Supported Ir catalysts were prepared using layered double hydrotalcite‐like materials,such as Mg_(3)Al_(1-x)Fe_(x),containing Fe and Al species in varying amounts as supports.These Ir catalysts were applied for the s...Supported Ir catalysts were prepared using layered double hydrotalcite‐like materials,such as Mg_(3)Al_(1-x)Fe_(x),containing Fe and Al species in varying amounts as supports.These Ir catalysts were applied for the selective hydrogenation of cinnamaldehyde(CAL).When x was changed from 0(Ir/Mg_(3)Al)to 1(Ir/Mg_(3)Fe),the rate of CAL hydrogenation reached a maximum at approximately x=0.25,while the selectivity to unsaturated alcohol,i.e.,cinnamyl alcohol,monotonously increased from 44.9%to 80.3%.Meanwhile,the size of the supported Ir particles did not change significantly with x,remaining at 1.7-0.2 nm,as determined by transmission electron microscopy.The chemical state of Ir and Fe species in the Ir/Mg3Al1-xFex catalysts was examined by temperature programmed reduction by H2 and X‐ray photoelectron spectroscopy.The surface of the supported Ir particles was also examined through the in‐situ diffuse reflectance infrared Fourier‐transform of a probe molecule of CO.On the basis of these characterization results,the effects of Fe doping to Mg_(3)Al on the structural and catalytic properties of Ir particles in selective CAL hydrogenation were discussed.The significant factors are the electron transfer from Fe2+in the Mg_(3)Al_(1–x)Fex support to the dispersed Ir particles and the surface geometry.展开更多
The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped Zn O nanostructures have been fabricated through simple, v...The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped Zn O nanostructures have been fabricated through simple, versatile and quick low temperature solution route with reproducible results. The amount of Fe dopant is found to play a significant role for the growth of crystal dimension. The effect of changes in the morphology can be obviously observed in the structural and micro-structural investigations, which may be due to a driving force induced by dipole-dipole interaction. The band gap of Zn O nanostructures is highly shifted towards the visible range with increase of Fe contents, while ferromagnetic properties have been significantly improved.The prepared nanostructures have been found to be nontoxic to SH-SY5 Y Cells. The present study clearly indicates that the Fe doping provides an effective way of tailoring the crystal dimension, optical band-gap and ferromagnetic properties of Zn O nanostructure-materials with nontoxic nature, which make them potential for visible light activated photocatalyst to overcome environmental pollution, fabricate spintronics devices and biosafe drug delivery agent.展开更多
A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural a...A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural air diffusion electrode(NADE)to construct the heterogeneous visible-light-driven photoelectro-Fenton(HEVL-PEF)process to enhance the degradation and mineralization of tetracycline(TC).Interfacial≡Fe sites,OVs and Bi metal were simultaneously constructed via Fe doping,which effectively improved visible light absorption and the separation efficiency of photogenerated carriers to further accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ),achieving Fenton reaction recycling.HE-VL-PEF process could achieve enhanced treatment of pollutants,thanks to the synergistic effect of electro-Fenton(EF)and photo-Fenton(PF).NADE exhibited excellent H_(2)O_(2) electrosynthesis without external oxygen-pumping equipment.Under the irradiation of visible light,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve more photoelectrons to accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ)or directly activate H2O2.DFT calculations also clearly demonstrated that except for the fast charge separation and transfer,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve a faster electron transport between Fe-O,facilitating Fe site acquire more electron.Consequently,the Fe-Bi/Bi_(7)O_(9)I_(3)/OVs in HE-VL-PEF process presented performance superiorities including excellent pollutant removal(91.91%),low electric energy consumption of 66.34 k Wh/kg total organic carbon(TOC),excellent reusability and wide p H adaptability(3–9).展开更多
As a promising cathode material for aqueous zinc-ion batteries,1T-MoS_(2)has been extensively investigated because of its facile two-dimensional ion-diffusion channels and high electrical conductivity.However,the limi...As a promising cathode material for aqueous zinc-ion batteries,1T-MoS_(2)has been extensively investigated because of its facile two-dimensional ion-diffusion channels and high electrical conductivity.However,the limited number of available Zn storage sites,i.e.,limited capacity,hinders its application because the inserted Zn^(2+),which form strong electrostatic interactions with 1T-MoS_(2),preventing subsequent Zn^(2+)insertion.Currently,the approach of enlarging the interlayer distance to reduce electrostatic interactions has been commonly used to enhance the capacity and reduce Zn^(2+)migration barriers.However,an enlarged interlayer spacing can weaken the van der Waals force between 1T-MoS_(2)monolayers,easily disrupting the structural stability.Herein,to address this issue,an effective strategy based on Fe doping is proposed for 1T-MoS_(2)(Fe-1T-MoS_(2)).The theoretical calculations reveal that Fe doping can simultaneously moderate the rate of decrease in the adsorption energy after gradually increasing the number of stored atoms,and enhance the electron delocalization on metal-O bonds.Therefore,the experiment results show that Fe doping can simultaneously activate more Zn storage sites,thus enhancing the capacity,and stabilize the structural stability for improved cycling performance.Consequently,Fe-1T-MoS_(2)exhibits a larger capacity(189 mAh·g^(-1)at 0.1 A·g^(-1))and superior cycling stability(78%capacity retention after 400 cycles at 2 A·g^(-1))than pure 1T-MoS_(2).This work may open up a new avenue for constructing high-performance MoS_(2)-based cathodes.展开更多
CuBi_(2)O_(4)(CBO)photocathodes hold significant promise for efficient photoelectrochemical(PEC)water splitting due to their favorable band gap and theoretical onset potential.However,their practical application is hi...CuBi_(2)O_(4)(CBO)photocathodes hold significant promise for efficient photoelectrochemical(PEC)water splitting due to their favorable band gap and theoretical onset potential.However,their practical application is hindered by poor charge separation efficiency.Herein,we introduce a characteristic in-situ solution Fe-doping strategy that markedly improves photoelectrochemical performance of CBO,doubling the photocurrent density and achieving an unprecedented 190 mV anodic shift in the onset potential.By integrating with an electrochemical oxidation post-treatment,a record incident photon-to-current efficiency(IPCE)exceeding 40% at 0.6 V vs.RHE under visible light illumination is achieved.The versatility of the doping strategy is demonstrated across CBO photocathodes synthesized by different methods with various morphologies,grain sizes,and crystallinities.Mechanistic studies reveal that the gradient distribution of Fe^(3+)ions generates an internal electric field that facilitates efficient charge separation and increases acceptor density.The strong Fe-O bonding also enhances structural stability against photoinduced corrosion.Notably,our investigation uncovers the non-temperature-dependent nature of CBO photocurrent,indicating that PEC performance enhancement primarily depends on reducing carrier recombination rather than improving bulk conductivity.This work lays the groundwork for future advancements in water splitting performance of CBO photocathodes,offering a complementary strategy to conventional methods for enhancing charge separation efficiency.展开更多
Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and r...Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and rapid recombination velocity of the photogenerated electron-hole severely hamper the sustainable implementation of ZnO in photocatalysis.Herein,by one"two birds with one stone"strategy,Fe-doping ZnO porous nanosheets(Fe-ZnOPN)composed of ultrafine nanoparticles can be constructed by hydrothermal synthesis of basic zinc carbonate and controlled low-temperature pyrolytic methods.By highly concentrated Fe-doping effect(>7 wt%),the tailoring ZnO nanograin size(~10 nm)and rich oxygen vacancy of catalyst were accessed by ion/vacancy diffusion and nanocrystal rearrangement,superior to the ZnO porous nanosheets(~37 nm).The obtained Fe-ZnOPN were endowed with a larger specific surface area,improved visible light harvesting ability,light response and separation of charge carriers.Such characters allowed the resulting catalyst to afford a 100%bactericidal efficiency against Pseudomonas aeruginosa and Staphylococcus aureus under visible light irradiation(>420 nm).Impressively,the Fe-ZnOPN could show practical disinfection ability in different water resources and multiple reuse ability.The mechanism study revealed that excellent photocatalytic disinfection performance of Fe-ZnOPN correlated with the in situ generated active oxidative substances,destruction of bacterial biofilm and resulting nucleic acids leakage,thereby causing irreversible physical damage.This study provided a new reference for designing environmentally friendly photocatalytic sterilization materials and disinfectants,which can be used in the practical disinfection of drinking water.展开更多
Air cathodes with high electrocatalytic activity are vital for developing H2/O_(2) proton exchange membrane fuel cells(PEMFC)and Zn-air batteries.However,the state-of-the-art air cathodes suffer from either limited ca...Air cathodes with high electrocatalytic activity are vital for developing H2/O_(2) proton exchange membrane fuel cells(PEMFC)and Zn-air batteries.However,the state-of-the-art air cathodes suffer from either limited catalytic activity or high cost,which thus hinder their applications.Herein,we designed ZIF-8 derived nitrogen and atomic iron dual-doped porous carbon nanocubes as high-quality catalysts for ORR,through a novel gas-doping approach.The porous carbon nanocubic architecture and abundant Fe-Nxactive species endow ZIF-8 derived single atomic iron catalyst(PCN-A@Fe SA)with superior catalytic activity,and surpass Pt/C and a majority of the reported catalysts.Both XAS and DFT calculations suggest that Fe2+N4 moieties are the main active centers that are favorable for oxygen affinity and OH*intermediate desorption,which can result in promising catalytic performance.Most importantly,PCNA@Fe SA can achieve power density of 514 m W cm^(-2) as cathodic catalyst in a PEMFC and discharge peak power density of 185 m W cm^(-2) in an alkaline Zn-air battery.The outstanding performance is derived from both the high specific surface area and high-density of iron single atom in nitrogen doped nanocubic carbon matrix.展开更多
Fe/N/C catalysts,synthesized through the pyrolysis of Fe-doped metal–organic framework (MOF) precursors,have attracted extensive attention owing to their promising oxygen reduction reaction (ORR) catalytic activity i...Fe/N/C catalysts,synthesized through the pyrolysis of Fe-doped metal–organic framework (MOF) precursors,have attracted extensive attention owing to their promising oxygen reduction reaction (ORR) catalytic activity in fuel cells and/or metal-air batteries.However,post-treatments (acid washing,second pyrolysis,and so on) are unavoidable to improve ORR catalytic activity and stability.The method for introducing Fe^(3+) sources (anhydrous Fe Cl_(3)) into the MOF structure,in particular,is a critical step that can avoid time-consuming post-treatments and result in more exposed Fe-N_(x) active sites.Herein,three different Fe doping strategies were systematically investigated to explore their influence on the types of active sites formed and ORR performance.Fe-NC(Zn^(2+)),synthesized by one-step pyrolysis of Fe doped ZIF-8 (Zn^(2+)) precursor which was obtained by adding the anhydrous Fe Cl_(3)source into the Zn(NO_(3))_(2)·6H_(2)O/methanol solution before mixing,possessed the highest Fe-N_(x)active sites due to the high-efficiency substitution of Zn^(2+)ions with Fe^(3+) ions during ZIF-8 growth,the strong interaction between Fe^(3+) ions and N atoms of 2-Methylimidazole (2-MIm),and ZIF-8’s micropore confinement effect.As a result,Fe-NC(Zn^(2+)) presented high ORR activity in the entire p H range (p H=1,7,and 13).At p H=13,Fe-NC(Zn^(2+)) exhibited a half-wave potential (E1/2) of 0.95 V (vs.reversible hydrogen electrode),which was 70 m V higher than that of commercial Pt/C.More importantly,Fe-NC(Zn^(2+)) showed superior ORR stability in neutral media without performance loss after 5,000 cycles.A record-high open-circuit voltage(1.9 V) was obtained when Fe-NC(Zn^(2+)) was used as a cathodic catalyst in assembled Mg-air batteries in neutral media.The assembled liquid and all-solid Mg-air batteries with high performance indicated that Fe-NC(Zn^(2+)) has enormous potential for use in flexible and wearable Mg-air batteries.展开更多
The doping effects on the frustration and the magnetic properties in hexagonal compounds ot YMn0.9A0.1O3 （A=A1, Fe and Cu） are investigated. Experimental results indicate that both the non-magnetic and magnetic ion ...The doping effects on the frustration and the magnetic properties in hexagonal compounds ot YMn0.9A0.1O3 （A=A1, Fe and Cu） are investigated. Experimental results indicate that both the non-magnetic and magnetic ion dopants lead to the increase of magnetic moments and the decrease of the absolute value of Curie-Weiss temperature （｜θcw｜）- Compared with pure YMnOa, the geometrical frustration of YMn0.9 A0. 1O3 is greatly suppressed and the magnetic coupling in that exhibits dopant-dependent. In addition, for the doped YMno.gAo.103, the antiferromagnetic transition temperature （TN） is also suppressed slightly, which shows an abnormal dilution effect and it may be ascribed to the reduction of frustration due to the chemical substitution.展开更多
AlGaN/GaN high electron mobility transistors （HEMTs） grown on Fe-modulation-doped （MD） and unintentionally doped （UID） GaN buffer layers are investigated and compared. Highly resistive GaN buffers （10^9Ω·...AlGaN/GaN high electron mobility transistors （HEMTs） grown on Fe-modulation-doped （MD） and unintentionally doped （UID） GaN buffer layers are investigated and compared. Highly resistive GaN buffers （10^9Ω·cm） are induced by individual mechanisms for the electron traps＇ formation： the Fe MD buffer （sample A） and the UID buffer with high density of edge-type dislocations （7.24×10^9cm^-2, sample B）. The 300K Hall test indicates that the mobility of sample A with Fe doping （2503cm^2V^-1s^-1） is much higher than sample B （1926cm^2V^-1s^-1） due to the decreased scattering effect on the two-dimensional electron gas. HEMT devices are fabricated on the two samples and pulsed I–V measurements are conducted. Device A shows better gate pinch-off characteristics and a higher threshold voltage （-2.63V） compared with device B （-3.71V）. Lower gate leakage current ｜IGS｜ of device A （3.32×10^-7A） is present compared with that of device B （8.29×10^-7A）. When the off-state quiescent points Q_2 （V GQ2=-8V, V DQ2=0V） are on, V th hardly shifts for device A while device B shows ＋0.21V positive threshold voltage shift, resulting from the existence of electron traps associated with the dislocations in the UID-GaN buffer layer under the gate. Under pulsed I–V and transconductance G m–V GS measurement, the device with the Fe MD-doped buffer shows more potential in improving reliability upon off-state stress.展开更多
The effect of Fe-doping on the magnetic properties of the ABO3-type perovskite cobaltites La0.7Ba0.3CoO3（0≤ y≤0.80） is reported. With no apparent structural change in any doped sample, the Curie temperature （Tc）...The effect of Fe-doping on the magnetic properties of the ABO3-type perovskite cobaltites La0.7Ba0.3CoO3（0≤ y≤0.80） is reported. With no apparent structural change in any doped sample, the Curie temperature （Tc） and the magnetization （M） are greatly suppressed for y ≤0.30 samples, while a distinct increase in Tc for the y=0.40 sample is observed. With the further increase of Fe concentration, Tc increases monotonically. Griffiths-like phases in 0.40≤y ≤0.60 samples are confirmed. The formation of the Griffiths-like phase is ascribed to B-site disordering induced isolation of ferromagnetic （FM） clusters above Tc.展开更多
The large single-crystal diamond with FeS doping along the （111） face is synthesized from the FeNi-C system by the temperature gradient method （TGM） under high-pressure and high-temperature （HPHT）. the effects o...The large single-crystal diamond with FeS doping along the （111） face is synthesized from the FeNi-C system by the temperature gradient method （TGM） under high-pressure and high-temperature （HPHT）. the effects of different FeS additive content on the shape, color, and quality of diamond are investigated. It is found that the （111） face of diamond is dominated and the （100） face of diamond disappears gradually with the increase of the FeS content. At the same time, the color of the diamond crystal changes from light yellow to gray-green and even gray-yellow. The stripes and pits corrosion on the diamond surface are observed to turn worse. The effects of FeS doping on the shape and surface morphology of diamond crystal are explained by the number of hang bonds in different surfaces of diamond. It can be shown from the test results of the Fourier transform infrared （FTIR） spectrum that there exists an S element in the obtained diamond. The N element content values in different additive amounts of diamond are calculated. The XPS spectrum results demonstrate that our obtained diamond contains S elements that exist in S-C and S-C-O forms in a diamond lattice. This work contributes to the further understanding and research of FeS-doped large single-crystal diamond characterization.展开更多
Electrocatalytic N2 reduction to ammonia is a fascinating alternative to Haber-Bosch process and also considered as an energy sto rage method.This work,Fe doped MoS2/carbon cloth(CC) has been studied on the electro-ca...Electrocatalytic N2 reduction to ammonia is a fascinating alternative to Haber-Bosch process and also considered as an energy sto rage method.This work,Fe doped MoS2/carbon cloth(CC) has been studied on the electro-catalysis fix nitrogen indicating the doped Fe can indeed enhance the MoS2 material ability.Compared with MoS2/CC,Fe-Mo-S-3/CC not only increases 10 times in the rate of production ammonia,but also 5 times in Faraday efficiency.展开更多
文摘Supported Ir catalysts were prepared using layered double hydrotalcite‐like materials,such as Mg_(3)Al_(1-x)Fe_(x),containing Fe and Al species in varying amounts as supports.These Ir catalysts were applied for the selective hydrogenation of cinnamaldehyde(CAL).When x was changed from 0(Ir/Mg_(3)Al)to 1(Ir/Mg_(3)Fe),the rate of CAL hydrogenation reached a maximum at approximately x=0.25,while the selectivity to unsaturated alcohol,i.e.,cinnamyl alcohol,monotonously increased from 44.9%to 80.3%.Meanwhile,the size of the supported Ir particles did not change significantly with x,remaining at 1.7-0.2 nm,as determined by transmission electron microscopy.The chemical state of Ir and Fe species in the Ir/Mg3Al1-xFex catalysts was examined by temperature programmed reduction by H2 and X‐ray photoelectron spectroscopy.The surface of the supported Ir particles was also examined through the in‐situ diffuse reflectance infrared Fourier‐transform of a probe molecule of CO.On the basis of these characterization results,the effects of Fe doping to Mg_(3)Al on the structural and catalytic properties of Ir particles in selective CAL hydrogenation were discussed.The significant factors are the electron transfer from Fe2+in the Mg_(3)Al_(1–x)Fex support to the dispersed Ir particles and the surface geometry.
基金supported by Higher Education Commission of Pakistan, National Basic Research Program of China (2010CB934602)National Science Foundation of China (51171007 and 51271009)
文摘The modification of nanostructured materials is of great interest due to controllable and unusual inherent properties in such materials. Single phase Fe doped Zn O nanostructures have been fabricated through simple, versatile and quick low temperature solution route with reproducible results. The amount of Fe dopant is found to play a significant role for the growth of crystal dimension. The effect of changes in the morphology can be obviously observed in the structural and micro-structural investigations, which may be due to a driving force induced by dipole-dipole interaction. The band gap of Zn O nanostructures is highly shifted towards the visible range with increase of Fe contents, while ferromagnetic properties have been significantly improved.The prepared nanostructures have been found to be nontoxic to SH-SY5 Y Cells. The present study clearly indicates that the Fe doping provides an effective way of tailoring the crystal dimension, optical band-gap and ferromagnetic properties of Zn O nanostructure-materials with nontoxic nature, which make them potential for visible light activated photocatalyst to overcome environmental pollution, fabricate spintronics devices and biosafe drug delivery agent.
基金financially supported by Key Project of Natural Science Foundation of Tianjin(No.21JCZDJC00320)National Key R&D Program International Cooperation Project(No.2021YFE0106500)+3 种基金Natural Science Foundation of China(No.52170085)Fundamental Research Funds for the Central UniversitiesNankai UniversityNational Research Foundation IRGChina/South Africa Research Cooperation Programme(No.132793)。
文摘A novel Fe-doping three-dimensional fiower-like Bi_(7)O_(9)I_(3) microspheres with plasmonic Bi and rich surface oxygen vacancies(Fe-Bi/Bi_(7)O_(9)I_(3)/OVs)was prepared as catalysts,and further coupled with natural air diffusion electrode(NADE)to construct the heterogeneous visible-light-driven photoelectro-Fenton(HEVL-PEF)process to enhance the degradation and mineralization of tetracycline(TC).Interfacial≡Fe sites,OVs and Bi metal were simultaneously constructed via Fe doping,which effectively improved visible light absorption and the separation efficiency of photogenerated carriers to further accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ),achieving Fenton reaction recycling.HE-VL-PEF process could achieve enhanced treatment of pollutants,thanks to the synergistic effect of electro-Fenton(EF)and photo-Fenton(PF).NADE exhibited excellent H_(2)O_(2) electrosynthesis without external oxygen-pumping equipment.Under the irradiation of visible light,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve more photoelectrons to accelerate the transformation of Fe(Ⅲ)to Fe(Ⅱ)or directly activate H2O2.DFT calculations also clearly demonstrated that except for the fast charge separation and transfer,Fe-Bi/Bi_(7)O_(9)I_(3)/OVs could achieve a faster electron transport between Fe-O,facilitating Fe site acquire more electron.Consequently,the Fe-Bi/Bi_(7)O_(9)I_(3)/OVs in HE-VL-PEF process presented performance superiorities including excellent pollutant removal(91.91%),low electric energy consumption of 66.34 k Wh/kg total organic carbon(TOC),excellent reusability and wide p H adaptability(3–9).
基金supported by the National Natural Science Foundation of China(No.52102318)the Fellowship of China Postdoctoral Science Foundation(Nos.2021TQ0287 and 2022M722855)Xingdian Talent Support Foundation of Yunnan Province(2020).
文摘As a promising cathode material for aqueous zinc-ion batteries,1T-MoS_(2)has been extensively investigated because of its facile two-dimensional ion-diffusion channels and high electrical conductivity.However,the limited number of available Zn storage sites,i.e.,limited capacity,hinders its application because the inserted Zn^(2+),which form strong electrostatic interactions with 1T-MoS_(2),preventing subsequent Zn^(2+)insertion.Currently,the approach of enlarging the interlayer distance to reduce electrostatic interactions has been commonly used to enhance the capacity and reduce Zn^(2+)migration barriers.However,an enlarged interlayer spacing can weaken the van der Waals force between 1T-MoS_(2)monolayers,easily disrupting the structural stability.Herein,to address this issue,an effective strategy based on Fe doping is proposed for 1T-MoS_(2)(Fe-1T-MoS_(2)).The theoretical calculations reveal that Fe doping can simultaneously moderate the rate of decrease in the adsorption energy after gradually increasing the number of stored atoms,and enhance the electron delocalization on metal-O bonds.Therefore,the experiment results show that Fe doping can simultaneously activate more Zn storage sites,thus enhancing the capacity,and stabilize the structural stability for improved cycling performance.Consequently,Fe-1T-MoS_(2)exhibits a larger capacity(189 mAh·g^(-1)at 0.1 A·g^(-1))and superior cycling stability(78%capacity retention after 400 cycles at 2 A·g^(-1))than pure 1T-MoS_(2).This work may open up a new avenue for constructing high-performance MoS_(2)-based cathodes.
基金financial support by the National Natural Science Foundation of China(NSFC,Grant No.22379153 and 22109128)the Ningbo Key Research and Development Project(2023Z147)the Ningbo 3315 Program。
文摘CuBi_(2)O_(4)(CBO)photocathodes hold significant promise for efficient photoelectrochemical(PEC)water splitting due to their favorable band gap and theoretical onset potential.However,their practical application is hindered by poor charge separation efficiency.Herein,we introduce a characteristic in-situ solution Fe-doping strategy that markedly improves photoelectrochemical performance of CBO,doubling the photocurrent density and achieving an unprecedented 190 mV anodic shift in the onset potential.By integrating with an electrochemical oxidation post-treatment,a record incident photon-to-current efficiency(IPCE)exceeding 40% at 0.6 V vs.RHE under visible light illumination is achieved.The versatility of the doping strategy is demonstrated across CBO photocathodes synthesized by different methods with various morphologies,grain sizes,and crystallinities.Mechanistic studies reveal that the gradient distribution of Fe^(3+)ions generates an internal electric field that facilitates efficient charge separation and increases acceptor density.The strong Fe-O bonding also enhances structural stability against photoinduced corrosion.Notably,our investigation uncovers the non-temperature-dependent nature of CBO photocurrent,indicating that PEC performance enhancement primarily depends on reducing carrier recombination rather than improving bulk conductivity.This work lays the groundwork for future advancements in water splitting performance of CBO photocathodes,offering a complementary strategy to conventional methods for enhancing charge separation efficiency.
基金financially supported by the National Natural Science Foundation of China(No.21908085)the Natural Science Foundation of Jiangsu Province+7 种基金China(No.BK20190961)the National Natural Science Foundation(No.42207474)the Natural Science Foundation of Jiangsu Province(No.BK20210895)the Science and Technology Project of Suzhou(No.SKJY2021138)the Science and Education Revitalizing Youth Project of Suzhou(No.KJXW2020049)Suzhou Hospital Association Infection Management Special Research(No.SZSYYXH-2023-ZY1)Suzhou Municipal Health Commission Expert Team Introduction Project(No.SZYJTD201904)Jiangsu Provincial Key Laboratory of Environmental Science and Engineering(No.JSHJZDSYS-202103)。
文摘Visible light-driven environmentally friendly ZnO semiconductor for durable photocatalytic disinfection and purification of drinking water is very promising.However,the high requirement in ultraviolet absorption and rapid recombination velocity of the photogenerated electron-hole severely hamper the sustainable implementation of ZnO in photocatalysis.Herein,by one"two birds with one stone"strategy,Fe-doping ZnO porous nanosheets(Fe-ZnOPN)composed of ultrafine nanoparticles can be constructed by hydrothermal synthesis of basic zinc carbonate and controlled low-temperature pyrolytic methods.By highly concentrated Fe-doping effect(>7 wt%),the tailoring ZnO nanograin size(~10 nm)and rich oxygen vacancy of catalyst were accessed by ion/vacancy diffusion and nanocrystal rearrangement,superior to the ZnO porous nanosheets(~37 nm).The obtained Fe-ZnOPN were endowed with a larger specific surface area,improved visible light harvesting ability,light response and separation of charge carriers.Such characters allowed the resulting catalyst to afford a 100%bactericidal efficiency against Pseudomonas aeruginosa and Staphylococcus aureus under visible light irradiation(>420 nm).Impressively,the Fe-ZnOPN could show practical disinfection ability in different water resources and multiple reuse ability.The mechanism study revealed that excellent photocatalytic disinfection performance of Fe-ZnOPN correlated with the in situ generated active oxidative substances,destruction of bacterial biofilm and resulting nucleic acids leakage,thereby causing irreversible physical damage.This study provided a new reference for designing environmentally friendly photocatalytic sterilization materials and disinfectants,which can be used in the practical disinfection of drinking water.
基金supported by the National Natural Science Foundation of China(NSFC Project Nos.21776104,21476088)the National Key Research and Development Program of China(Project Nos.2016YFB0101201,2017YFB0102900)+1 种基金the Guangdong Provincial Department of Science and Technology(Project No.2015B010106012)the Guangzhou Science,Technology and Innovation Committee(Project Nos.201504281614372,2016GJ006)。
文摘Air cathodes with high electrocatalytic activity are vital for developing H2/O_(2) proton exchange membrane fuel cells(PEMFC)and Zn-air batteries.However,the state-of-the-art air cathodes suffer from either limited catalytic activity or high cost,which thus hinder their applications.Herein,we designed ZIF-8 derived nitrogen and atomic iron dual-doped porous carbon nanocubes as high-quality catalysts for ORR,through a novel gas-doping approach.The porous carbon nanocubic architecture and abundant Fe-Nxactive species endow ZIF-8 derived single atomic iron catalyst(PCN-A@Fe SA)with superior catalytic activity,and surpass Pt/C and a majority of the reported catalysts.Both XAS and DFT calculations suggest that Fe2+N4 moieties are the main active centers that are favorable for oxygen affinity and OH*intermediate desorption,which can result in promising catalytic performance.Most importantly,PCNA@Fe SA can achieve power density of 514 m W cm^(-2) as cathodic catalyst in a PEMFC and discharge peak power density of 185 m W cm^(-2) in an alkaline Zn-air battery.The outstanding performance is derived from both the high specific surface area and high-density of iron single atom in nitrogen doped nanocubic carbon matrix.
基金supported by the National Natural Science Foundation of China(22171266)the FJIRSM&IUE Joint Research Fund(RHZX-2019-002)+2 种基金the STS Project(KFJ-STS-QYZD-2021-09002)the National Key Basic Research Program of China(2017YFA0403402)the Project of the National Natural Science Foundation of China(U1932119)。
文摘Fe/N/C catalysts,synthesized through the pyrolysis of Fe-doped metal–organic framework (MOF) precursors,have attracted extensive attention owing to their promising oxygen reduction reaction (ORR) catalytic activity in fuel cells and/or metal-air batteries.However,post-treatments (acid washing,second pyrolysis,and so on) are unavoidable to improve ORR catalytic activity and stability.The method for introducing Fe^(3+) sources (anhydrous Fe Cl_(3)) into the MOF structure,in particular,is a critical step that can avoid time-consuming post-treatments and result in more exposed Fe-N_(x) active sites.Herein,three different Fe doping strategies were systematically investigated to explore their influence on the types of active sites formed and ORR performance.Fe-NC(Zn^(2+)),synthesized by one-step pyrolysis of Fe doped ZIF-8 (Zn^(2+)) precursor which was obtained by adding the anhydrous Fe Cl_(3)source into the Zn(NO_(3))_(2)·6H_(2)O/methanol solution before mixing,possessed the highest Fe-N_(x)active sites due to the high-efficiency substitution of Zn^(2+)ions with Fe^(3+) ions during ZIF-8 growth,the strong interaction between Fe^(3+) ions and N atoms of 2-Methylimidazole (2-MIm),and ZIF-8’s micropore confinement effect.As a result,Fe-NC(Zn^(2+)) presented high ORR activity in the entire p H range (p H=1,7,and 13).At p H=13,Fe-NC(Zn^(2+)) exhibited a half-wave potential (E1/2) of 0.95 V (vs.reversible hydrogen electrode),which was 70 m V higher than that of commercial Pt/C.More importantly,Fe-NC(Zn^(2+)) showed superior ORR stability in neutral media without performance loss after 5,000 cycles.A record-high open-circuit voltage(1.9 V) was obtained when Fe-NC(Zn^(2+)) was used as a cathodic catalyst in assembled Mg-air batteries in neutral media.The assembled liquid and all-solid Mg-air batteries with high performance indicated that Fe-NC(Zn^(2+)) has enormous potential for use in flexible and wearable Mg-air batteries.
基金Supported by the National Natural Science Foundation of China under Grant No 11104091
文摘The doping effects on the frustration and the magnetic properties in hexagonal compounds ot YMn0.9A0.1O3 （A=A1, Fe and Cu） are investigated. Experimental results indicate that both the non-magnetic and magnetic ion dopants lead to the increase of magnetic moments and the decrease of the absolute value of Curie-Weiss temperature （｜θcw｜）- Compared with pure YMnOa, the geometrical frustration of YMn0.9 A0. 1O3 is greatly suppressed and the magnetic coupling in that exhibits dopant-dependent. In addition, for the doped YMno.gAo.103, the antiferromagnetic transition temperature （TN） is also suppressed slightly, which shows an abnormal dilution effect and it may be ascribed to the reduction of frustration due to the chemical substitution.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61204017 and 61334002the National Basic Research Program of Chinathe National Science and Technology Major Project of China
文摘AlGaN/GaN high electron mobility transistors （HEMTs） grown on Fe-modulation-doped （MD） and unintentionally doped （UID） GaN buffer layers are investigated and compared. Highly resistive GaN buffers （10^9Ω·cm） are induced by individual mechanisms for the electron traps＇ formation： the Fe MD buffer （sample A） and the UID buffer with high density of edge-type dislocations （7.24×10^9cm^-2, sample B）. The 300K Hall test indicates that the mobility of sample A with Fe doping （2503cm^2V^-1s^-1） is much higher than sample B （1926cm^2V^-1s^-1） due to the decreased scattering effect on the two-dimensional electron gas. HEMT devices are fabricated on the two samples and pulsed I–V measurements are conducted. Device A shows better gate pinch-off characteristics and a higher threshold voltage （-2.63V） compared with device B （-3.71V）. Lower gate leakage current ｜IGS｜ of device A （3.32×10^-7A） is present compared with that of device B （8.29×10^-7A）. When the off-state quiescent points Q_2 （V GQ2=-8V, V DQ2=0V） are on, V th hardly shifts for device A while device B shows ＋0.21V positive threshold voltage shift, resulting from the existence of electron traps associated with the dislocations in the UID-GaN buffer layer under the gate. Under pulsed I–V and transconductance G m–V GS measurement, the device with the Fe MD-doped buffer shows more potential in improving reliability upon off-state stress.
基金Project supported by the National Basic Research Program of China (Grant No 2009CB929201)the National Natural Science Foundation of China (Grant No 10774179)
文摘The effect of Fe-doping on the magnetic properties of the ABO3-type perovskite cobaltites La0.7Ba0.3CoO3（0≤ y≤0.80） is reported. With no apparent structural change in any doped sample, the Curie temperature （Tc） and the magnetization （M） are greatly suppressed for y ≤0.30 samples, while a distinct increase in Tc for the y=0.40 sample is observed. With the further increase of Fe concentration, Tc increases monotonically. Griffiths-like phases in 0.40≤y ≤0.60 samples are confirmed. The formation of the Griffiths-like phase is ascribed to B-site disordering induced isolation of ferromagnetic （FM） clusters above Tc.
基金Project supported by the National Natural Science Foundation of China(Grant No.51772120)the Project for Key Science and Technology Research of Henan Province,China(Grant Nos.162102210275 and 172102210283)+1 种基金the Key Scientific Research Project in Colleges and Universities of Henan Province,China(Grant Nos.18A430017 and 17A430020)the Professional Practice Demonstration Base for Professional Degree Graduate in Material Engineering of Henan Polytechnic University,China(Grant No.2016YJD03)
文摘The large single-crystal diamond with FeS doping along the （111） face is synthesized from the FeNi-C system by the temperature gradient method （TGM） under high-pressure and high-temperature （HPHT）. the effects of different FeS additive content on the shape, color, and quality of diamond are investigated. It is found that the （111） face of diamond is dominated and the （100） face of diamond disappears gradually with the increase of the FeS content. At the same time, the color of the diamond crystal changes from light yellow to gray-green and even gray-yellow. The stripes and pits corrosion on the diamond surface are observed to turn worse. The effects of FeS doping on the shape and surface morphology of diamond crystal are explained by the number of hang bonds in different surfaces of diamond. It can be shown from the test results of the Fourier transform infrared （FTIR） spectrum that there exists an S element in the obtained diamond. The N element content values in different additive amounts of diamond are calculated. The XPS spectrum results demonstrate that our obtained diamond contains S elements that exist in S-C and S-C-O forms in a diamond lattice. This work contributes to the further understanding and research of FeS-doped large single-crystal diamond characterization.
基金supported by Science and Technology Commission of Shanghai Municipality(Nos.17ZR1441200,18QA1402400 and 18230743400)National Natural Science Foundation of China(Nos.21771124,21901156)。
文摘Electrocatalytic N2 reduction to ammonia is a fascinating alternative to Haber-Bosch process and also considered as an energy sto rage method.This work,Fe doped MoS2/carbon cloth(CC) has been studied on the electro-catalysis fix nitrogen indicating the doped Fe can indeed enhance the MoS2 material ability.Compared with MoS2/CC,Fe-Mo-S-3/CC not only increases 10 times in the rate of production ammonia,but also 5 times in Faraday efficiency.
