outperforming Co(OH)_(2)benchmark(i.e.,210 mV higher to reach10 m A cm^(-2)).The origin of Pr promotion effect as well as the evolution of CoOOH catalytic sites and HMFOR process has been deeply elucidated by physical characterizations,kinetic experiments,in situ electrochemical techniques,and theoretical calculations.The unique Pr-ameliorated CoOOH active centers enable 100%conversion of HMF,99.6%selectivity of FDCA,and 99.7%Faraday efficiency,with a superior cycling durability toward HMFOR.This can be one of the most outstanding results for Co-based HMFOR catalysts to date in the literature.Thereby this work can help open up new horizons for constructing novel and efficient Co-based electrocatalysts by the utilization of lanthanide elements.展开更多
In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not ...In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.展开更多
We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.C...We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.Compared with single N-doped BCDs(N-BCDs) and Pr-doped BCDs(Pr-BCDs),Pr/N-BCDs not only showed better fluorescence properties and stability but also achieved a significant increase in quantum yield of 12%.More importantly,under certain conditions,Pr/N-BCDs and 2,4-dinitrophenylhydrazide(2,4-DNPH) had significant fluorescence internal filtration effect(IFE) and dynamic quenching effect,and in the concentration range of0.50-20 μmol·L^(-1),the concentration of 2,4-DNPH had a good linear relationship with the fluorescence quenching signal,and the detection limit was as low as 2.1 nmol·L^(-1).展开更多
N-doped graphite carbon sphere coated cobalt nanoparticle catalyst(Co@C-N-900),prepared by solvothermal-calcination method,is applied to activate peroxymonosulfate(PMS)for bisphenol A(BPA)elimination.The outcomes demo...N-doped graphite carbon sphere coated cobalt nanoparticle catalyst(Co@C-N-900),prepared by solvothermal-calcination method,is applied to activate peroxymonosulfate(PMS)for bisphenol A(BPA)elimination.The outcomes demonstrate that the Co@C-N-900 could effectively activate PMS,thereby causing efficient removal of BPA in water.In addition,the Co@C-N-900/PMS system also has the advantages of low metal leaching,applicability in high salinity environments,good selectivity and stability.Further investigations using electron paramagnetic resonance,chronoamperometry,and quenching experiments demonstrated that the Co@C-N-900/PMS system is a typical non-radical route with singlet oxygen(^(1)O_(2))as the main reactive oxygen species(ROS).Density functional theory calculations(DFT)indicate that N-doping can effectively regulate the charge distribution on the catalyst surface,generating acidic/alkaline sites favorable for PMS adsorption and activation.Furthermore,it also can enhance the interaction and charge transfer capacity between the Co@C-N-900 and PMS.Lastly,LC-QTOF-MS/MS analysis revealed two possible BPA degradation pathways:(1)^(1)O_(2)attacked the isopropyl group in BPA between the two phenyl groups,causingβ-scission to occur.(2)Following the oxidation of the hydroxyl group in the aromatic ring of BPA,^(1)O_(2)could cause furtherβ-scission.The prepared Co@C-N-900 catalyst is a very promising catalyst,which would offer a workable remedy for treating water pollution.展开更多
文摘Herein,antibacterial silver‑doped fluorescent carbon dots(Ag‑CDs)were synthesized through a stepwise hydrothermal method,with polyethyleneimine(PEI),citric acid(CA),and silver nitrate(AgNO3)serving as precursors.The applicability and antimicrobial efficacy of these nanomaterials were systematically investigated for metal ion sensing.Experimental evidence demonstrated that the Ag‑CDs exhibited a pronounced fluorescence quenching response toward ferric ions(Fe^(3+)),enabling their quantitative determination via a linear concentration‑dependent relationship.These Ag‑CDs exhibited significant inhibitory effects on biofilm growth and disruption for both Escherichia coli and Staphylococcus aureus.Mechanism investigations indicate that Ag‑CDs induced the death of Escherichia coli and Pseudomonas aeruginosa by disrupting their bacterial morphology and structure,triggering the generation of intracellular reactive oxygen species(ROS),and impairing their antioxidant defense system.
基金Project supported by the Ministry of Education’s Supply and Demand Matching Employment and Education Project(Grant No.2024110776329)。
文摘An in-built N^(+)pocket electrically doped tunnel field-effect transistor(ED-TFET)-based biosensor has been reported for the first time.The proposed device begins with a PN junction structure with a control gate(CG)and two polarity gates(PG1 and PG2).Utilizing the polarity bias concept,a narrow N^(+)pocket is formed between the source and channel without the need for additional doping steps,achieved through biasing PG1 and PG2 at-1.2 V and 1.2 V,respectively.This method not only addresses issues related to doping control but also eliminates constraints associated with thermal budgets and simplifies the fabrication process compared to traditional TFETs.To facilitate biomolecule sensing within the device,a nanogap cavity is formed in the gate dielectric by selectively etching a section of the polarity gate dielectric layer toward the source side.The investigation into the presence of neutral and charged molecules within the cavities has been conducted by examining variations in the electrical properties of the proposed biosensor.Key characteristics assessed include drain current,energy band,and electric field distribution.The performance of the biosensor is measured using various metrics such as drain current(I_(DS)),subthreshold swing(SS),threshold voltage(V_(TH)),drain current ratio(I_(ON)/I_(OFF)).The proposed in-built N^(+)pocket ED-TFET-based biosensor reaches a peak sensitivity of 1.08×10~(13)for a neutral biomolecule in a completely filled nanogap with a dielectric constant of 12.Additionally,the effects of cavity geometry and different fill factors(FFs)on sensitivity are studied.
基金supported by the National Natural Science Foundation of China (Grant Nos.12274014 and 12534009)the Guangdong Provincial Quantum Science Strategic Initiative (Grant No.GDZX2501006)+4 种基金the Special Project in Key Areas for Universities in Guangdong Province (Grant No.2023ZDZX3054)the Dongguan Key Laboratory of Artificial Intelligence Design for Advanced Materialssupported by the U.S.Department of Energy,Office of Basic Energy Sciences (Grant No.DE-FG02-06ER46305) for DMRG studies on unconventional superconductivitysupported by the SongShan Lake HPC Center (SSL-HPC) at Great Bay University (X.Y.J.and S.S.G.)supported in part by the US National Science Foundation (Grant No.DMR-2406524) (D.N.S.)。
文摘The doped quantum spin liquid on the kagome lattice provides a fascinating platform to explore exotic quantum states,such as the reported holon Wigner crystal at low doping.By extending the doping range toδ=0.027–0.36,we studied the kagome-lattice t-J model using state-of-the-art density matrix renormalization group calculations.On the L_(y)=3 cylinder(Ly is the number of unit cells along the circumferential direction),we established a quantum phase diagram with an increasing doping level.In addition to the charge density wave states at lower doping levels,we found an emergent Fermi-liquid-like phase by melting the holon Wigner crystal at δ≈0.15,which is characterized by the suppression of charge density oscillation and power-law decay of various correlation functions.For a wider L_(y)=4 cylinder,the bond-dimension extrapolated correlation functions also support such a Fermi-liquid-like state,suggesting its stability with increasing system size.In a narrow doping range near δ=1/3 for the L_(y)=3 cylinder,we find a state with an exponential decay of the single-particle correlation,but the other correlation functions preserve the features in the Fermi-liquid-like phase,which may be a precursor of a superconducting state.Nevertheless,this peculiar state nearδ=1/3 disappears for the L_(y)=4 cylinder,implying a possible lattice-size dependence.Our results reveal quantum melting from a holon Wigner crystal to a Fermi-liquid-like state with increasing hole density and suggest a doping regime to explore superconductivity in future studies.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61975141,61575137,and61675144)。
文摘We investigate theoretically and experimentally the chaotic dynamics of visible-wavelength all-fiber ring laser.The100-m 630 HP fibers are used to ensure high non-linearity.A 4-m Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber provides the gain.The chaotic laser was pumped by the laser diodes with the maximum power of 150 mW at the wavelength of 850 nm.The peak fluorescence spectrum of Pr^(3+)/Yb^(3+)-co-doped ZBLAN fiber at the wavelength of 635 nm shows that the visiblewavelength fiber laser can be achieved by synergistic energy transfer between Pr~(3+)and Yb^(3+)ions.The chaotic fiber laser is generated by adjusting the pump power,polarization controller and the auto-correlation,permutation entropy,skewness,and kurtosis were used to analyze the characteristics of chaotic laser.The noise-like time series and delta-like auto-correlation curve indicate the chaotic output.The complexity and randomness of time series are analyzed by the permutation entropy,skewness,and kurtosis.The result shows that chaotic dynamics is stable when the pump power exceeds a certain value.The visible chaotic all-fiber laser has high stability and can be applied for real-time monitoring and sensing.We believe that this approach may also be feasible for other materials for emission in the visible range.
基金Project supported by the National Natural Science Foundation of China(42377405,41877477)Director's Funds of Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration(SHUES2022C01)。
文摘Visible light photocatalytic degradation is a promising advanced oxidation process for the removal of antibiotics in wastewater.However,this technology currently has problems that are not suitable for large-scale applications,mainly due to the high cost of development and preparation of efficient photocatalysts.Therefore,the preparation of low-cost,high-efficiency and environmentally friendly semiconductor photocatalysts is still a hot research topic.In this study,rare earth metal Ce-doped porous Bi_(2)O_(3)-based biomorphic photocatalysts were prepared by a combination of solvothermal method and tem plate method using natural rapeseed pollen as a green template.Ce/Bi_(2)O_(3) synthesized by the optimal process shows a pollen-shaped porous stru cture with high dispersion and integrity,high purity and large specific surface area.Ce in the catalysts with different doping amounts coexists in two mixed valence states of Ce^(4+)and Ce^(3+),and Ce doping increases the percentage of oxygen vacancies.The higher specific surface area of the catalyst also provides more active sites and reaction surface area.When the doping amount of Ce is 5 mol%,the efficiency of tetracycline hydrochloride(TCH)degradation under visible light can reach more than 96%after 180 min.The rate constant is 6.37 times higher than that of commercially available Bi_(2)O_(3)(CHB).Through the analysis of intermediate products,the possible degradation path of TCH is obtained,and the phenomenon of intermediate accumulation in the initial stage was explored.The prepared photocatalysts have excellent stability and high reusability,and have a large advantage in comprehensive economy.Therefore,this study provides a reference for the preparation of low-cost rare earth metal doped photocatalysts with special morphology for the degradation of antibiotic wastewater.
文摘Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density,low thermal conductivity and high stability.However,its thermal insulation performance deteriorates significantly at elevated temperatures exceeding 600℃,primarily due to the collapse of pore structure.Meanwhile,the shielding capacity of SiO_(2) aerogel to the infrared radiation at high temperature is rather low due to the intrinsic properties of SiO_(2).Herein,a strategy for improving the high-temperature stability and infrared shielding properties of SiO_(2) aerogel via Ca doping was explored.Calcium-doped silica aerogel(CSA)powders were prepared by Sol-Gel,hydrothermal,and ambient pressure drying(APD)techniques using water glass and anhydrous calcium chloride as precursors and trimethylchlorosilane as a hydrophobic modifier.The effects of Ca/Si molar ratio in the precursor and hydrothermal conditions(temperature and pH)on the crystalline properties,microscopic morphology and pore structure of CSAs were investigated.The results show that the Ca/Si molar ratio and hydrothermal treatment have significant effects on the microstructure and heat resistance of CSAs in the temperature range of 400-1000℃.The samples sintered at 1000℃have a high specific surface area of 100.1 m^(2)/g and a pore volume of 0.8705 cm^(3)/g,indicating that the CSA has good heat resistance.One-side insulation tests at temperatures up to 600℃show that the sample with a Ca/Si molar ratio of 1.0 has the best insulation performance,with a cold surface temperature of 450℃,which is 27℃lower than that of the pure silica aerogel.
文摘Synthetic dyes,particularly azo dyes,pose significant environmental and health risks due to their persistence,toxicity,and potential carcinogenicity.Zinc oxide(ZnO)is a promising photocatalyst for wastewater remediation,but its wide bandgap and rapid charge recombination limit its practical efficacy.Furthermore,conventional doping methods often rely on hazardous chemical precursors,undermining the sustainability of the overall approach.This review introduces a novel and sustainable paradigm:the utilization of biomass-derived precursors as green reagents for the in-situ synthesis and simultaneous phosphorus-nitrogen(P-N)co-doping of ZnO nanoparticles.We critically analyze how the intrinsic biochemical composition of biomass,rich in P,N,and other heteroatoms,facilitates this one-pot,eco-friendly functionalization.This integrated strategy merges the performance enhancement offered by advanced co-doping,such as extended visible-light absorption and suppressed charge recombination,with the core principles of green chemistry and circular economy.It offers a dual benefit:creating highly effective photocatalysts for the degradation of persistent pollutants and valorizing abundant agricultural or biological waste streams.Our comprehensive evaluation goes beyond description to critically assess the underlying mechanisms,comparative efficacy,scalability challenges,and future research directions of this emerging field.This review underscores the unique contribution of biomass-mediated synthesis to advancing sustainable nanotechnology for environmental applications.
基金supported by National Natural Science Foundation of China(Nos.32271791,32171709 and 22475053)Hunan Provincial Natural Science Foundation of China(No.2024JJ7643)Natural Science Foundation of Shanghai(No.22ZR1404100).
文摘Hard carbon(HC)in sodium-ion batteries is searched by numerous investigations,which can offer the excellent performance of reversible Na^(+)insertion and extraction.The covalent heteroatom doping in HC is recently worth concentrating,which can dilate the interlayer spacing of graphite to adjust the electrochemical storage performance in carbon anodes.However,the reported doping strategies of the modified HC have only resulted in limited improvement,especially unobvious effects on tuning porous structure.In this study,tannin extract and K_(2)SO_(4) are respectively utilized as carbon source and sulfur source for the fabrication of HC,in which K_(2)SO_(4) can contribute to the heteroatom doping,and the pore forming as well.The tannin-derived sulfur-doped carbon anode shows the excellent cycle stability,achieving a high reversible capacity of 520.5 mAh/g at a current density of 100 mA/g.Even after 500 cycles at a current density of 3 A/g,a high specific capacity of 236.7 mAh/g and a capacity retention rate of 92.6%can be reserved.Compared with the initial carbon,the adsorption energy of Na^(+)is multifold times higher,whereas Na^(+)diffusion energy barriers manyfold decrease.Moreover,the full battery assembled with Na_(3)V_(2)(PO_(4))_(3)/tannin-based HC demonstrates a stable cycling performance.This work can manifest the potentiality of the tannin-based electrode as anode for a high-performance sodium-ion batteries(SIBs),which could especially offer an explanation of Na^(+)storage and solid-electrolyte interface(SEI)stability to the electrochemical performance.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.
基金support from the Key projects of scientific research projects of universities in Anhui Province(2024AH050360).
文摘MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper doping and carbon-based confinement.Residual carbon(RC),derived from acid-washed coal gasification fine slag(CGFS),serves as a conductive and porous framework for the directional growth of Cu-doped MnO_(2) nanowires(CMO@RC).The synergistic modulation of Cu-induced electronic structure tuning and carbon confinement induced mechanical/electrical stabilization significantly enhances Zn^(2+) transport and electrochemical performance.CMO@RC achieves a high capacity of 563 mA·h·g^(−1) at 0.1 A·g^(−1) and maintains 106%after 1000 cycles at 1 A·g^(−1).Kinetic analyses confirm the dual-path Zn^(2+) diffusion and accelerated reaction kinetics,while DFT calculations reveal that Cu doping enhances Mn 3d orbital hybridization and electron interaction with carbon,elevating the density of states near the Fermi level and reducing charge transfer barriers.Furthermore,pouch cell testing demonstrates outstanding flexibility and mechanical resilience.This study provides a cost-effective and scalable strategy for high-performance AZIBs,leveraging both experimental and theoretical validations.
基金supported by the National Natural Science Foundation of China(No.22209115,52472226,and U23A20573)the Key Research and Development Program of Shandong Province(No.2022CXGC010305)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2025A1515011809,2023B1515120022 and 2022B1515120001)Shenzhen Science and Technology Innovation Program(No.RCBS20231211090522040,KJZD20240903095610014,and KJZD20240903095712017)the High-Level Professional Team in Shenzhen(KQTD20210811090045006)。
文摘Seawater electrolysis is an appealing route toward sustainable hydrogen production,yet its practical deployment is hindered by severe chloride-induced corrosion and parasitic chlorine oxidation.Here,we report noble metal-doped NiV layered double hydroxides(LDHs)that integrate electronic modulation with a dual chloride confinement mechanism.Ir incorporation simultaneously establishes strong Ir-Cl coordination and dynamically regenerated VO_(4)^(3-)layers,producing an adaptive electrostatic shield that effectively suppresses chloride penetration.As a result,Ir-NiV LDH delivers nearly 100%oxygen evolution reaction selectivity and outstanding stability over2750 h at 500 mA cm^(-2).Meanwhile,Ru doping optimizes the hydrogen evolution pathway,enabling a low overpotential of 195 mV and>2350 h durability.When paired in a twso-electrode electrolyzer,the Ru-NiVLDH‖Ir-NiVLDH system exhibits industrial-level performance and unprecedented robustness in alkaline seawater.This dual chloride confinement concept provides a general framework for catalyst design in corrosive ionic environments,extending beyond seawater splitting toward other electrochemical energy conversion processes.
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金financially supported by the Natural Science Foundation of Shandong Province (No.ZR2022QE076)the National Natural Science Foundation of China (No.52202092)the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province of China (No.2023KJ104)。
文摘Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.
基金supported by the National Natural Science Foundation of China(Grant Nos.12274472,12494594,12494591,and 92165204)National Key Research and Development Program of China(Grant No.2022YFA1402802)+2 种基金Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)Guangdong Fundamental Research Center for Magnetoelectric Physics(Grant No.2024B0303390001)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401010)。
文摘We investigate the interplay between the pseudogap state and d-wave superconductivity in the two-dimensional doped Hubbard model by employing an eight-site cluster dynamical mean-field theory method.By tuning electron hopping parameters,the strong-coupling pseudogap in the two-dimensional Hubbard model can be either enhanced or suppressed in the doped Mott insulator regime.We find that in underdoped cases,the closing of pseudogap leads to a significant enhancement of superconductivity,indicating competition between the two in the underdoped regime.In contrast,at large dopings,suppressing the pseudogap is accompanied by a concurrent decrease in the superconducting transition temperature Tc,which can be attributed to a reduction in antiferromagnetic correlations behind both the pseudogap and superconductivity.We elucidate this evolving relationship between pseudogap and superconductivity across different doping regimes.
基金supported by the Jilin Provincial Scientific and Technological Development Program(No.20220101036JC)。
文摘By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.
基金financial supports from National Key R&D Program of China(Grant No.2022YFA1205100,2022YFA1404600)National Natural Science Foundation of China(Grant Nos.12192251,12334014,12474325,12134001,12304418,12474378,12274133,12174107,12174113,12274130)+2 种基金the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(No.2023nmc005).
文摘Miniaturized erbium-doped waveguide amplifiers attracted great interests in recent decades due to their high gain-efficiency and function-scalability in the telecom C-band.In this work,an erbium-doped thin film lithium niobate waveguide amplifier achieving>10 dB off-chip(fiber-to-fiber)net gain and>20 mW fiber-output amplified power is demonstrated,thanks to the low-propagation-loss waveguides and robust waveguide edge-couplers prepared by the photolithography assisted chemomechanical etching technique.Systematic investigation on the fabricated waveguide amplifiers reveals remarkable optical gain around the peak wavelength of 1532 nm as well as the low fiber-coupling loss of-1.2 dB/facet.A fiber Bragg-grating based waveguide laser is further demonstrated using the fabricated waveguide amplifier as the external gain chip,which generates>2 mW off-chip power continuous-wave lasing around the gain peak at 1532 nm.The unambiguous demonstration of fiber-to-fiber net gain of the erbium-doped thinfilm lithium niobate(TFLN)waveguide amplifier as well as its external gain chip application will benefit diverse fields demanding scalable gain elements with highspeed tunability.
基金National Natural Science Foundation of China(No.22272149,22062025)Yunnan University’s Research Innovation Fund for Graduate Students(No.KC-23234085)+1 种基金Workstation of Academician Chen Jing of Yunnan Province(No.202105AF150012)Free Exploration Fund for Academician(No.202405AA350001)。
文摘Electrocatalytic conversion of renewable biomass is emerging as a promising route for sustainable chemical production;hence it urgently calls for developing efficient electrocatalysts with low potentials and high current densities.Herein,a Pr-doped Co(OH)_(2)hexagonal sheet(Pr/Co=1/9,in mole)is synthesized by electrodeposition as highly performant catalyst for 5-hydroxymethylfurfural(HMF)oxidation reaction(HMFOR)to produce 2,5-furandicarboxylic acid(FDCA).This novel and low-cost catalyst possesses a rather low onset potential of 1.05 V(vs.RHE)and requires only 1.10 V(vs.RHE)to reach a current density of 10 mA cm^(-2)for HMFOR,significantly outperforming Co(OH)_(2)benchmark(i.e.,210 mV higher to reach10 m A cm^(-2)).The origin of Pr promotion effect as well as the evolution of CoOOH catalytic sites and HMFOR process has been deeply elucidated by physical characterizations,kinetic experiments,in situ electrochemical techniques,and theoretical calculations.The unique Pr-ameliorated CoOOH active centers enable 100%conversion of HMF,99.6%selectivity of FDCA,and 99.7%Faraday efficiency,with a superior cycling durability toward HMFOR.This can be one of the most outstanding results for Co-based HMFOR catalysts to date in the literature.Thereby this work can help open up new horizons for constructing novel and efficient Co-based electrocatalysts by the utilization of lanthanide elements.
基金supported by the Guangdong Basic and Applied Basic Research Foundation (No.2023A1515010093)the Shenzhen Fundamental Research Program (Stable Support Plan Program)(Nos.JCYJ20220809170611004, 20231121110828001 and 20231121113641002)the National Taipei University of Technology-Shenzhen University Joint Research Program (No.2024001)。
文摘In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.
基金supported by the National Natural Science Foundation of China (Grant No.22063010)the Natural Science Foundation of Shaanxi Province (Grant No.2022QFY07-05)Yan'an Science and Technology Plan Project (Grants No.2022SLJBZ-002, 2023-CYL-193)。
文摘We used the natural product chamomile as a carbon source to synthesize praseodymium(Pr) and nitrogen(N) co-doped biomass carbon dots(Pr/N-BCDs) with remarkable luminescence properties by one-step hydrothermal method.Compared with single N-doped BCDs(N-BCDs) and Pr-doped BCDs(Pr-BCDs),Pr/N-BCDs not only showed better fluorescence properties and stability but also achieved a significant increase in quantum yield of 12%.More importantly,under certain conditions,Pr/N-BCDs and 2,4-dinitrophenylhydrazide(2,4-DNPH) had significant fluorescence internal filtration effect(IFE) and dynamic quenching effect,and in the concentration range of0.50-20 μmol·L^(-1),the concentration of 2,4-DNPH had a good linear relationship with the fluorescence quenching signal,and the detection limit was as low as 2.1 nmol·L^(-1).
基金the financial support from Sichuan Science and Technology Program(No.2023NSFSC0847)Scientific Research and Innovation Team Program of Sichuan University of Science and Technology(No.SUSE652A003)+3 种基金Talent Introduction Project of Sichuan University of Science and Engineering(No.2021RC03)Talent Introduction Project of Sichuan University of Science and Engineering(No.2021RC05)the Undergraduate Training Program for Innovation and Entrepreneurship(No.CX2024042)The Innovation Fund of Postgraduate,Sichuan University of Science&Engineering(No.Y2024094)。
文摘N-doped graphite carbon sphere coated cobalt nanoparticle catalyst(Co@C-N-900),prepared by solvothermal-calcination method,is applied to activate peroxymonosulfate(PMS)for bisphenol A(BPA)elimination.The outcomes demonstrate that the Co@C-N-900 could effectively activate PMS,thereby causing efficient removal of BPA in water.In addition,the Co@C-N-900/PMS system also has the advantages of low metal leaching,applicability in high salinity environments,good selectivity and stability.Further investigations using electron paramagnetic resonance,chronoamperometry,and quenching experiments demonstrated that the Co@C-N-900/PMS system is a typical non-radical route with singlet oxygen(^(1)O_(2))as the main reactive oxygen species(ROS).Density functional theory calculations(DFT)indicate that N-doping can effectively regulate the charge distribution on the catalyst surface,generating acidic/alkaline sites favorable for PMS adsorption and activation.Furthermore,it also can enhance the interaction and charge transfer capacity between the Co@C-N-900 and PMS.Lastly,LC-QTOF-MS/MS analysis revealed two possible BPA degradation pathways:(1)^(1)O_(2)attacked the isopropyl group in BPA between the two phenyl groups,causingβ-scission to occur.(2)Following the oxidation of the hydroxyl group in the aromatic ring of BPA,^(1)O_(2)could cause furtherβ-scission.The prepared Co@C-N-900 catalyst is a very promising catalyst,which would offer a workable remedy for treating water pollution.
