Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrent...Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrently construct heterogeneous interfaces,adjust phase structure,and regulate electronic configuration,thereby enhancing OER performance.Thanks to the role of CeO_(2)coupling in reducing the activation-energy and accelerating the reaction kinetics,the heterogeneous NixSey/CeO_(2)catalyst exhibits a low overpotential of 218 mV at 10 mA/cm2and long-term stability(>400 h)in 1.0 mol/L KOH for OER.Moreover,the post-OER characterization reveals that the NixSeymatrix is reconstructed into NiOOH,while the incorporated CeO_(2)nanocrystals self-assemble into larger polycrystalline particles.Theoretical analysis further demonstrates that the optimized electronic states at NiOOH/CeO_(2)interfaces can modulate intermediate chemisorption toward favorable OER kinetics.This study offers fresh perspectives on the synthesis and structure-activity relationship of CeO_(2)-coupled electrocatalysts.展开更多
Next-generation fire safety systems demand precise detection and motion recognition of flames.In-sensor computing,which integrates sensing,memory,and processing capabilities,has emerged as a key technology in flame de...Next-generation fire safety systems demand precise detection and motion recognition of flames.In-sensor computing,which integrates sensing,memory,and processing capabilities,has emerged as a key technology in flame detection.However,the implementation of hardware-level functional demonstrations based on artificial vision systems in the solar-blind ultraviolet(UV)band(200-280 nm)is hindered by the weak detection capability.Here,we propose Ga_(2)O_(3)/In_(2)Se_(3) heterojunctions for the ferroelectric(abbreviation:Fe)optoelectronic sensor(abbreviation:OES)array(5×5 pixels),which is capable of ultraweak UV light detection with an ultrahigh detectivity through ferroelectric regulation and features in configurable multimode functionality.The Fe-OES array can directly sense different flame motions and simulate the non-spiking gradient neurons of insect visual system.Moreover,the flame signal can be effectively amplified in combination with leaky integration-and-fire neuron hardware.Using this Fe-OES system and neuromorphic hardware,we successfully demonstrate three flame processing tasks:achieving efficient flame detection across all time periods with terminal and cloud-based alarms;flame motion recognition with a lightweight convolutional neural network achieving 96.47%accuracy;and flame light recognition with 90.51%accuracy by means of a photosensitive artificial neural system.This work provides effective tools and approaches for addressing a variety of complex flame detection tasks.展开更多
The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts rem...The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.展开更多
Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy ...Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy is proposed to construct adjacent Nb-Nb diatomic pairs with Se/O-coordination(Se4-Nb2-O2)in N-doped carbon-confined amorphous selenide clusters(a-Nb-Se/O@NC).Synergistic carbon confinement and hydrothermal oxygenation induce amorphization of Nb–Se bonds,eliminating crystalline rigidity while creating isotropic dual-ion transport channels and high-density active sites enriched with dangling bonds,thereby enhancing structural integrity and Na+storage capacity.The unique Se/O-coordinated Nb-Nb diatomic configuration establishes an electron-delocalized system,where the low electronegativity of Se counterbalances electron withdrawal from coordinated O at Nb centers.These strengthen d-p orbital hybridization,reduce Na+adsorption energy,and optimize charge transfer pathways and reaction kinetics in the amorphous clusters.Electrochemical tests reveal that the a-Nb-Se/O@NC anode delivers a high reversible capacity of 312.57 mAh g^(−1)and exceptional cyclic stability(103%capacity retention)after 5000 cycles at 10.0 A g^(−1).Assembled SIHCs achieve outstanding energy/power densities(207.1 Wh kg^(−1)/18966 W kg^(−1)),surpassing most amorphous and crystalline counterparts.This work provides methodological insights for the design of electrodes in high-power storage devices through atomic modulation and electronic optimization of amorphous selenides.展开更多
Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaero...Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.展开更多
The shell structure design has been recognized as a highly efficient strategy to buffer the severe volume expansion and consecutive pulverization of conversion-type anodes.Nevertheless,construction of a functional she...The shell structure design has been recognized as a highly efficient strategy to buffer the severe volume expansion and consecutive pulverization of conversion-type anodes.Nevertheless,construction of a functional shell with a stabilized structure that meets the demands of both high electronic conductivity and feasible pathways for Na^(+)ions has been a challenge so far.Herein,we design a two-in-one shell configuration for bimetal selenides to achieve fast sodium storage within broadened voltage windows.The hybridized shell,which benefits from the combination of titanium dioxide quantum dots and amorphous carbon,can not only effectively buffer the strain and maintain structural integrity but also allow facile and reversible transport of electrons and Na^(+)uptake for electrode materials during sodiation/desodiation processes,resulting in increased reaction kinetics and diffusion of sodium ions,conferring many benefits to the functionality of conversion-type electrode materials.As a representative material,Ni-CoSe_(2) with such structural engineering shows a reversible capacity of 515 mAh g^(−1)at 0.1 A g^(−1)and a stable capacity of 416 mAh g^(−1)even at 6.4 A g^(−1);more than 80%of the capacity at 0.1 A g^(−1)could be preserved,so that this strategy holds great promise for designing fast-charging conversion-type anodes in the future.展开更多
Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of...Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of readily available substrates and reagent and good yield of the products.展开更多
Recently,metal selenides have obtained widespread attention as electrode materials for alkali(Li^(+)/Na^(+)/K^(+))batteries due to their promising theoretical capacity and mechanism.Nevertheless,metal selenides,simila...Recently,metal selenides have obtained widespread attention as electrode materials for alkali(Li^(+)/Na^(+)/K^(+))batteries due to their promising theoretical capacity and mechanism.Nevertheless,metal selenides,similar to metal oxides and sulfides,also suffer from severe volume explosion during repeated charge/discharge processes,which results in the structure collapse and the following pulverization of electrode materials.Hence,it leads to poor cycle stability and influencing their further application.In order to solve these issues,some special strategies,including elemental doping,coupling with carbon materials,synthesis of the bimetal selenides with heterostructure,etc.,have been gradually applied to design novel electrode materials with outstanding electrochemical performance.Herein,the recent research progress on metal selenides as anodes for alkali ion batteries is summarized,including the regulation of crystal structure,synthesis strategies,modification methods,and electrochemical mechanisms and kinetics.Besides,the challenges of metal selenides and the perspective for future electrode material design are proposed.It is hoped to pave a way for the development of metal selenide electrode materials for the potential applications for alkali metal ion(Li^(+)/Na^(+)/K^(+))batteries.展开更多
Exploration of novel narrow bandgap semiconductors for overall water splitting is vital for the realization of practical solar H2 production.In the work,solid solutions of zinc selenide and copper gallium selenide wit...Exploration of novel narrow bandgap semiconductors for overall water splitting is vital for the realization of practical solar H2 production.In the work,solid solutions of zinc selenide and copper gallium selenide with absorption edge wavelengths ranging from 480 to 730 nm were developed.Using these metal selenides as H2-evolving photocatalysts,CoOx/BiVO4 as the O2-evolving photocatalyst,and reduced graphene oxide as the electron mediator,all-solid-state Z-scheme overall pure water splitting systems were constructed.The rate of photocatalytic H2 evolution from aqueous solutions containing Na2S and Na2SO3 as the electron donors was evaluated while employing these selenide photocatalysts at various Zn/(Zn+Cu)and Ga/Cu molar ratios.The data demonstrate that efficient Z-scheme overall water splitting was significantly correlated to the photoelectrochemical performance of the selenide photocatalysts acting as photocathodes,rather than the photocatalytic activities of these materials during the sacrificial H2 evolution.展开更多
Bimetallic selenide with core-shell structure(CoSe_(2)/ZnSe/NC@ZnSe/NC)has been successfully prepared through facile carbonization and selenization processes of its core-shell metal-organic framework precursors,in whi...Bimetallic selenide with core-shell structure(CoSe_(2)/ZnSe/NC@ZnSe/NC)has been successfully prepared through facile carbonization and selenization processes of its core-shell metal-organic framework precursors,in which the precursor is synthesized by epitaxial growth of zinc-based zeolite imidazolate framework(ZIF-8)on the surface of cobalt-based and zinc-based zeolite imidazolate framework(ZIF-67@ZIF-8).The coreshell structure has the advantage of alleviating the volume expansion during repeated insertion and extraction of sodium ions which can effectively avoid structural collapse.Additionally,bimetallic selenides and heterostructure are effective strategies to greatly improve the rate capability of the material.Therefore,the core-shell structural CoSe2/ZnSe/NC@ZnSe/NC material can maintain the original dodecahedron structure and delivers a specific capacity of 308.6 mAh·g^(-1)at 1.0 A·g^(-1)after 300 cycles with the desirable capacity retention of 90%.With the synergistic effects of heterostructure and core-shell structure,CoSe_(2)/ZnSe/NC@ZnSe/NC exhibits better electrochemical performance than CoSe_(2)/ZnSe/NC and CoSe_(2)/NC.These prove that both core-shell structure and heterostructure have positive effects on improving the electrochemical properties of materials.展开更多
In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene ...In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.展开更多
Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conduc...Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of LSBs.To solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb LiPSs.At the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction processes.The mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)calculations.The electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at 0.2C.And after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.展开更多
In the presence of BiCl3/Al or BiCl3/Fe, in THF-H2O, allylic (benzylic) bromides or α-bromoketones react with diorganyl diselenides to give allylic (benzylic) selenides orα-organylselenocarbonyl compounds respective...In the presence of BiCl3/Al or BiCl3/Fe, in THF-H2O, allylic (benzylic) bromides or α-bromoketones react with diorganyl diselenides to give allylic (benzylic) selenides orα-organylselenocarbonyl compounds respectively in moderate to good yields.展开更多
Reduction of diaryldiselenides by the system of Cp2TiCl2/Bu'MgBr/THF gave the nucleophilic arylselenium complex. They reacted with diaryl iodonium salts to afford unsymmetrical diaryl selenides in high yields.
1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladiumcatalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic b...1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladiumcatalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic bromides.展开更多
A mild, one-pot procedure for the synthesis of vinyl ethers in good yields from 2-hydroxyalkyl phenyl selenides with primary or secondary organic halides has been developed.
基金supported by the grants from the National Natural Science Foundation of China(No.22202098)the Natural Science Foundation of Henan Province(No.242300420199)。
文摘Heterogeneous catalysts have attracted wide attention due to their remarkable oxygen evolution reaction(OER)capabilities.Herein,a one-step strategy involving the coupling of NixSeywith CeO_(2)is proposed to concurrently construct heterogeneous interfaces,adjust phase structure,and regulate electronic configuration,thereby enhancing OER performance.Thanks to the role of CeO_(2)coupling in reducing the activation-energy and accelerating the reaction kinetics,the heterogeneous NixSey/CeO_(2)catalyst exhibits a low overpotential of 218 mV at 10 mA/cm2and long-term stability(>400 h)in 1.0 mol/L KOH for OER.Moreover,the post-OER characterization reveals that the NixSeymatrix is reconstructed into NiOOH,while the incorporated CeO_(2)nanocrystals self-assemble into larger polycrystalline particles.Theoretical analysis further demonstrates that the optimized electronic states at NiOOH/CeO_(2)interfaces can modulate intermediate chemisorption toward favorable OER kinetics.This study offers fresh perspectives on the synthesis and structure-activity relationship of CeO_(2)-coupled electrocatalysts.
基金supported by the Major Program(JD)of Hubei Province under Grant No.2023BAA009the National Natural Science Foundation of China(Grant No.22105162)+1 种基金the Natural Science Foundation of Hubei Province(Grant No.2023AFB623)the Original Exploration Seed Fund of Hubei University。
文摘Next-generation fire safety systems demand precise detection and motion recognition of flames.In-sensor computing,which integrates sensing,memory,and processing capabilities,has emerged as a key technology in flame detection.However,the implementation of hardware-level functional demonstrations based on artificial vision systems in the solar-blind ultraviolet(UV)band(200-280 nm)is hindered by the weak detection capability.Here,we propose Ga_(2)O_(3)/In_(2)Se_(3) heterojunctions for the ferroelectric(abbreviation:Fe)optoelectronic sensor(abbreviation:OES)array(5×5 pixels),which is capable of ultraweak UV light detection with an ultrahigh detectivity through ferroelectric regulation and features in configurable multimode functionality.The Fe-OES array can directly sense different flame motions and simulate the non-spiking gradient neurons of insect visual system.Moreover,the flame signal can be effectively amplified in combination with leaky integration-and-fire neuron hardware.Using this Fe-OES system and neuromorphic hardware,we successfully demonstrate three flame processing tasks:achieving efficient flame detection across all time periods with terminal and cloud-based alarms;flame motion recognition with a lightweight convolutional neural network achieving 96.47%accuracy;and flame light recognition with 90.51%accuracy by means of a photosensitive artificial neural system.This work provides effective tools and approaches for addressing a variety of complex flame detection tasks.
基金financially supported by the Sichuan Science and Technology Program (Grant No. 2025NSFSC0139)the China Postdoctoral Science Foundation (Grant No.2023MD734228)+10 种基金funding from Generalitat de Catalunya 2021SGR00457supported by MCIN with funding from European Union NextGenerationEU(PRTR-C17.I1)by Generalitat de Catalunya (In-CAEM Project)the support from the project AMaDE(PID2023-149158OB-C43)funded by MCIN/AEI/10.13039/501100011033/by “ERDF A way of making Europe”by the “European Union”supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.:CEX2021-001214-S)funded by the CERCA Programme/Generalitat de Catalunyaperformed in the framework of Universitat Autònoma de Barcelona Materials Science PhD programfunding from the CSC-UAB PhD scholarship program. ICN2 is founding member of e-DREAM[87]
文摘The methanol oxidation reaction(MOR)to formic acid offers a promising alternative to the anodic oxygen evolution reaction(OER)in water electrolysis.However,the development of efficient and cost-effective catalysts remains a primary challenge.In this study,an enhancement in catalytic MOR performance is achieved through the incorporation of Mn atoms with unsaturated t_(2g)orbitals into Ni_(3)Se_(4).Comprehensive experimental analyses and theoretical calculations reveal that substituting Ni with Mn induces strong electron-withdrawing effects,effectively modulating the local coordination environment of the metal centers.The presence of Mn also elongates Ni–Se(O)bonds,which reduces eg orbital occupancy and modifies the spin state of the material.Electrochemical measurements demonstrate that electrodes based on this optimized material exhibit a high spin state and deliver excellent catalytic activity,achieving a MOR current density up to∼190 mA cm^(−2)at 1.6 V.This performance enhancement is attributed to the favorable electronic configuration and reduced reaction energy barriers associated with the high-spin state.
基金supported by the National Natural Science Foundation of China(Grant No.52573299)the Natural Science Foundation of Jiangxi province(No.20242BAB25223,20232BCJ23025,20232BCJ25040,20232BAB214024)the Special Funding Program for Graduate Student Innovation of Jiangxi Province(No.YC2024-S594).
文摘Transition metal selenides as sodium-ion hybrid capacitor(SIHC)anodes still suffer from amorphization difficulties and capacity degradation triggered by polyselenide dissolution.Herein,an atomistic amorphous strategy is proposed to construct adjacent Nb-Nb diatomic pairs with Se/O-coordination(Se4-Nb2-O2)in N-doped carbon-confined amorphous selenide clusters(a-Nb-Se/O@NC).Synergistic carbon confinement and hydrothermal oxygenation induce amorphization of Nb–Se bonds,eliminating crystalline rigidity while creating isotropic dual-ion transport channels and high-density active sites enriched with dangling bonds,thereby enhancing structural integrity and Na+storage capacity.The unique Se/O-coordinated Nb-Nb diatomic configuration establishes an electron-delocalized system,where the low electronegativity of Se counterbalances electron withdrawal from coordinated O at Nb centers.These strengthen d-p orbital hybridization,reduce Na+adsorption energy,and optimize charge transfer pathways and reaction kinetics in the amorphous clusters.Electrochemical tests reveal that the a-Nb-Se/O@NC anode delivers a high reversible capacity of 312.57 mAh g^(−1)and exceptional cyclic stability(103%capacity retention)after 5000 cycles at 10.0 A g^(−1).Assembled SIHCs achieve outstanding energy/power densities(207.1 Wh kg^(−1)/18966 W kg^(−1)),surpassing most amorphous and crystalline counterparts.This work provides methodological insights for the design of electrodes in high-power storage devices through atomic modulation and electronic optimization of amorphous selenides.
基金financially supported by the National Natural Science Foundation of China(21922811,51702284,and 21878270)Zhejiang Provincial Natural Science Foundation of China(LR19B060002)the Startup Foundation for Hundred-Talent Program of Zhejiang University.
文摘Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.
基金Fundamental Research Funds for the Central Universities,Grant/Award Numbers:531118010111,531118010633National Natural Science Foundation of China,Grant/Award Numbers:22109041,52103313。
文摘The shell structure design has been recognized as a highly efficient strategy to buffer the severe volume expansion and consecutive pulverization of conversion-type anodes.Nevertheless,construction of a functional shell with a stabilized structure that meets the demands of both high electronic conductivity and feasible pathways for Na^(+)ions has been a challenge so far.Herein,we design a two-in-one shell configuration for bimetal selenides to achieve fast sodium storage within broadened voltage windows.The hybridized shell,which benefits from the combination of titanium dioxide quantum dots and amorphous carbon,can not only effectively buffer the strain and maintain structural integrity but also allow facile and reversible transport of electrons and Na^(+)uptake for electrode materials during sodiation/desodiation processes,resulting in increased reaction kinetics and diffusion of sodium ions,conferring many benefits to the functionality of conversion-type electrode materials.As a representative material,Ni-CoSe_(2) with such structural engineering shows a reversible capacity of 515 mAh g^(−1)at 0.1 A g^(−1)and a stable capacity of 416 mAh g^(−1)even at 6.4 A g^(−1);more than 80%of the capacity at 0.1 A g^(−1)could be preserved,so that this strategy holds great promise for designing fast-charging conversion-type anodes in the future.
基金the K.N.Toosi University of Technology Research Council for financial assistance
文摘Alkynyl selenides were prepared under very mild conditions by reacting terminal alkynes with respective diorganic diselenides in the presence of potassium t-butoxide. The advantages of this protocol include the use of readily available substrates and reagent and good yield of the products.
基金supported by the National Natural Science Foundation of China(Nos.51563002 and 52101243)the"100-level"Innovative Talents Project of Guizhou Province,China(No.[2016]5653)+1 种基金the Natural Science Foundation of Guangdong Province(No.2020A1515010886)the Science and Technology Planning Project of Guangzhou(No.202102010373)。
文摘Recently,metal selenides have obtained widespread attention as electrode materials for alkali(Li^(+)/Na^(+)/K^(+))batteries due to their promising theoretical capacity and mechanism.Nevertheless,metal selenides,similar to metal oxides and sulfides,also suffer from severe volume explosion during repeated charge/discharge processes,which results in the structure collapse and the following pulverization of electrode materials.Hence,it leads to poor cycle stability and influencing their further application.In order to solve these issues,some special strategies,including elemental doping,coupling with carbon materials,synthesis of the bimetal selenides with heterostructure,etc.,have been gradually applied to design novel electrode materials with outstanding electrochemical performance.Herein,the recent research progress on metal selenides as anodes for alkali ion batteries is summarized,including the regulation of crystal structure,synthesis strategies,modification methods,and electrochemical mechanisms and kinetics.Besides,the challenges of metal selenides and the perspective for future electrode material design are proposed.It is hoped to pave a way for the development of metal selenide electrode materials for the potential applications for alkali metal ion(Li^(+)/Na^(+)/K^(+))batteries.
基金financially supported by the Artificial Photosynthesis Project of the New Energy and Industrial Technology Development Organization(NEDO)Grant-in-Aids for Scientific Research(A)(No.16H02417)Young Scientists(A)(No.15H05494)from the Japan Society for the Promotion of Science(JSPS)
文摘Exploration of novel narrow bandgap semiconductors for overall water splitting is vital for the realization of practical solar H2 production.In the work,solid solutions of zinc selenide and copper gallium selenide with absorption edge wavelengths ranging from 480 to 730 nm were developed.Using these metal selenides as H2-evolving photocatalysts,CoOx/BiVO4 as the O2-evolving photocatalyst,and reduced graphene oxide as the electron mediator,all-solid-state Z-scheme overall pure water splitting systems were constructed.The rate of photocatalytic H2 evolution from aqueous solutions containing Na2S and Na2SO3 as the electron donors was evaluated while employing these selenide photocatalysts at various Zn/(Zn+Cu)and Ga/Cu molar ratios.The data demonstrate that efficient Z-scheme overall water splitting was significantly correlated to the photoelectrochemical performance of the selenide photocatalysts acting as photocathodes,rather than the photocatalytic activities of these materials during the sacrificial H2 evolution.
基金financially supported by the National Natural Science Foundation of China(Nos.52101243 and 51563002)the Natural Science Foundation of Guangdong Province(Nos.2020A1515010886 and 2021A1515010078)+1 种基金the Scientific and Technological Plan of Guangdong Province,China(No.2019B090905007)the Science and Technology Planning Project of Guangzhou(No.202102010373)。
文摘Bimetallic selenide with core-shell structure(CoSe_(2)/ZnSe/NC@ZnSe/NC)has been successfully prepared through facile carbonization and selenization processes of its core-shell metal-organic framework precursors,in which the precursor is synthesized by epitaxial growth of zinc-based zeolite imidazolate framework(ZIF-8)on the surface of cobalt-based and zinc-based zeolite imidazolate framework(ZIF-67@ZIF-8).The coreshell structure has the advantage of alleviating the volume expansion during repeated insertion and extraction of sodium ions which can effectively avoid structural collapse.Additionally,bimetallic selenides and heterostructure are effective strategies to greatly improve the rate capability of the material.Therefore,the core-shell structural CoSe2/ZnSe/NC@ZnSe/NC material can maintain the original dodecahedron structure and delivers a specific capacity of 308.6 mAh·g^(-1)at 1.0 A·g^(-1)after 300 cycles with the desirable capacity retention of 90%.With the synergistic effects of heterostructure and core-shell structure,CoSe_(2)/ZnSe/NC@ZnSe/NC exhibits better electrochemical performance than CoSe_(2)/ZnSe/NC and CoSe_(2)/NC.These prove that both core-shell structure and heterostructure have positive effects on improving the electrochemical properties of materials.
基金Natural Science Foundation of Hunan(No.2009NK3162)National Natural Science Foundation of China(No.21003040,20372020) for financial support
文摘In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive（Z）-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of（Z）-1-arylseleno-2-arylthio-1-alkene.
基金financially supported by the National Natural Science Foundation of China(No.52130101)the Project of Science and Technology Development Plan of Jilin Province in China(Nos.20210402058GH and 20220201114GX)。
文摘Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of LSBs.To solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb LiPSs.At the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction processes.The mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)calculations.The electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at 0.2C.And after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.
基金the Natural Science Foundation of the Education Commission of Jiangsu Province
文摘In the presence of BiCl3/Al or BiCl3/Fe, in THF-H2O, allylic (benzylic) bromides or α-bromoketones react with diorganyl diselenides to give allylic (benzylic) selenides orα-organylselenocarbonyl compounds respectively in moderate to good yields.
文摘Reduction of diaryldiselenides by the system of Cp2TiCl2/Bu'MgBr/THF gave the nucleophilic arylselenium complex. They reacted with diaryl iodonium salts to afford unsymmetrical diaryl selenides in high yields.
基金the National Natural Science Foundation of China (No.20462002)Natural Science Foundation of Jiangxi Province (No.2007GZW0172) for financial support.
文摘1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladiumcatalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic bromides.
基金the Natural Science Foundation of Jiangxi Province(No.0420017)for financial support
文摘A mild, one-pot procedure for the synthesis of vinyl ethers in good yields from 2-hydroxyalkyl phenyl selenides with primary or secondary organic halides has been developed.
