Despite being a promising photoanode material for water splitting,WO_(3) has low conductivity,high onset potential,and sluggish water oxidation kinetics.In this study,we designed Ti-doped WO_(3) nanoplate arrays on fl...Despite being a promising photoanode material for water splitting,WO_(3) has low conductivity,high onset potential,and sluggish water oxidation kinetics.In this study,we designed Ti-doped WO_(3) nanoplate arrays on fluoride-doped tin oxide by a seed-free hydrothermal method,and the effects of doping on the photoelectrochemical performance were investigated.The optimal Ti-doped WO_(3) electrode achieved a photocurrent density of 0.53 mA/cm^(2) at 0.6 V(vs Ag/AgCl),110%higher than that of pure WO_(3) nanoplate arrays.Moreover,a significant cathodic shift in the onset potential was observed after doping.X-ray photoelectron spectroscopy valence band and ultraviolet–visible spectra revealed that the band positions of Ti-doped WO_(3) photoanodes moved upward,yielding a lower onset potential.Furthermore,electrochemical impedance spectroscopy measurements revealed that the conductivities of the WO_(3) photoanodes improved after doping,because of the rapid separation of photo-generated charge carriers.Thus,we report a new design route toward efficient and low-cost photoanodes for photoelectrochemical applications.展开更多
The irreversible anionic redox reaction and oxygen release of Li-rich layered oxide cathodes seriously hinder their commercial application.Here,a synergistic modification strategy of surface dielectric coating(TiNb_(2...The irreversible anionic redox reaction and oxygen release of Li-rich layered oxide cathodes seriously hinder their commercial application.Here,a synergistic modification strategy of surface dielectric coating(TiNb_(2)O_(7))and bulk phase Ti doping is proposed in this paper.TiNb_(2)O_(7),as a dielectric oxide,can generate a reversed electric field during charging to block the migration path of anions inside the material.In addition,the unique three-dimensional Li+diffusion channels of TiNb_(2)O_(7)can improve the lithium-ion diffusion kinetics.The results show that the synergistic modification strategy fundamentally inhibits oxygen loss and enhances the reversibility of anion redox,while constructing a uniform and stable CEI interface.The co-modification strategy effectively improves the electrochemical performance of the materials.The modified sample can maintain a high capacity of 175.1 mA h g^(−1)after 500 cycles at 1 C.This work provides new insights to improve the oxygen loss problem of Li-rich layered oxide cathodes.展开更多
In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable struc...In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable structure with expanded crystal lattice distance which improves Li ion diffusion kinetics.The dopants have suppressed the growth of primary particles,formed a coating on the surface,and promoted the elongated morphology.Moreover,the mechanical strength of these particles has increased,as confirmed by the nanoindentation test,which can help suppress particle cracking.The detrimental H2-H3 phase transition has been postponed by 90 mV allowing the cathode to operate at a higher voltage.A better cycling stability over 100 cycles with 69%capacity retention has been observed.We believe this work points out a way to improve the cycling performance,Coulombic efficiency and capacity retention in Ni-rich cathodes.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
Due to the sodium abundance and availability,sodium-ion batteries(SIBs)have the potential to meet the worldwide growing demand of electrical energy storage.P2-type sodium transition-metal layer oxides with a high ener...Due to the sodium abundance and availability,sodium-ion batteries(SIBs)have the potential to meet the worldwide growing demand of electrical energy storage.P2-type sodium transition-metal layer oxides with a high energy density are considered as the most promising cathode materials for SIBs.We present here a detailed study of the enhanced rate capability and cyclic stability of the Ti-doped Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)cathode material.The combined analysis of ex-situ X-ray absorption fine structure(XAFS)spectroscopy,aberration-corrected high resolution transmission electron microscopy(AB-HRTEM)and X-ray diffraction(XRD)show that the strong Ti–O bond in the transition metal layers stabilizes the local structure,destroy the Na+-vacancy ordering and arrest the irreversible multiphase transformation that occurs during the intercalation/deintercalation process.Actually,Na_(0.67)Ni_(0.33)Mn_(0.52)Ti_(0.15)O_(2)exhibits a reversible capacity of 89.6 mA h g^(-1)even at 5 C,an excellent cyclability with 88.78%capacity retention after 200 cycles at 0.5 C.This study provides a better understanding in optimization of the design of high-energy cathode materials based on titanium doped layered oxides for SIBs.展开更多
Aqueous zinc-ion batteries(AZIBs)have become a hotspot for electrochemical energy storage owing to the high safety,low cost,environmental friendliness,and favorable rate performance.However,the serious dissolution of ...Aqueous zinc-ion batteries(AZIBs)have become a hotspot for electrochemical energy storage owing to the high safety,low cost,environmental friendliness,and favorable rate performance.However,the serious dissolution of cathode materials in aqueous electrolytes would lead to poor cyclability,which should be addressed before commercialization.Herein,we designed a Ti-doped V_(2)O_(5) with yolk-shell microspherical structure for AZIBs.The Ti doping stabilizes the crystal structure and relieves the dissolution of V_(2)O_(5) in aqueous ZnSO_(4) electrolyte.The optimized sample,Ti_(0.2)V_(1.8)O_(4.9),delivers a high capacity(355 mAh/g at 0.05 A/g)as well as good capacity retention(89%after 2500 cycles at 1.0 A/g).This work provides an effective strategy to mitigate the dissolution of cathode material in aqueous ZnSO_(4) electrolyte for cyclability enhancement.展开更多
The effect of Ti addition on microstructures and magnetic properties of B-lean(Pr,Nd)_(31.1)Fe_(67.1-x)(CoCuGa)_(1.4)Ti_(x)B_(0.9)(wt%,x=0.0,0.1,0.2,0.3,0.4)sintered magnets were investigated.The remanence Bris slight...The effect of Ti addition on microstructures and magnetic properties of B-lean(Pr,Nd)_(31.1)Fe_(67.1-x)(CoCuGa)_(1.4)Ti_(x)B_(0.9)(wt%,x=0.0,0.1,0.2,0.3,0.4)sintered magnets were investigated.The remanence Bris slightly reduced due to the deteriorated orientation degree and the diminished volume fraction of main phase caused by the existence of rod-shaped Ti-B-rich phase.However,the HcJobviously increases from1145 kA/m for x=0.0 sample to 1515 kA/m for x=0.2 sample.The results demonstrate that the increments of coercivity for x=0.2 and x=0.0 samples after post-sinter annealing(PSA)are 62.9%and 20.6%,respectively.Rod-shaped Ti-B-rich phase forms after Ti doping,which leads to the existence of6:13:1 type RE-Fe-(Cu,Ga)phase with high Fe content at triple junctions.This is beneficial to the formation of continuous thin grain boundaries with low Fe content,which can weaken the exchange coupling interaction between adjacent grains,leading to the improved coercivity.展开更多
Density functional theory （DFT） calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 （002） surfaces. When Ti is doped into the WO3 surface, two substitution models are considere...Density functional theory （DFT） calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 （002） surfaces. When Ti is doped into the WO3 surface, two substitution models are considered： substitution of Ti for W6c and substitution of Ti for Wsc. The results reveal that substitution of Ti for 5-fold W forms a stable doping structure, and doping induces some new electronic states in the band gap, which may lead to changes in the surface properties. Four top adsorption models of NO2 on pure and Ti-doped WO3 （002） surfaces are investigated： adsorptions on 5-fold W （Ti）, on 6-fold W, on bridging oxygen, and on plane oxygen. The most stable and likely NO2 adsorption structures are both N-end oriented to the surface bridge oxygen Olc site. By comparing the adsorption energy and the electronic population, it is found that Ti doping can enhance the adsorption of NO2, which theoretically proves the experimental observation that Ti doping can greatly increase the WO3 gas sensor sensitivity to NO2 gas.展开更多
Na-based layered iron-manganese oxide Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) containing only low-cost elements is a promising cathode for Na-ion batteries used in large-scale energy storage systems.However,the poor cycle stab...Na-based layered iron-manganese oxide Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) containing only low-cost elements is a promising cathode for Na-ion batteries used in large-scale energy storage systems.However,the poor cycle stability restricts its practical application.The capacity decay of Na_(0.67)Fe_(0.6)Mn_(0.5)O_(2) mainly originates from the irreversible anionic redox reaction charge compensation due to the high-level hybridization between oxygen and iron.Herein,we rationally design a surface Ti doping strategy to tune the anionic redox reaction activity of Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) and improve its Na-storage properties.The doped Ti ions not only enlarge the Na migration spacing layer but also improve the structure stability thanks to the strong Ti-O bond.More importantly,the d0-shell electronic structure of Ti^(4+) can suppress the charge transfer from the oxidized anions to cations,thus reducing the anionic redox reaction activity and enhancing the reversibility of charge compensation.The modified Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) cathode shows a reversible capacity of 198 mA h g^(-1) and an increased capacity retention from 15% to 73% after about1 month of cycling.Meanwhile,a superior Na-ion diffusion kinetics and rate capability are also observed.This work advances the commercialization process of Na-based layered iron-manganese oxide cathodes;on the other hand,the proposed modification strategy paves the way for the design of high-performance electrode materials relying on anionic redox reactions.展开更多
For Ti-doped hematite photoanodes, high temperature annealing drastically increases the water oxidation plateau photocurrent, but also induces an anodic shift of onset potential by about 100 m V, thus hindering the pe...For Ti-doped hematite photoanodes, high temperature annealing drastically increases the water oxidation plateau photocurrent, but also induces an anodic shift of onset potential by about 100 m V, thus hindering the performance under low applied bias. To the best of our knowledge, the effects of high temperature annealing on the onset potential have been rarely studied. Herein, both X-ray photoelectron spectroscopy（XPS） measurements and theoretical calculations indicated that the increase of surface Ti/Fe atomic ratio after high temperature annealing decreased the adsorption capacity of hydroxide ions on the hematite surface. Subsequently, the flatband potential（i.e., the theoretical onset potential） of Ti doped hematite photoanodes positively shifted, which was supported by the Mott-Schottky measurements.展开更多
The photoelectrochemical(PEC)water oxidation reaction on hematite(α-Fe₂O₃)photoanodes has certain limitations,especially poor conductivity and rapid carrier recombination.Thus,to address these issues,uniform Ti dopin...The photoelectrochemical(PEC)water oxidation reaction on hematite(α-Fe₂O₃)photoanodes has certain limitations,especially poor conductivity and rapid carrier recombination.Thus,to address these issues,uniform Ti doping and gradient Ge doping were performed to construct Ti–Ge co-doped hematite(Ti–Ge:Fe₂O₃).A series of characterization tests showed that uniform Ti doping increased carrier concentration and conductivity,while gradient Ge doping improved charge separation efficiency.Meanwhile,Ti–Ge co-doping in hematite formed a gradient energy band structure,which played a role in improving the charge separation efficiency.The co-doping of other metal elements with Ti was also carried out,which showed significant effects in improving PEC performance.This suggested that Ti:M(M=metal elements)co-doping in hematite to improve its PEC performance is universal.In addition,when the NiFeOOH co-catalyst was loaded on Ti–Ge:Fe₂O₃,the onset potential negatively shifted by 150 mV and the photocurrent density significantly improved,which was about 9.7 times higher than that of bare Fe₂O₃.This work provides a novel strategy for improving the PEC performance of hematite via co-doping engineering.展开更多
A different approach to synthesize visible‐light‐active sulfur(S)‐doped reduced titania(S‐TiO2‐x)using thiourea dioxide as both the S source and reductant was developed.The structure,morphology,and optical and el...A different approach to synthesize visible‐light‐active sulfur(S)‐doped reduced titania(S‐TiO2‐x)using thiourea dioxide as both the S source and reductant was developed.The structure,morphology,and optical and electronic properties of the as‐prepared S‐TiO2‐x samples were examined by multiple techniques,such as X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy,ultraviolet‐visible diffuse reflectance spectroscopy,Brunauer‐Emmett‐Teller and photocurrent measurements,and electrochemical impedance spectroscopy.The photocatalytic activity of S‐TiO2‐x was evaluated by photodegradation of organic Rhodamine B under visible‐light irradiation.The degradation rate of Rhodamine B by S‐TiO2‐x obtained by calcination was about31,2.5,and3.6times higher than those of pure TiO2,pristine TiO2‐x,and S‐doped TiO2,respectively.In addition,the as‐prepared S‐TiO2‐x exhibited long‐term stable photocatalytic performance in the degradation of Rhodamine B under visible‐light illumination.This report reveals a new approach to prepare stable and highly efficient solar light‐driven photocatalysts for water purification.展开更多
Ti^（3＋） self-doped anatase three-dimensional（3D） TiO_2 hollow nanoboxes were synthesized via a topological transformation process involving template participation by a facile one-pot hydrothermal treatment with a...Ti^（3＋） self-doped anatase three-dimensional（3D） TiO_2 hollow nanoboxes were synthesized via a topological transformation process involving template participation by a facile one-pot hydrothermal treatment with an ethanol solution of zinc powder and TiOF_2. It is worth noting that the 3D TiO_2 hollow nanoboxes are assembled from six single-crystal nanosheets and have dominant exposure of the {001} facets. It is found from EPR spectra that adding zinc powder is an environment-friendly and effective strategy to introduce Ti^（3＋） and oxygen vacancy（Ov） into the bulk of 3D hollow nanoboxes rather than the surface, which is responsible for their enhanced visible photocatalytic properties.The photocatalytic activity was evaluated by measuring the formation rate of hydroxide free radicals using 7-hydroxycoumarin as a probe. The sample prepared with zinc/TiOF_2 mass ratio of0.25 exhibited the highest RhB photodegradation activity under visible-light irradiation with a degradation rate of 96%, which is 4.0-times higher than that of pure TiO_2. The results suggest a novel approach to construct in-situ 3D hierarchical TiO_2 hollow nanoboxes doped with Ti^（3＋） and Ov without introducing any impurity elements for superior visible-light photocatalytic activity.展开更多
Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of t...Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.展开更多
A sintered Ti13Cus7 target was sputtered by reactive direct current （DC） magnetron sputtering with a gas mixture of argon/nitrogen for different sputtering powers. Titanium-coppernitrogen thin films were deposited o...A sintered Ti13Cus7 target was sputtered by reactive direct current （DC） magnetron sputtering with a gas mixture of argon/nitrogen for different sputtering powers. Titanium-coppernitrogen thin films were deposited on Si （111）, glass slide and potassium bromide （KBr） substrates. Phase analysis and structural properties of titanium-copper-nitrogen thin films were studied by X-ray diffraction （XRD）. The chemical bonding was characterized by Fourier transform infrared （FTIR） spectroscopy. The results from XRD show that the observed phases are nano-crystallite cubic anti rhenium oxide （anti ReO3） structures of titanium doped Cu3N （Ti：Cu3N） and nanocrystallite face centered cubic （fcc） structures of copper. Scanning electron microscopy and energy dispersive X-ray spectroscopy （SEM/EDX） were used to determine the film morphology and atomic titanium/copper ratio, respectively. The films possess continuous and agglomerated structure with an atomic titanium/copper ratio （-0.07） below that of the original target （- 0.15）. The transmittance spectra of the composite films were measured in the range of 360 nm to 1100 nm. Film thickness, refractive index and extinction coefficient were extracted from the measured transmittance using a reverse engineering method. In the visible range, the higher absorption coefficient of the films prepared at lower sputtering power indicates more nitrification in comparison to those prepared at higher sputtering power. This is consistent with the formation of larger Ti：Cu3N crystallites at lower sputtering power. The deposition rate vs. sputtering power shows an abrupt transition from metallic mode to poisoned mode. A complicated behavior of the films＇ resistivity upon sputtering power is shown.展开更多
P2-type Na-NiMn oxides have garnered significant attention for sodium-ion batteries owing to their excellent rate capability.However,they are adversely affected by the harmful P2-O2 phase transitions,which cause subst...P2-type Na-NiMn oxides have garnered significant attention for sodium-ion batteries owing to their excellent rate capability.However,they are adversely affected by the harmful P2-O2 phase transitions,which cause substantial capacity degradation and poor cycling performance.In this work,a unique P2(84%)/O3(16%)biphasic layered oxide,Na_(0.76)Ni_(0.22)Mg_(0.11)Mn_(0.57)Ti_(0.1)O_(2)(NNMMT),is successfully designed and synthesized by a Mg/Ti co-doping strategy.The doping of Mg and Ti can form stable O-TM-O bonds,while the biphasic structure generates distinctive interlocked interfaces at the boundaries.The harmful phase transition caused by the interlayer slip and structural strain is well suppressed under the synergistic effect of these two factors.As a result,NNMMT demonstrates exceptional capacity and cycling stability(reversible capacity of 109.8 mAh g^(-1) at 1 C and capacity retention of 97.35%after 100 cycles).Meanwhile,the higher proportion of the P2 phase enables NNMMT to maintain excellent rate capability(initial discharge capacity of 88.9 mAh g^(-1) at 5 C).Additionally,ex situ X-ray diffraction analyses before and after cycling demonstrated a significant suppression of the detrimental P2-O2 phase transition in NNMMT during the charge-discharge process,leading to a notable enhancement in structural stability.This work provides an innovative and efficient strategy for designing highly stable layered oxide cathodes.展开更多
We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump....We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.展开更多
n-Type polycrystalline SnSe with Ti,Pb co-doping was synthesized by combining mechanical alloying(MA)with spark plasma sintering(SPS).It is revealed that Ti is an effective cationic dopant to convert SnSe from a p-typ...n-Type polycrystalline SnSe with Ti,Pb co-doping was synthesized by combining mechanical alloying(MA)with spark plasma sintering(SPS).It is revealed that Ti is an effective cationic dopant to convert SnSe from a p-type to an n-type semiconductor,and the thermoelectric performance of the Ti-doped SnSe is also improved in comparison with the pristine sample due to an enhanced power factor.Furthermore,after further Pb doping,an obviously improved electrical conductivity together with a moderate Seebeck coefficient can be achieved,which results in an improvement of the power factor with a maximum value of 300μW m^(−1) K^(−2) at 773 K.Meanwhile,the lattice thermal conductivity is significantly reduced because of the enhanced phonon scattering owing to the mass and strain fluctuations.Therefore,a final ZT value of 0.4 was obtained for composition of Sn_(0.74)Pb_(0.20)Ti_(0.06)Se at 773 K,which is a conservative value for n-type SnSe with cationic dopant prepared by the simple preparation process of MA and SPS.展开更多
The solar-driven selective oxidation of amines to imines has attracted widespread attention due to its green and non-polluting nature,as well as its high selectivity.In this study,a unique S-scheme BiOCl/UiO-66(Ce/Ti)...The solar-driven selective oxidation of amines to imines has attracted widespread attention due to its green and non-polluting nature,as well as its high selectivity.In this study,a unique S-scheme BiOCl/UiO-66(Ce/Ti)heterojunction was first constructed as an organic aerobic photocatalyst.Under visible light irradiation with water as the sole solvent,the yield of the imine reached 98%.The S-scheme charge transfer mechanism was verified through in situ X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements,revealing the source of excellent photocatalytic activity.Additionally,the synergistic effect of the interface microenvironment generated by the interaction between OVs and Ce-Ti was found to play a significant role in the photocatalytic oxidation process.This work emphasizes the importance of designing a heterojunction interface microenvironment(IME)for achieving efficient photocatalytic selective oxidation of amines.展开更多
Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3...Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3)thin film remains a challenging task.In this work,titanium(Ti)doping effectively modifies the electronic band structure in Sb_(2)Te_(3),optimizing both carrier transport and phonon transport performance.Ti-doping optimizes carrier concentration and resulting in an increase in electrical conductivity from 1420.0 S/cm to 1694.8 S/cm at 300 K.Additionally,Ti doping modulates the balance between the effective mass of charge carriers and carrier concentration,increasing Seebeck coefficient from 106.0μV/K to 114.8μV/K.Both enhancements lead to a peak power factor of 20.9μW·cm^(−1)·K^(−2).Moreover,Ti-induced vibrational modes have reduced the lattice thermal conductivity from 0.62 W·m^(−1)·K^(−1)to 0.22 W·m^(−1)·K^(−1),improving zT from 0.33 to 0.52 at 300 K.The films exhibit excellent flexibility,with an ultralow resistance change ratio(ΔR/R_(0))of less than 7%after 1000 cycles at a 6 mm bending radius.The device achieves a maximum output power of 178.8 nW with a temperature gradient of 30 K in agreement with the finite element analysis,indicating significant potential for wearable electronics.展开更多
基金Project(Qian Jiao He KY Zi [2021]257) supported provided by the Natural Science Research Project of Education Department of Guizhou Province,ChinaProject(GZSQCC2019003) supported by the High-level Innovative Talent Cultivation Project of Guizhou Province,ChinaProjects(GZLGXM-01,GZLGXM-08) supported by the Academic New Seedling Cultivation and Innovation Exploration Project of Guizhou Institute of Technology,China。
文摘Despite being a promising photoanode material for water splitting,WO_(3) has low conductivity,high onset potential,and sluggish water oxidation kinetics.In this study,we designed Ti-doped WO_(3) nanoplate arrays on fluoride-doped tin oxide by a seed-free hydrothermal method,and the effects of doping on the photoelectrochemical performance were investigated.The optimal Ti-doped WO_(3) electrode achieved a photocurrent density of 0.53 mA/cm^(2) at 0.6 V(vs Ag/AgCl),110%higher than that of pure WO_(3) nanoplate arrays.Moreover,a significant cathodic shift in the onset potential was observed after doping.X-ray photoelectron spectroscopy valence band and ultraviolet–visible spectra revealed that the band positions of Ti-doped WO_(3) photoanodes moved upward,yielding a lower onset potential.Furthermore,electrochemical impedance spectroscopy measurements revealed that the conductivities of the WO_(3) photoanodes improved after doping,because of the rapid separation of photo-generated charge carriers.Thus,we report a new design route toward efficient and low-cost photoanodes for photoelectrochemical applications.
基金supported by the National Natural Science Foundation of China(51972023).
文摘The irreversible anionic redox reaction and oxygen release of Li-rich layered oxide cathodes seriously hinder their commercial application.Here,a synergistic modification strategy of surface dielectric coating(TiNb_(2)O_(7))and bulk phase Ti doping is proposed in this paper.TiNb_(2)O_(7),as a dielectric oxide,can generate a reversed electric field during charging to block the migration path of anions inside the material.In addition,the unique three-dimensional Li+diffusion channels of TiNb_(2)O_(7)can improve the lithium-ion diffusion kinetics.The results show that the synergistic modification strategy fundamentally inhibits oxygen loss and enhances the reversibility of anion redox,while constructing a uniform and stable CEI interface.The co-modification strategy effectively improves the electrochemical performance of the materials.The modified sample can maintain a high capacity of 175.1 mA h g^(−1)after 500 cycles at 1 C.This work provides new insights to improve the oxygen loss problem of Li-rich layered oxide cathodes.
基金support from Queensland University of Technology,Brisbane,Queensland,Australiafinancial support from ARC Discovery Project(DP210103266).
文摘In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable structure with expanded crystal lattice distance which improves Li ion diffusion kinetics.The dopants have suppressed the growth of primary particles,formed a coating on the surface,and promoted the elongated morphology.Moreover,the mechanical strength of these particles has increased,as confirmed by the nanoindentation test,which can help suppress particle cracking.The detrimental H2-H3 phase transition has been postponed by 90 mV allowing the cathode to operate at a higher voltage.A better cycling stability over 100 cycles with 69%capacity retention has been observed.We believe this work points out a way to improve the cycling performance,Coulombic efficiency and capacity retention in Ni-rich cathodes.
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the National Natural Science Foundation of China(No.11705015,U1832147)the Science and Technology Plan Project of Suzhou(Nos.SYG201738 and SZS201710)。
文摘Due to the sodium abundance and availability,sodium-ion batteries(SIBs)have the potential to meet the worldwide growing demand of electrical energy storage.P2-type sodium transition-metal layer oxides with a high energy density are considered as the most promising cathode materials for SIBs.We present here a detailed study of the enhanced rate capability and cyclic stability of the Ti-doped Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2)cathode material.The combined analysis of ex-situ X-ray absorption fine structure(XAFS)spectroscopy,aberration-corrected high resolution transmission electron microscopy(AB-HRTEM)and X-ray diffraction(XRD)show that the strong Ti–O bond in the transition metal layers stabilizes the local structure,destroy the Na+-vacancy ordering and arrest the irreversible multiphase transformation that occurs during the intercalation/deintercalation process.Actually,Na_(0.67)Ni_(0.33)Mn_(0.52)Ti_(0.15)O_(2)exhibits a reversible capacity of 89.6 mA h g^(-1)even at 5 C,an excellent cyclability with 88.78%capacity retention after 200 cycles at 0.5 C.This study provides a better understanding in optimization of the design of high-energy cathode materials based on titanium doped layered oxides for SIBs.
基金the National Natural Science Foundation of China(No.52102299)the Independent Innovation Project of Hubei Longzhong Laboratory(No.2022ZZ-18)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110059)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(No.XHT2020-003).
文摘Aqueous zinc-ion batteries(AZIBs)have become a hotspot for electrochemical energy storage owing to the high safety,low cost,environmental friendliness,and favorable rate performance.However,the serious dissolution of cathode materials in aqueous electrolytes would lead to poor cyclability,which should be addressed before commercialization.Herein,we designed a Ti-doped V_(2)O_(5) with yolk-shell microspherical structure for AZIBs.The Ti doping stabilizes the crystal structure and relieves the dissolution of V_(2)O_(5) in aqueous ZnSO_(4) electrolyte.The optimized sample,Ti_(0.2)V_(1.8)O_(4.9),delivers a high capacity(355 mAh/g at 0.05 A/g)as well as good capacity retention(89%after 2500 cycles at 1.0 A/g).This work provides an effective strategy to mitigate the dissolution of cathode material in aqueous ZnSO_(4) electrolyte for cyclability enhancement.
基金supported by the National Natural Science Foundation of China(52061015,52371188)Young Talents Program of Jiangxi Provincial Major Discipline Academic and Technical Leaders Training Program(20212BCJ23008)+2 种基金Jiangxi Provincial Natural Science Foundation(20212BAB214018)Technology Program of Fujian Province(2021T3063)Jiangxi Province Key Laboratory of Magnetic Metallic Materials and Devices(2024SSY05061)。
文摘The effect of Ti addition on microstructures and magnetic properties of B-lean(Pr,Nd)_(31.1)Fe_(67.1-x)(CoCuGa)_(1.4)Ti_(x)B_(0.9)(wt%,x=0.0,0.1,0.2,0.3,0.4)sintered magnets were investigated.The remanence Bris slightly reduced due to the deteriorated orientation degree and the diminished volume fraction of main phase caused by the existence of rod-shaped Ti-B-rich phase.However,the HcJobviously increases from1145 kA/m for x=0.0 sample to 1515 kA/m for x=0.2 sample.The results demonstrate that the increments of coercivity for x=0.2 and x=0.0 samples after post-sinter annealing(PSA)are 62.9%and 20.6%,respectively.Rod-shaped Ti-B-rich phase forms after Ti doping,which leads to the existence of6:13:1 type RE-Fe-(Cu,Ga)phase with high Fe content at triple junctions.This is beneficial to the formation of continuous thin grain boundaries with low Fe content,which can weaken the exchange coupling interaction between adjacent grains,leading to the improved coercivity.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60771019 and 60801018)Tianjin Key Research Program of Application Foundation and Advanced Technology, China (Grant No. 11JCZDJC15300)+1 种基金Tianjin Natural Science Foundation, China (Grant No. 09JCYBJC01100)the New Teacher Foundation of the Ministry of Education, China(Grant No. 200800561109)
文摘Density functional theory （DFT） calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 （002） surfaces. When Ti is doped into the WO3 surface, two substitution models are considered： substitution of Ti for W6c and substitution of Ti for Wsc. The results reveal that substitution of Ti for 5-fold W forms a stable doping structure, and doping induces some new electronic states in the band gap, which may lead to changes in the surface properties. Four top adsorption models of NO2 on pure and Ti-doped WO3 （002） surfaces are investigated： adsorptions on 5-fold W （Ti）, on 6-fold W, on bridging oxygen, and on plane oxygen. The most stable and likely NO2 adsorption structures are both N-end oriented to the surface bridge oxygen Olc site. By comparing the adsorption energy and the electronic population, it is found that Ti doping can enhance the adsorption of NO2, which theoretically proves the experimental observation that Ti doping can greatly increase the WO3 gas sensor sensitivity to NO2 gas.
基金supported by the National Natural Science Foundation of China (Grant No. 12105197)the Science Center of the National Science Foundation of China (Grant No. 52088101)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Scientific Instrument Developing Project of the Chinese Academy of Sciences (Grant ZDKYYQ20170001)。
文摘Na-based layered iron-manganese oxide Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) containing only low-cost elements is a promising cathode for Na-ion batteries used in large-scale energy storage systems.However,the poor cycle stability restricts its practical application.The capacity decay of Na_(0.67)Fe_(0.6)Mn_(0.5)O_(2) mainly originates from the irreversible anionic redox reaction charge compensation due to the high-level hybridization between oxygen and iron.Herein,we rationally design a surface Ti doping strategy to tune the anionic redox reaction activity of Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) and improve its Na-storage properties.The doped Ti ions not only enlarge the Na migration spacing layer but also improve the structure stability thanks to the strong Ti-O bond.More importantly,the d0-shell electronic structure of Ti^(4+) can suppress the charge transfer from the oxidized anions to cations,thus reducing the anionic redox reaction activity and enhancing the reversibility of charge compensation.The modified Na_(0.67)Fe_(0.5)Mn_(0.5)O_(2) cathode shows a reversible capacity of 198 mA h g^(-1) and an increased capacity retention from 15% to 73% after about1 month of cycling.Meanwhile,a superior Na-ion diffusion kinetics and rate capability are also observed.This work advances the commercialization process of Na-based layered iron-manganese oxide cathodes;on the other hand,the proposed modification strategy paves the way for the design of high-performance electrode materials relying on anionic redox reactions.
基金supported by the National Natural Science Foundation of China (Nos. 21473090, U1663228)
文摘For Ti-doped hematite photoanodes, high temperature annealing drastically increases the water oxidation plateau photocurrent, but also induces an anodic shift of onset potential by about 100 m V, thus hindering the performance under low applied bias. To the best of our knowledge, the effects of high temperature annealing on the onset potential have been rarely studied. Herein, both X-ray photoelectron spectroscopy（XPS） measurements and theoretical calculations indicated that the increase of surface Ti/Fe atomic ratio after high temperature annealing decreased the adsorption capacity of hydroxide ions on the hematite surface. Subsequently, the flatband potential（i.e., the theoretical onset potential） of Ti doped hematite photoanodes positively shifted, which was supported by the Mott-Schottky measurements.
基金supported by the National Natural Science Foundation of China(Grant No.22472071,22075119)the Natural Science Foundation of Gansu Province,China(21JR7RA440)Youth and Middle-aged Fundation of Qinghai Normal University(2024QZR05).
文摘The photoelectrochemical(PEC)water oxidation reaction on hematite(α-Fe₂O₃)photoanodes has certain limitations,especially poor conductivity and rapid carrier recombination.Thus,to address these issues,uniform Ti doping and gradient Ge doping were performed to construct Ti–Ge co-doped hematite(Ti–Ge:Fe₂O₃).A series of characterization tests showed that uniform Ti doping increased carrier concentration and conductivity,while gradient Ge doping improved charge separation efficiency.Meanwhile,Ti–Ge co-doping in hematite formed a gradient energy band structure,which played a role in improving the charge separation efficiency.The co-doping of other metal elements with Ti was also carried out,which showed significant effects in improving PEC performance.This suggested that Ti:M(M=metal elements)co-doping in hematite to improve its PEC performance is universal.In addition,when the NiFeOOH co-catalyst was loaded on Ti–Ge:Fe₂O₃,the onset potential negatively shifted by 150 mV and the photocurrent density significantly improved,which was about 9.7 times higher than that of bare Fe₂O₃.This work provides a novel strategy for improving the PEC performance of hematite via co-doping engineering.
基金supported by the Science and Technology Development Plan Project of Shandong Province(2014GSF117015)the National Basic Research Program of China(973 program,2013CB632401)the National Natural Science Foundation of China(51402145)~~
文摘A different approach to synthesize visible‐light‐active sulfur(S)‐doped reduced titania(S‐TiO2‐x)using thiourea dioxide as both the S source and reductant was developed.The structure,morphology,and optical and electronic properties of the as‐prepared S‐TiO2‐x samples were examined by multiple techniques,such as X‐ray diffraction,transmission electron microscopy,X‐ray photoelectron spectroscopy,ultraviolet‐visible diffuse reflectance spectroscopy,Brunauer‐Emmett‐Teller and photocurrent measurements,and electrochemical impedance spectroscopy.The photocatalytic activity of S‐TiO2‐x was evaluated by photodegradation of organic Rhodamine B under visible‐light irradiation.The degradation rate of Rhodamine B by S‐TiO2‐x obtained by calcination was about31,2.5,and3.6times higher than those of pure TiO2,pristine TiO2‐x,and S‐doped TiO2,respectively.In addition,the as‐prepared S‐TiO2‐x exhibited long‐term stable photocatalytic performance in the degradation of Rhodamine B under visible‐light illumination.This report reveals a new approach to prepare stable and highly efficient solar light‐driven photocatalysts for water purification.
基金supported by the National Natural Science Foundation of China(20702064,21177161,31402137)Hubei Province Science Fund for Distinguished Yong Scholars(2013CFA034)+2 种基金the Program for Excellent Talents in Hubei Province(RCJH15001)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education(LYZ1107)the Fundamental Research Funds for the Central University,South-Central University for Nationalities(CZP17077)~~
文摘Ti^（3＋） self-doped anatase three-dimensional（3D） TiO_2 hollow nanoboxes were synthesized via a topological transformation process involving template participation by a facile one-pot hydrothermal treatment with an ethanol solution of zinc powder and TiOF_2. It is worth noting that the 3D TiO_2 hollow nanoboxes are assembled from six single-crystal nanosheets and have dominant exposure of the {001} facets. It is found from EPR spectra that adding zinc powder is an environment-friendly and effective strategy to introduce Ti^（3＋） and oxygen vacancy（Ov） into the bulk of 3D hollow nanoboxes rather than the surface, which is responsible for their enhanced visible photocatalytic properties.The photocatalytic activity was evaluated by measuring the formation rate of hydroxide free radicals using 7-hydroxycoumarin as a probe. The sample prepared with zinc/TiOF_2 mass ratio of0.25 exhibited the highest RhB photodegradation activity under visible-light irradiation with a degradation rate of 96%, which is 4.0-times higher than that of pure TiO_2. The results suggest a novel approach to construct in-situ 3D hierarchical TiO_2 hollow nanoboxes doped with Ti^（3＋） and Ov without introducing any impurity elements for superior visible-light photocatalytic activity.
基金financially supported by the National Natural Science Foundation of China (No. 51364024 and 51404124)Gansu Province Department of Education Fund (No. 2013A-029)the Foundation of State Key Laboratory of Gansu Advanced Nonferrous Metal Materials (Nos. SKL 1316 and SKL 1314)
文摘Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.
基金the financial support of the Iranian nanotechnology initiative
文摘A sintered Ti13Cus7 target was sputtered by reactive direct current （DC） magnetron sputtering with a gas mixture of argon/nitrogen for different sputtering powers. Titanium-coppernitrogen thin films were deposited on Si （111）, glass slide and potassium bromide （KBr） substrates. Phase analysis and structural properties of titanium-copper-nitrogen thin films were studied by X-ray diffraction （XRD）. The chemical bonding was characterized by Fourier transform infrared （FTIR） spectroscopy. The results from XRD show that the observed phases are nano-crystallite cubic anti rhenium oxide （anti ReO3） structures of titanium doped Cu3N （Ti：Cu3N） and nanocrystallite face centered cubic （fcc） structures of copper. Scanning electron microscopy and energy dispersive X-ray spectroscopy （SEM/EDX） were used to determine the film morphology and atomic titanium/copper ratio, respectively. The films possess continuous and agglomerated structure with an atomic titanium/copper ratio （-0.07） below that of the original target （- 0.15）. The transmittance spectra of the composite films were measured in the range of 360 nm to 1100 nm. Film thickness, refractive index and extinction coefficient were extracted from the measured transmittance using a reverse engineering method. In the visible range, the higher absorption coefficient of the films prepared at lower sputtering power indicates more nitrification in comparison to those prepared at higher sputtering power. This is consistent with the formation of larger Ti：Cu3N crystallites at lower sputtering power. The deposition rate vs. sputtering power shows an abrupt transition from metallic mode to poisoned mode. A complicated behavior of the films＇ resistivity upon sputtering power is shown.
基金support from the National Natural Science Foundation of China(5237011751 and 52301282)the Key R&D program of Shanxi Province(202202070301016)the Shanxi Province Science Foundation for Youths(202303021212044 and 202303021212047).
文摘P2-type Na-NiMn oxides have garnered significant attention for sodium-ion batteries owing to their excellent rate capability.However,they are adversely affected by the harmful P2-O2 phase transitions,which cause substantial capacity degradation and poor cycling performance.In this work,a unique P2(84%)/O3(16%)biphasic layered oxide,Na_(0.76)Ni_(0.22)Mg_(0.11)Mn_(0.57)Ti_(0.1)O_(2)(NNMMT),is successfully designed and synthesized by a Mg/Ti co-doping strategy.The doping of Mg and Ti can form stable O-TM-O bonds,while the biphasic structure generates distinctive interlocked interfaces at the boundaries.The harmful phase transition caused by the interlayer slip and structural strain is well suppressed under the synergistic effect of these two factors.As a result,NNMMT demonstrates exceptional capacity and cycling stability(reversible capacity of 109.8 mAh g^(-1) at 1 C and capacity retention of 97.35%after 100 cycles).Meanwhile,the higher proportion of the P2 phase enables NNMMT to maintain excellent rate capability(initial discharge capacity of 88.9 mAh g^(-1) at 5 C).Additionally,ex situ X-ray diffraction analyses before and after cycling demonstrated a significant suppression of the detrimental P2-O2 phase transition in NNMMT during the charge-discharge process,leading to a notable enhancement in structural stability.This work provides an innovative and efficient strategy for designing highly stable layered oxide cathodes.
基金Supported by the National Natural Science Foundation of China under Grant No 61735011the Natural Science Foundation of Hebei Province under Grant Nos F2016203389 and F2018105036+2 种基金the Science and Technology Research Project of College and University in Hebei Province under Grant No BJ2017108the Open Subject of Jiangsu Key Laboratory of Meteorological Observation and Information Processing under Grant No KDXS1107the Science and Technology Project of Tangshan City under Grant No 17130257a
文摘We experimentally demonstrate that a tunable supercontinuum（SC） can be generated in a Yb3＋-doped microstructure fiber by the concept of wavelength conversion with a Ti：sapphire femtosecond（fs） laser as the pump.Experimental results show that an emission light around 1040 nm in an anomalous dispersion region is first generated and amplified by fs pulses in the normal dispersion region. Then, SC spectra from 1100 to 1380 nm and 630 to 840 nm can be achieved by combined effects of higher-order soliton fission and Raman soliton self-frequency shift in the anomalous dispersion region and self-phase modulation, dispersive wave, and four-wave mixing in the normal dispersion region. It is also demonstrated that the 20 nm change of pump results in a 280 nm broadband shift of soliton and the further red-shift of soliton is limited by OH-absorption at 1380 nm.
基金supported by the National Nature Science Foundation(grant no.51302140)Shenzhen Science and Technology Plan Project(no.JCYJ20160422102622085,JCYJ20150827165038323)the Natural Science Foundation of SZU(no.2016016).
文摘n-Type polycrystalline SnSe with Ti,Pb co-doping was synthesized by combining mechanical alloying(MA)with spark plasma sintering(SPS).It is revealed that Ti is an effective cationic dopant to convert SnSe from a p-type to an n-type semiconductor,and the thermoelectric performance of the Ti-doped SnSe is also improved in comparison with the pristine sample due to an enhanced power factor.Furthermore,after further Pb doping,an obviously improved electrical conductivity together with a moderate Seebeck coefficient can be achieved,which results in an improvement of the power factor with a maximum value of 300μW m^(−1) K^(−2) at 773 K.Meanwhile,the lattice thermal conductivity is significantly reduced because of the enhanced phonon scattering owing to the mass and strain fluctuations.Therefore,a final ZT value of 0.4 was obtained for composition of Sn_(0.74)Pb_(0.20)Ti_(0.06)Se at 773 K,which is a conservative value for n-type SnSe with cationic dopant prepared by the simple preparation process of MA and SPS.
基金the support by the Zhejiang Provincial Natural Science Foundation of China(Grant No.LTY21B070001)the Scientific and Technological Development Project of Taizhou City(Grant No.22gya08)+1 种基金the Science and Technology Project of Taizhou(22hba02)the Science Foundation of Taizhou University for Distinguished Young Scholars(Grant No.2018JQ001).
文摘The solar-driven selective oxidation of amines to imines has attracted widespread attention due to its green and non-polluting nature,as well as its high selectivity.In this study,a unique S-scheme BiOCl/UiO-66(Ce/Ti)heterojunction was first constructed as an organic aerobic photocatalyst.Under visible light irradiation with water as the sole solvent,the yield of the imine reached 98%.The S-scheme charge transfer mechanism was verified through in situ X-ray photoelectron spectroscopy and electron paramagnetic resonance measurements,revealing the source of excellent photocatalytic activity.Additionally,the synergistic effect of the interface microenvironment generated by the interaction between OVs and Ce-Ti was found to play a significant role in the photocatalytic oxidation process.This work emphasizes the importance of designing a heterojunction interface microenvironment(IME)for achieving efficient photocatalytic selective oxidation of amines.
基金supported by the National Natural Science Foundation of China(62274112)the National Natural Science Foundation of Guangdong province of China(2024B1515020119 and 2022A1515010929)+3 种基金the Science and Technology Plan Project of Shenzhen(JCYJ20220531103601003)Natural Science Foundation of Shandong Province(Nos.ZR2023ME001)the China Postdoctoral Science Foundation(Nos.2023M732609)Doctoral Research Initiation Fund of Weifang University(Nos.2023BS01).
文摘Sb_(2)Te_(3)-based thermoelectric(TE)thin-film generators are an attractive option for wearable electronics.Band engineering can effectively modulate TE performance.However,modulating the band structure of Sb_(2)Te_(3)thin film remains a challenging task.In this work,titanium(Ti)doping effectively modifies the electronic band structure in Sb_(2)Te_(3),optimizing both carrier transport and phonon transport performance.Ti-doping optimizes carrier concentration and resulting in an increase in electrical conductivity from 1420.0 S/cm to 1694.8 S/cm at 300 K.Additionally,Ti doping modulates the balance between the effective mass of charge carriers and carrier concentration,increasing Seebeck coefficient from 106.0μV/K to 114.8μV/K.Both enhancements lead to a peak power factor of 20.9μW·cm^(−1)·K^(−2).Moreover,Ti-induced vibrational modes have reduced the lattice thermal conductivity from 0.62 W·m^(−1)·K^(−1)to 0.22 W·m^(−1)·K^(−1),improving zT from 0.33 to 0.52 at 300 K.The films exhibit excellent flexibility,with an ultralow resistance change ratio(ΔR/R_(0))of less than 7%after 1000 cycles at a 6 mm bending radius.The device achieves a maximum output power of 178.8 nW with a temperature gradient of 30 K in agreement with the finite element analysis,indicating significant potential for wearable electronics.
