Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, p...Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.展开更多
Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons...Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons SF-ZnNC-T(T represents the carbonization temperature)were synthesized without solvents.Through a temperature-controlled process of“melting the zinc gluconate and urea mixture,forming H-bonded polymers,and carbonizing the polymers,”the optimal carbon,SF-ZnNC-900,was obtained with a large surface area(2280 m^(2)g^(-1),highly dispersed Zn sites,and hierarchical pore structures.Consequently,SF-ZnNC-900 demonstrated significantly higher DBT adsorption capacity of43.2 mg S g^(-1),compared to just 4.3 mg S g^(-1)for the precursor.It also demonstrated good reusability,fast adsorption rate,and the ability for ultra-deep desulfurization.The superior DBT adsorption performance resulted from the evaporation of residual zinc species,which generated abundant mesopores that facilitated DBT transformation,as well as the formation of Zn-N_(x) sites that strengthened the host-vip interaction(ΔE=-1.466 e V).The solvent-free synthesized highly dispersed Zn-doped carbon shows great potential for producing sulfur-free fuel oil and for designing metal-loaded carbon adsorbents.展开更多
In this work,a highly sensitive electrochemical sensor based on Zn-doped copper gallium oxide@ordered mesoporous carbon(Zn-CuGaO_(2)@CMK-3)for signal amplification was successfully developed for the simultaneous detec...In this work,a highly sensitive electrochemical sensor based on Zn-doped copper gallium oxide@ordered mesoporous carbon(Zn-CuGaO_(2)@CMK-3)for signal amplification was successfully developed for the simultaneous detection of sunset yellow(SY)and tartrazine(TZ)in foods.Compared with CuGaO_(2)@CMK-3,Zn-CuGaO_(2)@CMK-3 offered enhanced conductivity and catalytic properties owing to the improved carrier density,which was beneficial to the electrooxidation of SY and TZ.Under the optimal testing conditions,the constructed Zn-CuGaO_(2)@CMK-3/GCE sensor offered a wide linear concentration range(0.25-100.00μmol/L)for the detection of both SY and TZ.The limits of detection for SY and TZ were 0.044 and 0.059μmol/L,respectively.Recovery experiments were performed in milk,white vinegar and biscuit samples,yielding satisfactory recoveries(82.70%-114.80%).Furthermore,the sensor was successfully applied to the determination of the SY and TZ residues in two kinds of carbonated drinks,and the results were nearly consistent with those detected by the high performance liquid chromatography(HPLC)method(P>0.05).展开更多
Following are the comments for the queries raised by Prof. Pawel E. Tomaszewski on our published paper entitled ＂Structural, Optical, and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Sp...Following are the comments for the queries raised by Prof. Pawel E. Tomaszewski on our published paper entitled ＂Structural, Optical, and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique＂ by K. Usharani and A.R. Balu published in Acta Metall. Sin.展开更多
The electronic structures and optical properties of intrinsic β-Ga2O3 and Zn-dopedβ-Ga2O3 are investigated by first-principles calculations. The analysis about the thermal stability shows that Zn-doped β-Ga2O3 rema...The electronic structures and optical properties of intrinsic β-Ga2O3 and Zn-dopedβ-Ga2O3 are investigated by first-principles calculations. The analysis about the thermal stability shows that Zn-doped β-Ga2O3 remains stable. The Zn doping does not change the basic electronic structure of β-Ga2O3, but only generates an empty energy level above the maximum of the valence band, which is shallow enough to make the Zn-doped β-Ga2O3 a typical p-type semiconductor. Because of Zn doping, absorption and reflectivity are enhanced in the near infrared region. The higher absorption and reflectivity of ZnGa（2） than those of ZnGa（1） are due to more empty energy states of ZnGa（2） than those of ZnGa（1） near Ef in the near infrared region.展开更多
The paper reports the fabrication of Zn-doped TiO_2 nanotubes(Zn-TONT)/ZnO nanoflakes heterostructure for the first time,which shows improved performance as a photoanode in dye-sensitized solar cell(DSSC).The layered ...The paper reports the fabrication of Zn-doped TiO_2 nanotubes(Zn-TONT)/ZnO nanoflakes heterostructure for the first time,which shows improved performance as a photoanode in dye-sensitized solar cell(DSSC).The layered structure of this novel nanoporous structure has been analyzed unambiguously by Rutherford backscattering spectroscopy,scanning electron microscopy,and X-ray diffractometer.The cell using the heterostructure as photoanode manifests an enhancement of about an order in the magnitude of the short circuit current and a seven-fold increase in efficiency,over pure TiO_2 photoanodes.Characterizations further reveal that the Zn-TONT is preferentially oriented in [001] direction and there is a Ti metal-depleted interface layer which leads to better band alignment in DSSC.展开更多
The commented paper [1] presents the results on structural, optical, and electrical properties of Zn-doped CdO thin films. Unfortunately, there are several mistakes and errors not found by any of referees. It is neces...The commented paper [1] presents the results on structural, optical, and electrical properties of Zn-doped CdO thin films. Unfortunately, there are several mistakes and errors not found by any of referees. It is necessary to show these mistakes or misleading statements to avoid their use in the future papers by authors and other peoples.展开更多
The point defects and photoluminescence(PL)spectra of gallium nitride(GaN)epilayers with Mg,Zn,and unintentional doping were investigated in this study.The concentration of point defects(Ga vacancy and its related com...The point defects and photoluminescence(PL)spectra of gallium nitride(GaN)epilayers with Mg,Zn,and unintentional doping were investigated in this study.The concentration of point defects(Ga vacancy and its related complexes)in the Zn-doped GaN is consistent with that in the Mg-doped GaN,but lower than that in undoped GaN.It is suggested that Zn(Mg)atoms occupy Ga sites and suppress the formation of Ga vacancies.Comparing the blue luminescence(BL)band intensity of GaN:Zn with that of GaN:Mg,a factor of 10 strong PL intensity demonstrates that a moderate incorporation of Zn to GaN is likely to improve the structural quality of GaN.Detailed studies on 2.93 eV BL band for GaN:Zn reveal that the Zn related BL band behaves as a donor-acceptor pairs character.For the acceptor level,isolated Zn_(Ga)with the activation energy of 0.386 eV above the valence band is obtained from temperature-dependent PL measurements,whereas the deep donor defect responsible for the 2.93 eV band is deduced to be 164 meV below the conduction band.An O_(N)-H complex model is suggested to explain the deep donor origin.展开更多
The effect of Zn dopant on the growth of cadmium oxide （CdO） nanostructures through a sonochemical method wasinvestigated. The X-ray diffraction （XRD） patterns of the nanoparticles show CdO cubic structures for th...The effect of Zn dopant on the growth of cadmium oxide （CdO） nanostructures through a sonochemical method wasinvestigated. The X-ray diffraction （XRD） patterns of the nanoparticles show CdO cubic structures for the produced samples. Fieldemission scanning electron microscope （FESEM） images reveal that morphologies of the samples change, when they are doped withZn atoms, and their sizes reduce. Room temperature photoluminescence （PL） and UV-Vis spectrometers were used to study opticalproperties of the samples. Evaluation of optical properties indicates that different emission bands result from different transitions andthe value of CdO energy band gap increases due to doping. Studies of electrical properties of the nanostructures demonstrate that Zndopant enhances electrical conductivity and photocurrent generation as the result of light illumination on the nanostructures due toimproved density of photo-generated carriers. Considering the obtained outcomes, Zn dopant can alter the physical property of theCdO nanostructures.展开更多
The Li-rich Zn-doped LiNbO 3 (LN) crystals were grown by the Czochralski method. The structure of the crystals was measured by ultraviolet-visible absorption spectra. The results indicated that the Li-rich Zn-doped LN...The Li-rich Zn-doped LiNbO 3 (LN) crystals were grown by the Czochralski method. The structure of the crystals was measured by ultraviolet-visible absorption spectra. The results indicated that the Li-rich Zn-doped LN crystals had the same characteristics as the pure LN crystal. After Zn 2+ entered into the lattice of Li-rich Zn-doped LN crystal, it replaced Nb Li firstly. When there was no Nb Li , Zn 2+ replaced Li + then. The second harmonic generation (SHG) property of Li-rich Zn-doped LiNbO 3 crystal was measured. The results showed that the SHG conversation efficiency of Li-rich Zn-doped LiNbO 3 crystals was higher than that of Zn-doped LiNbO 3 crystals.展开更多
2-methyl-tetrahydrofuran(2-MTHF)is a promising biofuel or fuel additive with excellent burning property,a versatile new-style solvent in organic synthesis,and an important medical intermediate.In this work,a one-pot s...2-methyl-tetrahydrofuran(2-MTHF)is a promising biofuel or fuel additive with excellent burning property,a versatile new-style solvent in organic synthesis,and an important medical intermediate.In this work,a one-pot selective conversion of furfural(FA)into 2-MTHF was carried out over Zn doped Co/NC catalysts.The Zn-Co/NC-1 catalyst with trace Zn dopant(0.38 wt%)exhibited the best performance(yield of 2-MTHF:93.8%).According to the characterizations,it was found that the Zn not only incorporates into the carbon support but also partially dopes into Co nanoparticles.Subsequently,theoretical calculations demonstrated that the doping of Zn in carbon support can effectively enhance the electron transfer from the support to the metallic Co particle,leading to the electron-rich Co surface.The presence of Zn was found to promote the dissociation of hydrogen and to lower the diffusion barrier of hydrogen atom,in favor of the hydrogenation/hydrodeoxygenation processes.Furthermore,the Zn doped models exhibit much lower barrier in breaking C–OH bond of FOL,resulting in higher activity for hydrodeoxygenation of FOL.These theoretical results are consistent with the in situ FT-IR analysis of adsorption substrates and intermediates over Zn doped catalyst.This work reveals the mechanism of dopant Zn tailoring the electronic structure and catalytic performance of active sites,providing a deep insight into the design of economical and high-performance catalysts for hydrogenation/hydrodeoxygenation of biomass feedstocks.展开更多
As global energy consumption rises,developing efficient energy-saving materials is crucial for alleviating energy pressure.Passive daytime radiative cooling materials are promising for energyfree refrigeration.The wid...As global energy consumption rises,developing efficient energy-saving materials is crucial for alleviating energy pressure.Passive daytime radiative cooling materials are promising for energyfree refrigeration.The wide band gap and the absorption of infrared photons through lattice vibrations of the SrZrO_(3)crystal make it a potential passive radiative cooling material,but its solar reflectivity and atmospheric window emissivity can be further enhanced.For this purpose,a series of Zn-doped SrZrO_(3)crystals were prepared by the sol-gel method combined with the solid-phase synthesis method.The effects of Zn doping on the phase structure,electronic structure,spectral radiative characteristics,and passive daytime radiative cooling performance of SrZrO_(3)crystals were investigated by experiments and theoretical calculations.The results show that,on one hand,the changes in the grain morphology and electronic structure caused by Zn doping jointly improved the reflection performance of the crystals in the wavelength of 0.3-2.5μm.On the other hand,the lattice distortion and decrease in the lattice symmetry caused by Zn doping lead to an increase in the photon emissivity for the 8-13μm band.The solar reflectivity of the SrZr_(0.75)Zn_(0.25)O_(2.75)crystal powder can reach 0.892,whereas the atmospheric window emissivity can reach 0.954,both of which are greater than that of SrZrO_(3).The coating prepared with the SrZr_(0.75)Zn_(0.25)O_(2.75)crystal powder as the radiative refrigerant can reach a maximum radiative cooling temperature of 15.3℃under a solar irradiation of 654 W·m^(−2),and the maximum net radiative power is 64.7 W·m^(−2).These results indicate that SrZr_(0.75)Zn_(0.25)O_(2.75)is an excellent passive daytime radiative cooling material.展开更多
Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （...Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.展开更多
Neutral aqueous rechargeable Co_(3)O_(4)//Zn batteries with high-output voltage and outstanding cycling stability have yielded new insights into wearable energy-storage devices.To meet the increasing demand for a mean...Neutral aqueous rechargeable Co_(3)O_(4)//Zn batteries with high-output voltage and outstanding cycling stability have yielded new insights into wearable energy-storage devices.To meet the increasing demand for a means of powering wearable and portable devices,the development of a high-performance fiber-shaped Co//Zn battery would be highly desirable.However,the intrinsically poor conductivity of C 03O4 significantly restricts the application of these high-capacity and high-rate aqueous rechargeable battery.Encouragingly,density functional theory(DFT)calculations demonstrate that the substitution of Zn for Co^(3+)leads to an insulatormetal transition in the Zn-doped Co_(3)O_(4)(Zn-Co_(3)O_(4)).In this study,we used metallic Zn-Co_(3)O_(4)nanowire arrays(NWAs)as a novel binder-free cathode to successfully fabricate an all-solid-state fiber-shaped aqueous rechargeable(AFAR)Co//Zn battery.The resulting fiber-shaped Co//Zn battery takes advantage of the enhanced conductivity,increased capacity,and improved rate capability of Zn-Co_(3)O_(4)NWAs to yield a remarkable capacity of 1.25 mAh·cm^(-2)at a current density of 0.5 mA·cm^(-2),extraordinary rate capability(60.8%capacity retention at a high current density of 20 mA·cm^(-2))and an admirable energy density of 772.6 mWh·cm^(-3).Thus,the successful construction of Zn-Co_(3)O_(4)NWAs provides valuable insights into the design of high-capacity and high-rate cathode materials for aqueous rechargeable high-voltage batteries.展开更多
Intrinsic fi-Ga203 and Zn-doped β-Ga203 films were prepared using RF magnetron sputtering. The effects of the Zn doping and thermal annealing on the structural and optical properties are investigated. In compar- ison...Intrinsic fi-Ga203 and Zn-doped β-Ga203 films were prepared using RF magnetron sputtering. The effects of the Zn doping and thermal annealing on the structural and optical properties are investigated. In compar- ison with the intrinsic β-Ga203 films, the microstructure, optical transmittance, optical absorption, optical energy gap, and photoluminescence ofZn-doped β-Ga203 films change significantly. The post-annealed β-Ga203 films are polycrystalline. After Zn doping, the crystallization deteriorates, the optical band gap shrinks, the transmittance decreases and the UV, blue, and green emission bands are enhanced.展开更多
Amorphous gallium oxide(a-Ga_(2)O_(3))has a low carrier concentration and limited mobility,which constrains its application in neuromorphic computing.In this study,Zndoped Ga_(2)O_(3)(ZGO)artificial synaptic devices w...Amorphous gallium oxide(a-Ga_(2)O_(3))has a low carrier concentration and limited mobility,which constrains its application in neuromorphic computing.In this study,Zndoped Ga_(2)O_(3)(ZGO)artificial synaptic devices were fabricated under oxygen-free conditions using radio-frequency magnetron sputtering(RFMS).Compared to undoped Ga_(2)O_(3),the ZGO device exhibited a 106-fold increase in excitatory postsynaptic current under 254 nm illumination,with the response intensity positively correlated with the optical pulse parameters.Under light pulse modulation,the devices demonstrated dynamic behavior transitioning from short-term plasticity to long-term plasticity,including paired-pulse facilitation and the learning-forgetting-relearning process.Furthermore,the electrical and optical energy consumption of synaptic events are as low as 28 fJ and 2 nJ,respectively.The mechanism analysis indicates that the persistent photoconductivity effect in the ZGO thin film is attributed to the abundant oxygen vacancies.A multi-layer perceptron simulation based on ZGO devices achieved a 90.74%accuracy in handwritten digit recognition,and maintained 76.18%accuracy even with 50%noise.Zn doping provides a new material design approach for Ga_(2)O_(3)-based neuromorphic devices,demonstrating potential for future applications in neuromorphic computing.展开更多
In this study,nano films of pure NiO and films doped with zinc and copper concertation(1%,3%,5%)and their mixture for 5%under 100 nm thickness were generated on glass bases using the solgel process at a temperature of...In this study,nano films of pure NiO and films doped with zinc and copper concertation(1%,3%,5%)and their mixture for 5%under 100 nm thickness were generated on glass bases using the solgel process at a temperature of 298 K.The Cu,Zn-doped NiO and nano NiO optical characteristics were examined throughout a wavelength range of 300 to 800 nm,with high transmittance values of 94%in the Vis-NIR.Transmittance films after doped copper and zinc have dropped to 5%(91%and 92%),respectively.The index of refraction,coefficient of extinction,optical conductivity and the dielctric constants(real and imaginary)were also studied.The results show that the optical conductivity of NiO׃Zn and NiO׃Cu films increased at the room temperature with increasing the dopant concentrations.展开更多
Tetracyclines are refractory pollutants that cause persistent harm to the environment and human health.Therefore,it is urgently necessary to develop methods to promote the efficient degradation and conversion of tetra...Tetracyclines are refractory pollutants that cause persistent harm to the environment and human health.Therefore,it is urgently necessary to develop methods to promote the efficient degradation and conversion of tetracyclines in wastewater.This report proposes a photobiocatalytic synergistic system involving the coupling of GeO_(2)/Zn-doped phosphotungstic acid hydrate/TiO_(2)(GeO_(2)/Zn-HPW/TiO_(2))-loaded photocatalytic optical hollow fibers(POHFs)and an algalebacterial biofilm.The GeO_(2)/Zn-HPW/TiO_(2) photocatalyst exhibits a broad absorption edge extending to 1000 nm,as well as high-efficiency photoelectric conversion and electron transfer,which allow the GeO_(2)/Zn-HPW/TiO_(2)-coated POHFs to provide high light intensity to promote biofilm growth.The resulting high photocatalytic activity rapidly and stably reduces the toxicity and increases the biodegradability of tetracycline-containing wastewater.The biofilm enriched with Salinarimonas,Coelastrella sp.,and Rhizobium,maintains its activity for the rapid photocatalytic degradation and biotransformation of intermediates to generate the O_(2) required for photocatalysis.Overall,the synergistic photocatalytic biofilm system developed herein provides an effective and efficient approach for the rapid degradation and conversion of water containing high concentrations of tetracycline.展开更多
基金Project(cstc2011jj A50008)supported by the Natural Science Foundation of Chongqing,ChinaProject(14ZB0025)supported by Education Department of Sichuan Province,China
文摘Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.
基金supported by the National Natural Science Foundation of China(Grant No.22378065,22278077,22278076)。
文摘Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons SF-ZnNC-T(T represents the carbonization temperature)were synthesized without solvents.Through a temperature-controlled process of“melting the zinc gluconate and urea mixture,forming H-bonded polymers,and carbonizing the polymers,”the optimal carbon,SF-ZnNC-900,was obtained with a large surface area(2280 m^(2)g^(-1),highly dispersed Zn sites,and hierarchical pore structures.Consequently,SF-ZnNC-900 demonstrated significantly higher DBT adsorption capacity of43.2 mg S g^(-1),compared to just 4.3 mg S g^(-1)for the precursor.It also demonstrated good reusability,fast adsorption rate,and the ability for ultra-deep desulfurization.The superior DBT adsorption performance resulted from the evaporation of residual zinc species,which generated abundant mesopores that facilitated DBT transformation,as well as the formation of Zn-N_(x) sites that strengthened the host-vip interaction(ΔE=-1.466 e V).The solvent-free synthesized highly dispersed Zn-doped carbon shows great potential for producing sulfur-free fuel oil and for designing metal-loaded carbon adsorbents.
基金financially supported by the Key R&D Program of Shandong Province,China(2023CXGC010712)GINW acknowledges funding support from the MacDiarmid Institute for Advanced Materials and Nanotechnology.
文摘In this work,a highly sensitive electrochemical sensor based on Zn-doped copper gallium oxide@ordered mesoporous carbon(Zn-CuGaO_(2)@CMK-3)for signal amplification was successfully developed for the simultaneous detection of sunset yellow(SY)and tartrazine(TZ)in foods.Compared with CuGaO_(2)@CMK-3,Zn-CuGaO_(2)@CMK-3 offered enhanced conductivity and catalytic properties owing to the improved carrier density,which was beneficial to the electrooxidation of SY and TZ.Under the optimal testing conditions,the constructed Zn-CuGaO_(2)@CMK-3/GCE sensor offered a wide linear concentration range(0.25-100.00μmol/L)for the detection of both SY and TZ.The limits of detection for SY and TZ were 0.044 and 0.059μmol/L,respectively.Recovery experiments were performed in milk,white vinegar and biscuit samples,yielding satisfactory recoveries(82.70%-114.80%).Furthermore,the sensor was successfully applied to the determination of the SY and TZ residues in two kinds of carbonated drinks,and the results were nearly consistent with those detected by the high performance liquid chromatography(HPLC)method(P>0.05).
文摘Following are the comments for the queries raised by Prof. Pawel E. Tomaszewski on our published paper entitled ＂Structural, Optical, and Electrical Properties of Zn-Doped CdO Thin Films Fabricated by a Simplified Spray Pyrolysis Technique＂ by K. Usharani and A.R. Balu published in Acta Metall. Sin.
基金Project supported by the National Natural Science Foundation of China(Grant No.10974077)the Natural Science Foundation of Shandong Province,China(Grant No.2009ZRB01702)the Shandong Provincial Higher Educational Science and Technology Program,China(Grant No.J10LA08)
文摘The electronic structures and optical properties of intrinsic β-Ga2O3 and Zn-dopedβ-Ga2O3 are investigated by first-principles calculations. The analysis about the thermal stability shows that Zn-doped β-Ga2O3 remains stable. The Zn doping does not change the basic electronic structure of β-Ga2O3, but only generates an empty energy level above the maximum of the valence band, which is shallow enough to make the Zn-doped β-Ga2O3 a typical p-type semiconductor. Because of Zn doping, absorption and reflectivity are enhanced in the near infrared region. The higher absorption and reflectivity of ZnGa（2） than those of ZnGa（1） are due to more empty energy states of ZnGa（2） than those of ZnGa（1） near Ef in the near infrared region.
基金UGC-DAE CSR,Indore,for funding through a collaborative project and SAIF IIT Bombay for the help with SEMsupported by the Michigan Space Grant Consortium+1 种基金by Hope CollegeDAE-BRNS for funding the preliminary works
文摘The paper reports the fabrication of Zn-doped TiO_2 nanotubes(Zn-TONT)/ZnO nanoflakes heterostructure for the first time,which shows improved performance as a photoanode in dye-sensitized solar cell(DSSC).The layered structure of this novel nanoporous structure has been analyzed unambiguously by Rutherford backscattering spectroscopy,scanning electron microscopy,and X-ray diffractometer.The cell using the heterostructure as photoanode manifests an enhancement of about an order in the magnitude of the short circuit current and a seven-fold increase in efficiency,over pure TiO_2 photoanodes.Characterizations further reveal that the Zn-TONT is preferentially oriented in [001] direction and there is a Ti metal-depleted interface layer which leads to better band alignment in DSSC.
文摘The commented paper [1] presents the results on structural, optical, and electrical properties of Zn-doped CdO thin films. Unfortunately, there are several mistakes and errors not found by any of referees. It is necessary to show these mistakes or misleading statements to avoid their use in the future papers by authors and other peoples.
基金the Beijing City Financial Fund(No.PXM2012_014202_000201)。
文摘The point defects and photoluminescence(PL)spectra of gallium nitride(GaN)epilayers with Mg,Zn,and unintentional doping were investigated in this study.The concentration of point defects(Ga vacancy and its related complexes)in the Zn-doped GaN is consistent with that in the Mg-doped GaN,but lower than that in undoped GaN.It is suggested that Zn(Mg)atoms occupy Ga sites and suppress the formation of Ga vacancies.Comparing the blue luminescence(BL)band intensity of GaN:Zn with that of GaN:Mg,a factor of 10 strong PL intensity demonstrates that a moderate incorporation of Zn to GaN is likely to improve the structural quality of GaN.Detailed studies on 2.93 eV BL band for GaN:Zn reveal that the Zn related BL band behaves as a donor-acceptor pairs character.For the acceptor level,isolated Zn_(Ga)with the activation energy of 0.386 eV above the valence band is obtained from temperature-dependent PL measurements,whereas the deep donor defect responsible for the 2.93 eV band is deduced to be 164 meV below the conduction band.An O_(N)-H complex model is suggested to explain the deep donor origin.
基金Ahvaz Branch, Islamic Azad University for the financial support in this research work
文摘The effect of Zn dopant on the growth of cadmium oxide （CdO） nanostructures through a sonochemical method wasinvestigated. The X-ray diffraction （XRD） patterns of the nanoparticles show CdO cubic structures for the produced samples. Fieldemission scanning electron microscope （FESEM） images reveal that morphologies of the samples change, when they are doped withZn atoms, and their sizes reduce. Room temperature photoluminescence （PL） and UV-Vis spectrometers were used to study opticalproperties of the samples. Evaluation of optical properties indicates that different emission bands result from different transitions andthe value of CdO energy band gap increases due to doping. Studies of electrical properties of the nanostructures demonstrate that Zndopant enhances electrical conductivity and photocurrent generation as the result of light illumination on the nanostructures due toimproved density of photo-generated carriers. Considering the obtained outcomes, Zn dopant can alter the physical property of theCdO nanostructures.
文摘The Li-rich Zn-doped LiNbO 3 (LN) crystals were grown by the Czochralski method. The structure of the crystals was measured by ultraviolet-visible absorption spectra. The results indicated that the Li-rich Zn-doped LN crystals had the same characteristics as the pure LN crystal. After Zn 2+ entered into the lattice of Li-rich Zn-doped LN crystal, it replaced Nb Li firstly. When there was no Nb Li , Zn 2+ replaced Li + then. The second harmonic generation (SHG) property of Li-rich Zn-doped LiNbO 3 crystal was measured. The results showed that the SHG conversation efficiency of Li-rich Zn-doped LiNbO 3 crystals was higher than that of Zn-doped LiNbO 3 crystals.
基金supported by the National Natural Science Foundation of China(22078277 and 21908185)the Project of Hunan Provincial Natural Science Foundation of China(2020JJ5532 and 2021JJ30658)+5 种基金the Degree&Postgraduate Education Reform Project of Hunan Provincial(XDCX2019B095 and CX20190489)the Guang Dong Basic and Applied Basic Research Foundation(2021A1515110789 and 2021A1515110136)the Science and Technology Innovation Program of Hunan Province(2021RC2089)the Research Initiation Project of Xiangtan University(KZ08076)the Environment-friendly Chemical Process Integration Technology Hunan Province Key Laboratorythe Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization。
文摘2-methyl-tetrahydrofuran(2-MTHF)is a promising biofuel or fuel additive with excellent burning property,a versatile new-style solvent in organic synthesis,and an important medical intermediate.In this work,a one-pot selective conversion of furfural(FA)into 2-MTHF was carried out over Zn doped Co/NC catalysts.The Zn-Co/NC-1 catalyst with trace Zn dopant(0.38 wt%)exhibited the best performance(yield of 2-MTHF:93.8%).According to the characterizations,it was found that the Zn not only incorporates into the carbon support but also partially dopes into Co nanoparticles.Subsequently,theoretical calculations demonstrated that the doping of Zn in carbon support can effectively enhance the electron transfer from the support to the metallic Co particle,leading to the electron-rich Co surface.The presence of Zn was found to promote the dissociation of hydrogen and to lower the diffusion barrier of hydrogen atom,in favor of the hydrogenation/hydrodeoxygenation processes.Furthermore,the Zn doped models exhibit much lower barrier in breaking C–OH bond of FOL,resulting in higher activity for hydrodeoxygenation of FOL.These theoretical results are consistent with the in situ FT-IR analysis of adsorption substrates and intermediates over Zn doped catalyst.This work reveals the mechanism of dopant Zn tailoring the electronic structure and catalytic performance of active sites,providing a deep insight into the design of economical and high-performance catalysts for hydrogenation/hydrodeoxygenation of biomass feedstocks.
基金supported by the Science and Technology Projects of Inner Mongolia Autonomous Region(Nos.2025KYPT0028,2022ZD02,and 2022MS05003)the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Nos.NJYT22080 and NMGIRT2319)+1 种基金the Basic Scientific Research Expenses Program of Universities Directly under Inner Mongolia Autonomous Region(Nos.JY20220041 and JY20220062)the Industrial Technology Innovation Program of IMAST(No.2024RCYJ02007).
文摘As global energy consumption rises,developing efficient energy-saving materials is crucial for alleviating energy pressure.Passive daytime radiative cooling materials are promising for energyfree refrigeration.The wide band gap and the absorption of infrared photons through lattice vibrations of the SrZrO_(3)crystal make it a potential passive radiative cooling material,but its solar reflectivity and atmospheric window emissivity can be further enhanced.For this purpose,a series of Zn-doped SrZrO_(3)crystals were prepared by the sol-gel method combined with the solid-phase synthesis method.The effects of Zn doping on the phase structure,electronic structure,spectral radiative characteristics,and passive daytime radiative cooling performance of SrZrO_(3)crystals were investigated by experiments and theoretical calculations.The results show that,on one hand,the changes in the grain morphology and electronic structure caused by Zn doping jointly improved the reflection performance of the crystals in the wavelength of 0.3-2.5μm.On the other hand,the lattice distortion and decrease in the lattice symmetry caused by Zn doping lead to an increase in the photon emissivity for the 8-13μm band.The solar reflectivity of the SrZr_(0.75)Zn_(0.25)O_(2.75)crystal powder can reach 0.892,whereas the atmospheric window emissivity can reach 0.954,both of which are greater than that of SrZrO_(3).The coating prepared with the SrZr_(0.75)Zn_(0.25)O_(2.75)crystal powder as the radiative refrigerant can reach a maximum radiative cooling temperature of 15.3℃under a solar irradiation of 654 W·m^(−2),and the maximum net radiative power is 64.7 W·m^(−2).These results indicate that SrZr_(0.75)Zn_(0.25)O_(2.75)is an excellent passive daytime radiative cooling material.
文摘Zinc-air batteries have recently attracted considerable interest owing to the larger storage capacity and lower cost compared to their lithium-ion counterparts. Electrode catalysts for the oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） play a critical role in the operation of rechargeable zinc-air batteries. Herein, we report a simple and scalable strategy to fabricate porous carbon polyhedra using Zn-doped Co-based zeolitic imidazolate frameworks （ZnCo-ZIFs） as precursors. Strikingly, Zn doping leads to smaller Co nanoparticles and higher nitrogen content, which in turn enhances the ORR and OER activities of the obtained porous carbon polyhedra. The synergistic effect of the N-doped carbon and cobalt nanoparticles in the composite, the improved conductivity resulting from the high graphitization of carbon, and the large surface area of the porous polyhedral structure resulted in porous carbon polyhedra with excellent ORR and OER electrocatalytic activity in alkaline media. More importantly, air cathodes based on the optimal porous carbon polyhedra further exhibited superior performance to Pt/C catalysts in primary and rechargeable zinc-air batteries.
基金the National Natural Science Foundation of China(No.51703241)the Fundamental Research Funds for the Central Universities(No.020514380183)+1 种基金the Key Research Program of Frontier Science of Chinese Academy of Sciences(No.QYZDB-SSW-SLH031)the Science and Technology Project of Nanchang(No.2017-SJSYS-008).
文摘Neutral aqueous rechargeable Co_(3)O_(4)//Zn batteries with high-output voltage and outstanding cycling stability have yielded new insights into wearable energy-storage devices.To meet the increasing demand for a means of powering wearable and portable devices,the development of a high-performance fiber-shaped Co//Zn battery would be highly desirable.However,the intrinsically poor conductivity of C 03O4 significantly restricts the application of these high-capacity and high-rate aqueous rechargeable battery.Encouragingly,density functional theory(DFT)calculations demonstrate that the substitution of Zn for Co^(3+)leads to an insulatormetal transition in the Zn-doped Co_(3)O_(4)(Zn-Co_(3)O_(4)).In this study,we used metallic Zn-Co_(3)O_(4)nanowire arrays(NWAs)as a novel binder-free cathode to successfully fabricate an all-solid-state fiber-shaped aqueous rechargeable(AFAR)Co//Zn battery.The resulting fiber-shaped Co//Zn battery takes advantage of the enhanced conductivity,increased capacity,and improved rate capability of Zn-Co_(3)O_(4)NWAs to yield a remarkable capacity of 1.25 mAh·cm^(-2)at a current density of 0.5 mA·cm^(-2),extraordinary rate capability(60.8%capacity retention at a high current density of 20 mA·cm^(-2))and an admirable energy density of 772.6 mWh·cm^(-3).Thus,the successful construction of Zn-Co_(3)O_(4)NWAs provides valuable insights into the design of high-capacity and high-rate cathode materials for aqueous rechargeable high-voltage batteries.
基金supported by the National Natural Science Foundation of China(No.10974077)the Natural Science Foundation of Shandong Province,China(No.2009ZRB01702)the Shandong Province Higher Educational Science andTechnology Program,China(No. J10LA08)
文摘Intrinsic fi-Ga203 and Zn-doped β-Ga203 films were prepared using RF magnetron sputtering. The effects of the Zn doping and thermal annealing on the structural and optical properties are investigated. In compar- ison with the intrinsic β-Ga203 films, the microstructure, optical transmittance, optical absorption, optical energy gap, and photoluminescence ofZn-doped β-Ga203 films change significantly. The post-annealed β-Ga203 films are polycrystalline. After Zn doping, the crystallization deteriorates, the optical band gap shrinks, the transmittance decreases and the UV, blue, and green emission bands are enhanced.
基金supported by the National Key Research and Development Program of China (2022YFB3606603)the Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China (2020ZZ111, 2020ZZ113 and 2021ZZ130)the Natural Science Foundation of Fujian Province of China (2024J01281)。
文摘Amorphous gallium oxide(a-Ga_(2)O_(3))has a low carrier concentration and limited mobility,which constrains its application in neuromorphic computing.In this study,Zndoped Ga_(2)O_(3)(ZGO)artificial synaptic devices were fabricated under oxygen-free conditions using radio-frequency magnetron sputtering(RFMS).Compared to undoped Ga_(2)O_(3),the ZGO device exhibited a 106-fold increase in excitatory postsynaptic current under 254 nm illumination,with the response intensity positively correlated with the optical pulse parameters.Under light pulse modulation,the devices demonstrated dynamic behavior transitioning from short-term plasticity to long-term plasticity,including paired-pulse facilitation and the learning-forgetting-relearning process.Furthermore,the electrical and optical energy consumption of synaptic events are as low as 28 fJ and 2 nJ,respectively.The mechanism analysis indicates that the persistent photoconductivity effect in the ZGO thin film is attributed to the abundant oxygen vacancies.A multi-layer perceptron simulation based on ZGO devices achieved a 90.74%accuracy in handwritten digit recognition,and maintained 76.18%accuracy even with 50%noise.Zn doping provides a new material design approach for Ga_(2)O_(3)-based neuromorphic devices,demonstrating potential for future applications in neuromorphic computing.
文摘In this study,nano films of pure NiO and films doped with zinc and copper concertation(1%,3%,5%)and their mixture for 5%under 100 nm thickness were generated on glass bases using the solgel process at a temperature of 298 K.The Cu,Zn-doped NiO and nano NiO optical characteristics were examined throughout a wavelength range of 300 to 800 nm,with high transmittance values of 94%in the Vis-NIR.Transmittance films after doped copper and zinc have dropped to 5%(91%and 92%),respectively.The index of refraction,coefficient of extinction,optical conductivity and the dielctric constants(real and imaginary)were also studied.The results show that the optical conductivity of NiO׃Zn and NiO׃Cu films increased at the room temperature with increasing the dopant concentrations.
基金supported in part by the National Natural Science Foundation of China(NSFC)(52176178,51876018)Innovation Research Group of Universities in Chongqing(CXQT21035)+2 种基金Scientific and Technological Research Programof Chongqing Municipal Education Commission of China(KJZD-M202201101)Chongqing Postgraduate Innovation Project(CYS22318)Chongqing University of Technology Graduate Education High Quality Development Project(gzlcx20222022).
文摘Tetracyclines are refractory pollutants that cause persistent harm to the environment and human health.Therefore,it is urgently necessary to develop methods to promote the efficient degradation and conversion of tetracyclines in wastewater.This report proposes a photobiocatalytic synergistic system involving the coupling of GeO_(2)/Zn-doped phosphotungstic acid hydrate/TiO_(2)(GeO_(2)/Zn-HPW/TiO_(2))-loaded photocatalytic optical hollow fibers(POHFs)and an algalebacterial biofilm.The GeO_(2)/Zn-HPW/TiO_(2) photocatalyst exhibits a broad absorption edge extending to 1000 nm,as well as high-efficiency photoelectric conversion and electron transfer,which allow the GeO_(2)/Zn-HPW/TiO_(2)-coated POHFs to provide high light intensity to promote biofilm growth.The resulting high photocatalytic activity rapidly and stably reduces the toxicity and increases the biodegradability of tetracycline-containing wastewater.The biofilm enriched with Salinarimonas,Coelastrella sp.,and Rhizobium,maintains its activity for the rapid photocatalytic degradation and biotransformation of intermediates to generate the O_(2) required for photocatalysis.Overall,the synergistic photocatalytic biofilm system developed herein provides an effective and efficient approach for the rapid degradation and conversion of water containing high concentrations of tetracycline.
