The CulnSe2 compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CulnSe2 films were compacted to improve surface morphology. The films were characterized...The CulnSe2 compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CulnSe2 films were compacted to improve surface morphology. The films were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. It is indicated that ideal stoichiometrie CulnSe2 films can be obtained by the selenization of Cu-In precursor deposited at a current density of 20 mA/cm^2. Single-phase CulnSe2 is formed in the selenization proeess, and it exhibits preferred orientation along the （112） plane. The CulnSe2 films with smooth surface can be obtained under the pressure of 500 MPa at 60℃.展开更多
Effective charge separation and rapid interfacial H_(2) production are imperative for the construction of efficient photocatalysts.Compared to Pt,the metallic Ag co‐catalyst with its strong electron‐trapping ability...Effective charge separation and rapid interfacial H_(2) production are imperative for the construction of efficient photocatalysts.Compared to Pt,the metallic Ag co‐catalyst with its strong electron‐trapping ability and excellent electronic conductivity typically exhibits an extremely limited photocatalytic H_(2-)evolution rate owing to its sluggish interfacial H_(2)‐generation reaction.In this study,amorphous AgSe_(x) was incorporated in situ onto metallic Ag as a novel and excellent H_(2)‐evolution active site to boost the interfacial H_(2)‐generation rate of Ag nanoparticles in a TiO_(2)/Ag system.Core‐shell Ag@AgSe_(x)nanoparticle‐modified TiO_(2)photocatalysts were prepared via a two‐step pathway involving the photodeposition of metallic Ag and the selective surface selenization of metallic Ag to yield amorphous AgSe_(x)shells.The as‐prepared TiO_(2)/Ag@AgSe_(x)(20μL)photocatalyst exhibited an excellent H_(2‐)production performance of 853.0μmol h^(-1)g^(-1),prominently outperforming the TiO_(2)and TiO_(2)/Ag samples by factors of 11.6 and 2.4,respectively.Experimental investigations and DFT calculations revealed that the enhanced H_(2‐)generation activity of the TiO_(2)/Ag@AgSe_(x)photocatalyst could be accounted by synergistic interactions of the Ag@AgSe_(x)co‐catalyst.Essentially,the metallic Ag core could quickly capture and transport the photoinduced electrons from TiO_(2)to the amorphous AgSe_(x)shell,whereas the amorphous AgSe_(x)shell provided large active sites for boosting the interfacial H_(2)evolution.This study offers a facile route for the construction of novel core‐shell co‐catalysts for sustainable H_(2)evolution.展开更多
Selenization reaction with the in situ prepared NaHSe has been successfully developed to occur in aqueous solution.The technique affords a method to upload the bioactive Se element on cotton products in semi-industria...Selenization reaction with the in situ prepared NaHSe has been successfully developed to occur in aqueous solution.The technique affords a method to upload the bioactive Se element on cotton products in semi-industrial scale.The antibacterial tests revealed that the selenized cotton possessed a potent and prolonged antimicrobial effect against both Gram-positive S.aureus and Gram-negative E.coli bacteria.This work discloses a practical method for preparing the selenium-containing antibacterial materials concisely and directly with industrial application potential.展开更多
Bulk group IB transition-metal chalcogenides have been widely explored due to their applications in thermoelectrics.However,a layered two-dimensional form of these materials has been rarely reported.Here,we realize se...Bulk group IB transition-metal chalcogenides have been widely explored due to their applications in thermoelectrics.However,a layered two-dimensional form of these materials has been rarely reported.Here,we realize semiconducting Cu_(2)Se by direct selenization of Cu(111).Scanning tunneling microcopy measurements combined with first-principles calculations allow us to determine the structural and electronic properties of the obtained structure.X-ray photoelectron spectroscopy data reveal chemical composition of the sample,which is Cu_(2)Se.The observed moire pattern indicates a lattice mismatch between Cu_(2)Se and the underlying Cu(111)-√3×√3 surface.Differential conductivity obtained by scanning tunneling spectroscopy demonstrates that the synthesized Cu_(2)Se exhibits a band gap of 0.78 eV.Furthermore,the calculated density of states and band structure demonstrate that the isolated Cu_(2)Se is a semiconductor with an indirect band gap of-0.8 eV,which agrees quite well with the experimental results.Our study provides a simple pathway varying toward the synthesis of novel layered 2D transition chalcogenides materials.展开更多
Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transp...Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transport.During the post-selenization process,understanding crystal growth mechanisms,and improving layer quality are essential.We explored the effects of ramp rate and annealing temperature on CZTSSe films,using X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscope(SEM),and ultraviolet-visual spectrophotometry(UV-Vis).The optimal performance occurred at 25.25°C/min ramp rate and 530°C annealing.This led to smoother surfaces,higher density,and larger grains.This condition produced a single-layer structure with large grains,no secondary phases,and a 1.14 eV bandgap,making it promising for photovoltaic applications.The study has highlighted the effect of selenization conditions on the characteristics of the CZTSSe absorber layer and has provided valuable information for developing CZTSSe thin film solar cells.展开更多
Platinum diselenide(PtSe2)is a promising transition metal dichalcogenide(TMDC)material with unique properties.It is necessary to find a controllable fabrication method to bridge PtSe2 with other two-dimensional(2D)mat...Platinum diselenide(PtSe2)is a promising transition metal dichalcogenide(TMDC)material with unique properties.It is necessary to find a controllable fabrication method to bridge PtSe2 with other two-dimensional(2D)materials for practical applications,which has rarely been reported so far.Here,we report that the selenization of Pt(111)can be suppressed to form a Se intercalated layer,instead of a PtSe2 monolayer,by inducing confined conditions with a precoating of graphene.Experiments with graphene-island samples demonstrate that the monolayer PtSe2 can be controllably fabricated only on the bare Pt surface,while the Se intercalated layer is formed underneath graphene,as verified by atomic-resolution observations with scanning transmission electron microscopy(STEM)and scanning tunneling microscopy(STM).In addition,the orientation of the graphene island shows a negligible influence on the Se intercalated layer induced by the graphene coating.By extending the application of 2D confined reactions,this work provides a new method to control the fabrication and pattern 2D materials during the fabrication process.展开更多
Traditional studies on transforming selenate and selenite are often limited by static measurements and low spatial resolution.They do not fully consider the impact of moisture content.This paper uses the DGT(diffusive...Traditional studies on transforming selenate and selenite are often limited by static measurements and low spatial resolution.They do not fully consider the impact of moisture content.This paper uses the DGT(diffusive gradients in thin films)technique to deeply explore how moisture changes affect the transformation of selenate and selenite in the environment(changes in properties over time).First,representative soil samples(loess)are prepared,and their moisture content is adjusted.Fixed concentrations of selenate and selenite are added,and then the DGT device simulates their migration in the natural environment.The experiment covers drought,moisture,and high moisture environments,and the experiment is repeated under each condition to ensure the accuracy of the data.The sample quality is verified and further analyzed by ion chromatography(IC)and atomic absorption spectroscopy(AAS).This article uses DGT technology to study the influence of moisture content on the migration and transformation of selenate and selenite in soil.Results indicate that increased moisture content leads to higher concentrations,diffusion rates,and DGT capture efficiency of both selenium species,highlighting the importance of moisture in their environmental behavior.When the moisture content increased from 25%to 65%,the coefficient of variation of selenate and selenite increased.The DGT technique proved effective in capturing spatial heterogeneity and providing high-precision measurements,offering robust data to advance research on selenium behavior in soils.展开更多
Nowadays,energy and environmental problems are becoming increasingly prominent in society,the de-velopment of clean and environmentally friendly energy is in line with the construction of ecological civilization and e...Nowadays,energy and environmental problems are becoming increasingly prominent in society,the de-velopment of clean and environmentally friendly energy is in line with the construction of ecological civilization and energy,which have attracted the attention of many researchers over the past decades.Narrow band gap semiconductor Sb_(2)S_(3)is widely used in the area of solar cells because of its high light absorption coefficient and suitable bandgap width.However,numerous deep-level defects provide plen-tiful photogenerated carrier recombination sites,which restricts the improvement of photoelectrochem-ical properties seriously.In this work,S-scheme Sb_(2)S_(3)@CdSe_(x)S_(1-x)core-shell quasi-one-dimensional het-erojunction photoanodes were prepared on the FTO substrate by a two-step vapor transport deposition(VTD)method,chemical bath deposition(CBD)and in-situ selenization method.The results showed that CdSe_(x)S_(1-x)nanoparticles(NPs)were tightly coated on the Sb_(2)S_(3)nanorods(NRs).The photocurrent den-sity of the Sb_(2)S_(3)@CdSe_(x)S_(1-x)photoanodes was 1.61 mA cm^(-2)under 1.23 VRHE.Compared with the Sb_(2)S_(3)photoanodes(0.61 mA cm^(-2)),Sb_(2)S_(3)@CdSe_(x)S_(1-x)photoanodes obtained a 2.64-fold improvement,and the dark current was effectively reduced.It showed excellent stability and fast photocurrent response in a 600 s optical stability test.It was concluded that:(1)The charge transfer mechanism of the S-scheme can avoid the problem of high recombination rate of photogenerated charge carriers due to the defects of Sb_(2)S_(3)effectively,and realized spatial separation of photogenerated carriers.(2)The[hk 1]oriented Sb_(2)S_(3)NRs and the formed quasi-one-dimensional heterostructures promote efficient carrier transport.(3)The introduction of Se effectively regulated the band structure of CdS,slowed down the photocorrosion of S,and improved the stability of the photoelectrodes significantly.展开更多
Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the applicati...Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the application of organic Se in agriculture animal production.Selenized glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low cost.This assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione peroxidase.This paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of poultry.As a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.展开更多
By allowing H_(2)SeO_(4),Cy_(2)NH,CyNH_(2) or Bz2NH to react respectively with SnPh_(3)Cl(in methanol),SnPh_(2)Cl_(2)(in water+methanol)and MgCl_(2)·6H_(2)O(in methanol)in specific ratios,the studied complexes ar...By allowing H_(2)SeO_(4),Cy_(2)NH,CyNH_(2) or Bz2NH to react respectively with SnPh_(3)Cl(in methanol),SnPh_(2)Cl_(2)(in water+methanol)and MgCl_(2)·6H_(2)O(in methanol)in specific ratios,the studied complexes are obtained.The suggested structures are discrete and polymer,the environment of the tin center being trans trigonal bipyramidal(compound 1),tetrahedral(compound 2)and octahedral(compound 3),the anions behaving as a bidentate selenate.展开更多
The sluggish kinetics and high cost of the noble-metal based electrocatalyst for oxygen evolution reaction(OER)still seriously limits the efficiencies of water splitting.Herein,for the first time,we rationally design ...The sluggish kinetics and high cost of the noble-metal based electrocatalyst for oxygen evolution reaction(OER)still seriously limits the efficiencies of water splitting.Herein,for the first time,we rationally design a porous hierarchical nanoarchitecture,constructed by ultrathin CoSe_(2)embedded Fe-CoO nanosheets(CoSe_(2)@Fe-CoO),which is synthesized via self-assembly hydrolysis driven in-situ synergetic selenization of Fe/Co/O/Se precursor followed by Ostwald ripening.As an OER catalyst,the porous CoSe_(2)@Fe-CoO hybrid with abundant CoOOH electroactive sites delivers a small Tafel of 56.2 m V/dec with very low onset overpotential of 280 m V@10 m A/cm~2and excellent long-term physicochemical stability till 62h without obvious decay,which outperforms well-established benchmark electrocatalysts(RuO_(2)).The boosted OER performance of CoSe_(2)@Fe-CoO nanosheets is mainly attributed to its iron-doping effect,porous nanoarchitecture,and multicomponent synergetic/interfacial effect between ultrathin cobalt(II)oxide and conductive cobalt selenide(CoSe_(2))nanoframework.This work presents a facile construction strategy to find a nonprecious hybrid OER electrocatalyst with excellent performance and long-term stability.展开更多
Reducing the manufacturing cost of solar cells is necessary to their industrial production. Electrodepositing is an effective, non-vacuum method which is very suitable for cutting the manufacturing cost of thin films ...Reducing the manufacturing cost of solar cells is necessary to their industrial production. Electrodepositing is an effective, non-vacuum method which is very suitable for cutting the manufacturing cost of thin films as well as developing its large-scale industrial production. In this study, about 1-μm-thick Cu（In,Ga）Se2（CIGS） precursors were electrodeposited on Mo/glass substrates in aqueous solution utilizing a three-electrode potentiostatic system.Triethanolamine was used as complexing agent, and all parameters of electrodeposition were precisely controlled.After that, the electrodeposited precursors were selenized in a Se atmosphere with different heating ramp rates（60 and 600℃·min^（-1））. High-quality CIGS films were obtained, and their characteristics were investigated by X-ray fluorescence, scanning electron microscopy, energydispersive spectroscopy, X-ray diffraction, Raman spectra and near-infrared-visible（NIR-Vis） spectra. The results reveal that there are many differences between the properties of the films under different heating rates. Finally,CIGS solar cells were fabricated using a fast and a slow heating rate. The maximum efficiencies achieved for the films selenized at 60 and 600℃-min^（-1） are 3.15% and 0.71%, respectively.展开更多
We put forward a two-step route to synthesize vanadium diselenide(VSe_2), a typical transition metal dichalcogenide(TMD). To obtain the VSe_2 film, we first prepare a vanadium film by electron beam evaporation and we ...We put forward a two-step route to synthesize vanadium diselenide(VSe_2), a typical transition metal dichalcogenide(TMD). To obtain the VSe_2 film, we first prepare a vanadium film by electron beam evaporation and we then perform selenization in a vacuum chamber. This method has the advantages of low temperature, is less time-consuming, has a large area, and has a stable performance. At 400?C selenization temperature, we successfully prepare VSe_2 films on both glass and Mo substrates. The prepared VSe_2 has the characteristic of preferential growth along the c-axis, with low transmittance.It is found that the contact between Al and VSe_2/Mo is ohmic contact. Compared to Mo substrate, lower square resistance and higher carrier concentration of the VSe_2/Mo sample reveal that the VSe_2 film may be a potential material for thin film solar cells or other semiconductor devices. The new synthetic strategy that is developed here paves a sustainable way to the application of VSe_2 in photovoltaic devices.展开更多
The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se...The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se_(2)(ACIGS)absorbers.The beneficial effects of Ag doping are demonstrated and their mechanism is explained.It is found that Ag doping significantly improves the films crystallinity.This is believed to be due to the lower melting point of chalcopyrite phase obtained by the Ag doping.This leads to a higher migration ability of the atoms that in turn promotes grain boundary migration and improves the film crystallinity.The Ga enrichment at the interface between the absorber and the back electrode is also alleviated during the selenization annealing.It is found that Ag doping within a specific range can passivate the band tail and improve the quality of the films.Therefore,carrier recombination is reduced and carrier transport is improved.The negative effects of excessive Ag are also demonstrated and their origin is revealed.Because the atomic size of Ag is different from that of Cu,for the Ag/(Ag+Cu)ratio(AAC)≥0.030,lattice distortion is aggravated,and significant micro-strain appears.The atomic radius of Ag is close to those of In and Ga,so that the continued increase in AAC will give rise to the Ag;or Ag;defects.Both the structural and compositional defects degrade the quality of the absorbers and the device performance.An excellent absorber can be obtained at AAC of 0.015.展开更多
基金supported by the Program of Higher-Level Talents of Inner Mongolia University(Nos.Z20090144 and Z20090120)
文摘The CulnSe2 compound was prepared by selenization of Cu-In precursor, which was ultrasonic electrodeposited at constant current. CulnSe2 films were compacted to improve surface morphology. The films were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. It is indicated that ideal stoichiometrie CulnSe2 films can be obtained by the selenization of Cu-In precursor deposited at a current density of 20 mA/cm^2. Single-phase CulnSe2 is formed in the selenization proeess, and it exhibits preferred orientation along the （112） plane. The CulnSe2 films with smooth surface can be obtained under the pressure of 500 MPa at 60℃.
文摘Effective charge separation and rapid interfacial H_(2) production are imperative for the construction of efficient photocatalysts.Compared to Pt,the metallic Ag co‐catalyst with its strong electron‐trapping ability and excellent electronic conductivity typically exhibits an extremely limited photocatalytic H_(2-)evolution rate owing to its sluggish interfacial H_(2)‐generation reaction.In this study,amorphous AgSe_(x) was incorporated in situ onto metallic Ag as a novel and excellent H_(2)‐evolution active site to boost the interfacial H_(2)‐generation rate of Ag nanoparticles in a TiO_(2)/Ag system.Core‐shell Ag@AgSe_(x)nanoparticle‐modified TiO_(2)photocatalysts were prepared via a two‐step pathway involving the photodeposition of metallic Ag and the selective surface selenization of metallic Ag to yield amorphous AgSe_(x)shells.The as‐prepared TiO_(2)/Ag@AgSe_(x)(20μL)photocatalyst exhibited an excellent H_(2‐)production performance of 853.0μmol h^(-1)g^(-1),prominently outperforming the TiO_(2)and TiO_(2)/Ag samples by factors of 11.6 and 2.4,respectively.Experimental investigations and DFT calculations revealed that the enhanced H_(2‐)generation activity of the TiO_(2)/Ag@AgSe_(x)photocatalyst could be accounted by synergistic interactions of the Ag@AgSe_(x)co‐catalyst.Essentially,the metallic Ag core could quickly capture and transport the photoinduced electrons from TiO_(2)to the amorphous AgSe_(x)shell,whereas the amorphous AgSe_(x)shell provided large active sites for boosting the interfacial H_(2)evolution.This study offers a facile route for the construction of novel core‐shell co‐catalysts for sustainable H_(2)evolution.
基金financially supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20190909,BK20181449)Jiangsu Provincial Six Talent Peaks Project(No.XCL-090)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Selenization reaction with the in situ prepared NaHSe has been successfully developed to occur in aqueous solution.The technique affords a method to upload the bioactive Se element on cotton products in semi-industrial scale.The antibacterial tests revealed that the selenized cotton possessed a potent and prolonged antimicrobial effect against both Gram-positive S.aureus and Gram-negative E.coli bacteria.This work discloses a practical method for preparing the selenium-containing antibacterial materials concisely and directly with industrial application potential.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51772087,11904094,51972106,and 11804089)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000)Natural Science Foundation of Hunan Province,China(Grant Nos.2019JJ50034 and 2019JJ50073).
文摘Bulk group IB transition-metal chalcogenides have been widely explored due to their applications in thermoelectrics.However,a layered two-dimensional form of these materials has been rarely reported.Here,we realize semiconducting Cu_(2)Se by direct selenization of Cu(111).Scanning tunneling microcopy measurements combined with first-principles calculations allow us to determine the structural and electronic properties of the obtained structure.X-ray photoelectron spectroscopy data reveal chemical composition of the sample,which is Cu_(2)Se.The observed moire pattern indicates a lattice mismatch between Cu_(2)Se and the underlying Cu(111)-√3×√3 surface.Differential conductivity obtained by scanning tunneling spectroscopy demonstrates that the synthesized Cu_(2)Se exhibits a band gap of 0.78 eV.Furthermore,the calculated density of states and band structure demonstrate that the isolated Cu_(2)Se is a semiconductor with an indirect band gap of-0.8 eV,which agrees quite well with the experimental results.Our study provides a simple pathway varying toward the synthesis of novel layered 2D transition chalcogenides materials.
基金supported by the Science and Technology Innovation Development Program(No.70304901).
文摘Cu_(2)ZnSnSSe_(4)(CZTSSe)thin film solar cells,with adjustable bandgap and rich elemental content,hold promise in next-gen photovoltaics.Crystalline quality is pivotal for efficient light absorption and carrier transport.During the post-selenization process,understanding crystal growth mechanisms,and improving layer quality are essential.We explored the effects of ramp rate and annealing temperature on CZTSSe films,using X-ray diffraction(XRD),Raman spectroscopy,scanning electron microscope(SEM),and ultraviolet-visual spectrophotometry(UV-Vis).The optimal performance occurred at 25.25°C/min ramp rate and 530°C annealing.This led to smoother surfaces,higher density,and larger grains.This condition produced a single-layer structure with large grains,no secondary phases,and a 1.14 eV bandgap,making it promising for photovoltaic applications.The study has highlighted the effect of selenization conditions on the characteristics of the CZTSSe absorber layer and has provided valuable information for developing CZTSSe thin film solar cells.
基金We acknowledge financial support from the National Key Research and Development Program of China(Nos.2016YFA0202300 and 2018YFA0305800)the National Natural Science Foundation of China(Nos.61725107 and 61971035)+1 种基金Beijing Natural Science Foundation(Nos.4192054 and Z190006)Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB30000000 and XDB28000000).
文摘Platinum diselenide(PtSe2)is a promising transition metal dichalcogenide(TMDC)material with unique properties.It is necessary to find a controllable fabrication method to bridge PtSe2 with other two-dimensional(2D)materials for practical applications,which has rarely been reported so far.Here,we report that the selenization of Pt(111)can be suppressed to form a Se intercalated layer,instead of a PtSe2 monolayer,by inducing confined conditions with a precoating of graphene.Experiments with graphene-island samples demonstrate that the monolayer PtSe2 can be controllably fabricated only on the bare Pt surface,while the Se intercalated layer is formed underneath graphene,as verified by atomic-resolution observations with scanning transmission electron microscopy(STEM)and scanning tunneling microscopy(STM).In addition,the orientation of the graphene island shows a negligible influence on the Se intercalated layer induced by the graphene coating.By extending the application of 2D confined reactions,this work provides a new method to control the fabrication and pattern 2D materials during the fabrication process.
文摘Traditional studies on transforming selenate and selenite are often limited by static measurements and low spatial resolution.They do not fully consider the impact of moisture content.This paper uses the DGT(diffusive gradients in thin films)technique to deeply explore how moisture changes affect the transformation of selenate and selenite in the environment(changes in properties over time).First,representative soil samples(loess)are prepared,and their moisture content is adjusted.Fixed concentrations of selenate and selenite are added,and then the DGT device simulates their migration in the natural environment.The experiment covers drought,moisture,and high moisture environments,and the experiment is repeated under each condition to ensure the accuracy of the data.The sample quality is verified and further analyzed by ion chromatography(IC)and atomic absorption spectroscopy(AAS).This article uses DGT technology to study the influence of moisture content on the migration and transformation of selenate and selenite in soil.Results indicate that increased moisture content leads to higher concentrations,diffusion rates,and DGT capture efficiency of both selenium species,highlighting the importance of moisture in their environmental behavior.When the moisture content increased from 25%to 65%,the coefficient of variation of selenate and selenite increased.The DGT technique proved effective in capturing spatial heterogeneity and providing high-precision measurements,offering robust data to advance research on selenium behavior in soils.
基金supported by the National Natural Science Foun-dation of China(No.11804274)the Natural Science Foundation of Shaanxi Province(No.2023-JC-YB-139)the Open Research Fund of State Key Laboratory of Transient Optics and Photonics,Chinese Academy of Sciences(No.SKLST202211).
文摘Nowadays,energy and environmental problems are becoming increasingly prominent in society,the de-velopment of clean and environmentally friendly energy is in line with the construction of ecological civilization and energy,which have attracted the attention of many researchers over the past decades.Narrow band gap semiconductor Sb_(2)S_(3)is widely used in the area of solar cells because of its high light absorption coefficient and suitable bandgap width.However,numerous deep-level defects provide plen-tiful photogenerated carrier recombination sites,which restricts the improvement of photoelectrochem-ical properties seriously.In this work,S-scheme Sb_(2)S_(3)@CdSe_(x)S_(1-x)core-shell quasi-one-dimensional het-erojunction photoanodes were prepared on the FTO substrate by a two-step vapor transport deposition(VTD)method,chemical bath deposition(CBD)and in-situ selenization method.The results showed that CdSe_(x)S_(1-x)nanoparticles(NPs)were tightly coated on the Sb_(2)S_(3)nanorods(NRs).The photocurrent den-sity of the Sb_(2)S_(3)@CdSe_(x)S_(1-x)photoanodes was 1.61 mA cm^(-2)under 1.23 VRHE.Compared with the Sb_(2)S_(3)photoanodes(0.61 mA cm^(-2)),Sb_(2)S_(3)@CdSe_(x)S_(1-x)photoanodes obtained a 2.64-fold improvement,and the dark current was effectively reduced.It showed excellent stability and fast photocurrent response in a 600 s optical stability test.It was concluded that:(1)The charge transfer mechanism of the S-scheme can avoid the problem of high recombination rate of photogenerated charge carriers due to the defects of Sb_(2)S_(3)effectively,and realized spatial separation of photogenerated carriers.(2)The[hk 1]oriented Sb_(2)S_(3)NRs and the formed quasi-one-dimensional heterostructures promote efficient carrier transport.(3)The introduction of Se effectively regulated the band structure of CdS,slowed down the photocorrosion of S,and improved the stability of the photoelectrodes significantly.
基金supported by the Open Project of Jiangsu Key Laboratory of Animal genetic Breeding and Molecular Design(No.AGBMD202202)the Jiangsu Agricultural Science and Technology Innovation Fund(Nos.[CX(21)3131]and[CX(20)3010])+2 种基金the“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(Nos.[JBGS[2021]027 and JBGS[2021]105])the Science and Education Integration Project of Yangzhou University(No.[KJRH202115])Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Selenium is an essential trace element for humans and animals.As the active center of selenoproteins,the addition of selenium is beneficial to enhance the antioxidant ability.However,the high cost limits the application of organic Se in agriculture animal production.Selenized glucose(SeGlu)is a newly invented organoselenium material with good stability,low toxicity and low cost.This assay found that SeGlu was able to increase selenium deposition in liver of newborn broilers,and enhance the antioxidant capacity of liver by elevating the activities of antioxidant enzymes such as total superoxide dismutase and glutathione peroxidase.This paper as the first example clarifying the mechanism of SeGlu to enhance the antioxidant ability of chicks,shows that SeGlu can be used as an organic selenium enrichment additive for early nutrition of poultry.As a cross-discipline study involving chemistry,biology and agriculture animal science,the work may be beneficial for studies in related fields and prompt the development of the selenium science.
文摘By allowing H_(2)SeO_(4),Cy_(2)NH,CyNH_(2) or Bz2NH to react respectively with SnPh_(3)Cl(in methanol),SnPh_(2)Cl_(2)(in water+methanol)and MgCl_(2)·6H_(2)O(in methanol)in specific ratios,the studied complexes are obtained.The suggested structures are discrete and polymer,the environment of the tin center being trans trigonal bipyramidal(compound 1),tetrahedral(compound 2)and octahedral(compound 3),the anions behaving as a bidentate selenate.
基金the National Natural Science Foundation of China(Grant Nos.21773024,51372033)。
文摘The sluggish kinetics and high cost of the noble-metal based electrocatalyst for oxygen evolution reaction(OER)still seriously limits the efficiencies of water splitting.Herein,for the first time,we rationally design a porous hierarchical nanoarchitecture,constructed by ultrathin CoSe_(2)embedded Fe-CoO nanosheets(CoSe_(2)@Fe-CoO),which is synthesized via self-assembly hydrolysis driven in-situ synergetic selenization of Fe/Co/O/Se precursor followed by Ostwald ripening.As an OER catalyst,the porous CoSe_(2)@Fe-CoO hybrid with abundant CoOOH electroactive sites delivers a small Tafel of 56.2 m V/dec with very low onset overpotential of 280 m V@10 m A/cm~2and excellent long-term physicochemical stability till 62h without obvious decay,which outperforms well-established benchmark electrocatalysts(RuO_(2)).The boosted OER performance of CoSe_(2)@Fe-CoO nanosheets is mainly attributed to its iron-doping effect,porous nanoarchitecture,and multicomponent synergetic/interfacial effect between ultrathin cobalt(II)oxide and conductive cobalt selenide(CoSe_(2))nanoframework.This work presents a facile construction strategy to find a nonprecious hybrid OER electrocatalyst with excellent performance and long-term stability.
基金financially supported by the National High Technology Research and Development Program of China(No.2015AA034201)the National Natural Science Foundation of China(No.11474355)the Chinese Universities Scientific Fund(No.2017LX002)
文摘Reducing the manufacturing cost of solar cells is necessary to their industrial production. Electrodepositing is an effective, non-vacuum method which is very suitable for cutting the manufacturing cost of thin films as well as developing its large-scale industrial production. In this study, about 1-μm-thick Cu（In,Ga）Se2（CIGS） precursors were electrodeposited on Mo/glass substrates in aqueous solution utilizing a three-electrode potentiostatic system.Triethanolamine was used as complexing agent, and all parameters of electrodeposition were precisely controlled.After that, the electrodeposited precursors were selenized in a Se atmosphere with different heating ramp rates（60 and 600℃·min^（-1））. High-quality CIGS films were obtained, and their characteristics were investigated by X-ray fluorescence, scanning electron microscopy, energydispersive spectroscopy, X-ray diffraction, Raman spectra and near-infrared-visible（NIR-Vis） spectra. The results reveal that there are many differences between the properties of the films under different heating rates. Finally,CIGS solar cells were fabricated using a fast and a slow heating rate. The maximum efficiencies achieved for the films selenized at 60 and 600℃-min^（-1） are 3.15% and 0.71%, respectively.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51572132,61674082,and 61774089)the National Key R&D Program of China(Grant No.2018YFB1500202)+3 种基金Tianjin Natural Science Foundation of Key Project,China(Grant Nos.18JCZDJC31200 and 16JCZDJC30700)Yang Fan Innovative and Entrepreneurial Research Team Project,China(Grant No.2014YT02N037)111 Project,China(Grant No.B16027)the International Cooperation Base,China(Grant No.2016D01025)
文摘We put forward a two-step route to synthesize vanadium diselenide(VSe_2), a typical transition metal dichalcogenide(TMD). To obtain the VSe_2 film, we first prepare a vanadium film by electron beam evaporation and we then perform selenization in a vacuum chamber. This method has the advantages of low temperature, is less time-consuming, has a large area, and has a stable performance. At 400?C selenization temperature, we successfully prepare VSe_2 films on both glass and Mo substrates. The prepared VSe_2 has the characteristic of preferential growth along the c-axis, with low transmittance.It is found that the contact between Al and VSe_2/Mo is ohmic contact. Compared to Mo substrate, lower square resistance and higher carrier concentration of the VSe_2/Mo sample reveal that the VSe_2 film may be a potential material for thin film solar cells or other semiconductor devices. The new synthetic strategy that is developed here paves a sustainable way to the application of VSe_2 in photovoltaic devices.
基金supported by the analysis support of the State Key Laboratory of New Ceramics and Fine Processing。
文摘The AgCuInGa alloy precursors with different Ag concentrations are fabricated by sputtering an Ag target and a CuInGa target.The precursors are selenized in the H_(2)Se-containing atmosphere to prepare(Ag,Cu)(In,Ga)Se_(2)(ACIGS)absorbers.The beneficial effects of Ag doping are demonstrated and their mechanism is explained.It is found that Ag doping significantly improves the films crystallinity.This is believed to be due to the lower melting point of chalcopyrite phase obtained by the Ag doping.This leads to a higher migration ability of the atoms that in turn promotes grain boundary migration and improves the film crystallinity.The Ga enrichment at the interface between the absorber and the back electrode is also alleviated during the selenization annealing.It is found that Ag doping within a specific range can passivate the band tail and improve the quality of the films.Therefore,carrier recombination is reduced and carrier transport is improved.The negative effects of excessive Ag are also demonstrated and their origin is revealed.Because the atomic size of Ag is different from that of Cu,for the Ag/(Ag+Cu)ratio(AAC)≥0.030,lattice distortion is aggravated,and significant micro-strain appears.The atomic radius of Ag is close to those of In and Ga,so that the continued increase in AAC will give rise to the Ag;or Ag;defects.Both the structural and compositional defects degrade the quality of the absorbers and the device performance.An excellent absorber can be obtained at AAC of 0.015.
