The utilization of nuclear power will persist as a prominent energy source in the foreseeable future.However,it presents substantial challenges concerning waste disposal and the potential emission of untreated radioac...The utilization of nuclear power will persist as a prominent energy source in the foreseeable future.However,it presents substantial challenges concerning waste disposal and the potential emission of untreated radioactive substances,such as radioactive 129I and 131I.The transportation of radioactive iodine poses a significant threat to both the environment and human health.Nevertheless,effectively,rapidly removing iodine ion from water using porous adsorbents remains a crucial challenge.In this work,three kinds of multiple sites porous organic polymers(POPs,POP-1,POP-2,and POP-3)have been developed using a monomer pre-modification strategy for highly efficient and fast I_(3) absorption from water.It is found that the POPs exhibited exceptional performance in terms of I3 adsorption,achieving a top-performing adsorption capacity of 5.25 g g^(-1) and the fastest average adsorption rate(K_(80%)=4.25 g g^(-1) h^(-1))with POP-1.Moreover,POP-1 exhibited exceptional capacity for the removal of I3 fromflowing aqueous solutions,with 95%removal efficiency observed even at 0.0005 mol L^(-1).Such results indicate that this material has the potential to be utilized for the emergency preparation of potable water in areas contaminated with radioactive iodine.The adsorption process can be effectively characterized by the Freundlich model and the pseudo-second-order model.The exceptional I_(3) absorption capacity is primarily attributed to the incorporation of a substantial number of active adsorption sites,including bromine,carbonyl,and amide groups.展开更多
Cubic boron arsenide(BAs)has attracted great attention due to its high thermal conductivity,however,its controllable,stable,and ideal preparation remains challenging.Herein,we investigated the effect of iodine-contain...Cubic boron arsenide(BAs)has attracted great attention due to its high thermal conductivity,however,its controllable,stable,and ideal preparation remains challenging.Herein,we investigated the effect of iodine-containing transport agents I_(2) and boron triiodide(BI_(3))on BAs synthesized and grown through chemical vapor transport.Results show that similar to the commonly used I_(2),BI_(3) accelerates the synthesis and improves the mass fraction of BAs from ~12% to over 90% at 820℃ and 1.5 MPa,a value beyond the promoting effect of only increasing temperature and pressure.Both agents enhance the quality of BAs crystals by reducing the full width at half maximum by up to 10%-20%.I_(2) agglomerates the grown crystals with twin defects(~50 nm wide),and BI_(3) improves the crystal anisotropy and element uniformity of BAs crystals with narrow twins(~15 nm wide)and increases the stoichiometry ratio(~0.990)to almost 1.Owing to the boron interstitials from the excessive boron supply,the spacing of layers in {111} increases to 0.286 nm in the presence of I_(2).Owing to its coordinated effect,BI_(3) only slightly influences the layer spacing at 0.275 nm,which is close to the theoretical value of 0.276 nm.In the chemical vapor transport,the anisotropic crystals with flat surfaces exhibit single-crystal characteristics under the action of BI_(3).Different from that of I_(2),the coordinated effect of BI_(3) can promote the efficient preparation of high-quality BAs crystal seeds and facilitate the advanced application of BAs.展开更多
Tetrahydrofuran ring can be opened with acyl chlorides or anhydrides catalyzed by gallium triiodides to afford iodo esters under mild conditions in good yields.
Carbon nanotubes(CNTs)have been far and wide employed as the counter electrodes(CEs)in dyesensitized solar cells because of their individual physical and chemical properties.However,the techniques available now,such a...Carbon nanotubes(CNTs)have been far and wide employed as the counter electrodes(CEs)in dyesensitized solar cells because of their individual physical and chemical properties.However,the techniques available now,such as chemical vapor deposition,arc discharge and laser ablation for synthesizing CNTs,commonly suffer from rigorous operations and complicated steps,which make the process difficult to be controlled.Herein,we present a simple and facile glutamic acid-assisted hydrothermal recrystallization strategy to construct bamboo-like CNTs(GHP-BC-x).Generally,the conventional organic dye3,4,9,10-perylene tetracarboxylic dianhydride(PTCDA)is used as a precursor and glutamic acid efficiently promotes the recrystallization of the perylene cores'planarπ-conjugated system in PTCDA under hydrothermal conditions and then self-assembles into one-dimensio nal nano rods with improved crystallization degree,finally resulting in the morphology of bamboo-like CNTs after carbonization.When applied as the counter electrodes,the GHP-BC-3 displays a remarkable power conversion efficiency of8.25%,benefiting from the superb electrical conductivity and mass transfer dynamics,superior to that of Pt CE(7.62%).展开更多
Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topologi...Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-πinteractions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts.展开更多
Diacetates 1 and N-[(1-benzotriazol-l-yl)alkyl]amides 2, both masked forms of aldehydes, could undergo deprotection and condensation with cycloalkanones in a one-pot procedure promoted by samarium(III) iodide (SmI3) ...Diacetates 1 and N-[(1-benzotriazol-l-yl)alkyl]amides 2, both masked forms of aldehydes, could undergo deprotection and condensation with cycloalkanones in a one-pot procedure promoted by samarium(III) iodide (SmI3) to afford α,α'-bis(substituted benzylidene) cycloalkanones in good yields.展开更多
Polyoxometalates(POMs)have been considered as an efficient catalyst for triiodide reduction in dye-sensitized solar cells(DSSCs).However,agglomeration of POMs limits the improvement in power conversion efficiency(PCE)...Polyoxometalates(POMs)have been considered as an efficient catalyst for triiodide reduction in dye-sensitized solar cells(DSSCs).However,agglomeration of POMs limits the improvement in power conversion efficiency(PCE)of DSSCs.In this paper,we improve our previous synthesis process by a simple ultrasonic driving strategy.A series of highly dispersed POM nanoparticles periodically deposited on multi-walled carbon nanotube(MWCNT)nanocomposites(abbreviated as POMs/CNTs)is synthesized,which increases the active sites by improving the dispersion degree and inhibiting the aggregation of POM molecules.Additionally,CNTs as a conductive support skeleton and physical barrier promote the rapid electron transfer and protect POM molecules from chemical degradation.The nanocomposites exhibit well-distributed morphology,and highly dispersed POM nanoparticles about tens of nanometers in diameter are in intimate contact with CNTs.Powder X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy and transmission electron microscopy demonstrate that POM nanoparticles have been periodically deposited on CNTs.POM/CNT counterelectrodes(CEs)exhibit a more remarkable performance towards triiodide reduction than pure CNT CEs,indicating that POMs deposited on CNTs boost electrocatalytic triiodide reduction.Among these POM/CNT CEs,the Co4PW9/CNT CE exhibits the best photovoltaic behavior with a high power conversion efficiency(PCE)of 7.60%,which is superior to that of the Pt CE(6.59%).The excellent activity originates from the synergistic effect between the high redox activity of POMs and the excellent conductive ability of CNTs.This work provides a foundation for preparing advanced high-efficient CE catalysts of POM materials.展开更多
Designing a noble-metal-free catalyst with the desired composition and structure is highly significant for accelerating the catalytic kinetics of the hydrogen evolution reaction(HER)and triiodide reduction reaction(IR...Designing a noble-metal-free catalyst with the desired composition and structure is highly significant for accelerating the catalytic kinetics of the hydrogen evolution reaction(HER)and triiodide reduction reaction(IRR),which is essential for advancing green hydrogen production from water electrolysis and improving the power conversion efficiency(PCE)of dye-sensitized solar cells(DSSCs).Herein,small-sized(1T,2H)phase MoS_(2)nanosheets were uniformly wrapped around an N-doped C dodecahedron(MoS_(2)@NC)through a continuous synthesis strategy with ZIF-8 serving as the original template.When MoS_(2)@NC is used as a catalyst for the HER,it only requires a low overpotential of 93 mV to reach 10 mA cm^(−2),surpassing most reported MoS_(2)-based catalysts.Furthermore,a device fabricated with MoS_(2)@NC achieves a PCE of 8.20%,which is comparable to that of a Pt-based one(8.59%).Theoretical calculations revealed that the enhanced HER activity of MoS_(2)@NC is mainly attributed to the enhanced water adsorption energy and a reduced energy barrier for overcoming the rate-determining step during the HER process.Additionally,the interfacial S sites in MoS_(2)@NC are responsible for the excellent catalytic activity in the IRR.The experimental and theoretical results collectively confirm that the as-designed MoS_(2)@NC is a promising bifunctional catalyst.展开更多
Quasimolecular layered metal triiodides MI_(3)(M=Sb and Bi)hold immense promise in applications of solid-state batteries,radiation detectors,and photocatalysts owing to their favorable physicochemical properties.As a ...Quasimolecular layered metal triiodides MI_(3)(M=Sb and Bi)hold immense promise in applications of solid-state batteries,radiation detectors,and photocatalysts owing to their favorable physicochemical properties.As a representative MI_(3) compound,antimony triiodide(SbI_(3))exhibits high-pressure phase stability beyond 16.0 GPa and its electrical transport behaviors remain largely unknown.In this study,we systemically investigated the structural and electronic transitions of SbI_(3)during compression and decompression under different hydrostatic environments using synchrotron X-ray diffraction,Raman spectroscopy,electrical conductivity,and first-principles theoretical calculations.During compression,SbI_(3)endured two isostructural phase transitions(IPTs)at the respective pressures of 3.4 GPa and 10.3 GPa stemming from the prominent compression of the c-axis and Sb-I bond.Upon further compression to 32.3 GPa,an electronic transition from the semiconductor to metal occurred in SbI_(3)under non-hydrostatic conditions,which was possibly associated with the rhombohedral(R)-to-monoclinic(C_(2)/m)structural transformation.Under hydrostatic conditions,a considerable pressure hysteresis of∼5.0 GPa was detected for the emergence of metallization owing to the faint deviatoric stress.During decompression,the phase transition of SbI_(3)was revealed to be irreversible under different hydrostatic environments,which was probably caused by the huge kinetic barrier for the continuous high-pressure structural transitions.Our high-pressure study on SbI_(3)offers an in-depth insight into the correlations between crystalline and electronic structures,and may facilitate the application of quasimolecular layered crystals in optoelectronic devices.展开更多
Developing low-cost,efficient and flexible electrocatalysts is an important approach to promote the commercialization of dye-sensitized solar cells(DSSCs).Herein,we utilized a simple and mild H_(2)O_(2) etching strate...Developing low-cost,efficient and flexible electrocatalysts is an important approach to promote the commercialization of dye-sensitized solar cells(DSSCs).Herein,we utilized a simple and mild H_(2)O_(2) etching strategy to introduce Mo vacancies on the surface of the MoS_(2) thin film and induce a crystal phase change from 2H to 1T.By systematically adjusting the etching time,temperature,and solution concentration,the optimal concentration of Mo vacancies was achieved.As a result,the optimized flexible CE(MoS_(2)-60 s)exhibited the highest power conversion efficiency(4.45%),which was increased by 33.24% compared to the untreated MoS_(2) sample.Moreover,the PCE of MoS_(2)-60 s CE under simulated indoor light irradiation(1000 lux)was 24.33%,demonstrating its advantages for indoor PV applications.The above data proved the effectiveness of the strategy for regulating vacancies and phase changes induced by etching,especially in indoor low-light environments.Furthermore,the prepared flexible MoS_(2)-60 s CE also exhibited prominent electrochemical stability,bending durability and uniform electrocatalytic activity with a size of 4.5×5 cm.The significantly enhanced performance was mainly attributed to the synergistic effect of Mo vacancies and phase change.Moreover,the transmittance of the MoS_(2) CE after etching was significantly improved,showing potential for application in transparent DSSCs.In this article,the CE with high responsiveness to simulated indoor light,good stability,flexibility and transparency was prepared,which expands the application scenarios of DSSCs and promotes their commercial application.展开更多
Heterogeneous metal atom doping is considered as an effective strategy to boost catalytic activity through the coordinated modulation of metal active sites and the electronic structure,which is also beneficial for est...Heterogeneous metal atom doping is considered as an effective strategy to boost catalytic activity through the coordinated modulation of metal active sites and the electronic structure,which is also beneficial for establishing the relationship between structure and performance in energy conversion devices.Herein,we developed Mo-doped NiSe hierarchical microspheres with different Mo doping amounts by a simple solvothermal method.DFT calculation results including the more appropriate adsorption energy for adsorption of I_(3)^(-),the further elongated I_(1)-I_(2)bond length of I_(3)^(-),and efficient interaction between metal 3d and I 5p states collectively indicated that the catalytic activity for the IRR can be significantly enhanced by doping molybdenum in NiSe.Subsequently,dye-sensitized solar cells(DSSCs)fabricated with the optimized Mo_(0.10)-NiSe display a remarkable power conversion efficiency of 8.92%,superior to that of the Mo_(0.05)-NiSe(8.40%),Mo_(0.15)-NiSe(8.62%),NiSe(7.51%),and Pt-based devices(7.74%)in comparison.The impressive performance endows Mo_(0.10)-NiSe with a new opportunity to achieve the substitution of noble Pt in low-cost DSSCs.展开更多
Hierarchical Pt-alloys enriched with active sites are highly desirable for efficient catalysis,but their syntheses generally need time-consuming and elaborate annealing treatment at high temperature.We herein report a...Hierarchical Pt-alloys enriched with active sites are highly desirable for efficient catalysis,but their syntheses generally need time-consuming and elaborate annealing treatment at high temperature.We herein report a surface active-site engineering strategy for constructing the hierarchical PtNi nanocatalysts with an atomic Pt-skin layer(PtNi@Pt-SL)towards efficient triiodide reduction reaction(TRR)via an acid-dealloying approach.The facile acid-dealloying process promotes the formation of surface Pt active sites on the hierarchical Pt-alloys,and thus results in good catalytic performance towards TRR.Theoretical calculation reveals that the enhanced catalytic property stems from the moderate energy barriers for iodide atoms on the surface Pt active-sites.The surface active-site engineering strategy paves a new way for the design of active and durable electrocatalysts.展开更多
Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon ...Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon nanotubes(SWCNTs)with excellent electrical properties and high stability have been studied as active materials for synaptic devices.However,the performance of optical synaptic devices(OSDs)based on pure SWCNTs is limited by the weak light absorption property.Herein,bismuth triiodide(BiI_(3)),an environmentally stable and friendly optoelectronic material,is firstly combined with SWCNTs to fabricate OSDs with decent properties of perceiving and memorizing optical information.The OSDs can exhibit typical synaptic behaviors including excitatory postsynaptic current,paired-pulse facilitation,and short/long-term memory.Distinctively,the photoresponse of the OSD is independent of pulse light wavelength in the range of 365 to 650 nm,different from most of the previously reported OSDs,which usually have wavelength-dependent photo-response.Temperature-dependent photo-response behaviors of the devices are investigated.Importantly,the OSD without encapsulation holds good excitatory post-synaptic current(EPSC)behavior after being stored in the ambient environment for 170 days,indicating reliable environmental stability.Furthermore,an OSD array with nine synaptic devices is employed to mimic the human visual perception and memory functions.These results suggest the feasibility of BiI3/SWCNTs-based OSDs for the simulation of human visual memory.展开更多
Linearly bonded triiodide chains with fairly small distance between the adjacent iodine ions feature a facile electron transfer and highly anisotropic properties.Here,we demonstrate a novel strategy towards a new one-...Linearly bonded triiodide chains with fairly small distance between the adjacent iodine ions feature a facile electron transfer and highly anisotropic properties.Here,we demonstrate a novel strategy towards a new one-dimensional linear triiodide DMEDA·I6,using chain-type N,N'-dimethylethanediamine(DMEDA)cation to coordinate triiodine ions.This triiodide has the shortest distance between adjacent I3^- and good linearity.An estimated electronic band gap of1.36 e V indicates its semiconducting properties.100 fold differences both in polarization-sensitive absorption and effective mass were achieved by simulation,with directions parallel and perpendicular to the a-axis of DMEDA·I6.The DMEDA·I6 single crystal-based photodetectors show a good switching characteristic and a distinct polarization-sensitive photoresponse with linear dichroic photodetection ratio of about 1.9.Strongly anisotropic features and semiconducting properties of DMEDA·I6 make this triiodide system an interesting candidate for polarization related applications.展开更多
The nanocomposites of cobalt selenide and nickel selenide(Co_(0.85)Se/Ni_(0.85)Se)were successfully fabricated on FTO glass by a facile co-electrodeposition method at ambient temperature.Nanocomposite films were used ...The nanocomposites of cobalt selenide and nickel selenide(Co_(0.85)Se/Ni_(0.85)Se)were successfully fabricated on FTO glass by a facile co-electrodeposition method at ambient temperature.Nanocomposite films were used as elec-trocatalysts in dye-sensitized solar cell counter electrodes for regeneration of both iodide/triiodide and cobalt(II/III)redox couples.Co_(0.85)Se/Ni_(0.85)Se were mainly composed of nanoflakes and nanoparticles.It is noted that such nanostructure generated by nanoparticles embedded with 2D nanoflakes led to high active sites and was accessible to cobalt(II/III)electrolyte,delivering better catalytic activity for the reduction of larger volume cobalt(II/III).As a result,for cobalt(II/III)electrolyte,the Co_(0.85)Se/Ni_(0.85)Se based dye-sensitized solar cell performed significantly im-proved efficiency than that of Pt and Co_(0.85)Se.Meanwhile,the Co_(0.85)Se/Ni_(0.85)Se based dye-sensitized solar cell held comparable energy conversion efficiency to that of Pt and Co_(0.85)Se for iodide/triiodide electrolyte.展开更多
Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limi...Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limits its practical applications,highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties.In this study,we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI_(3)phases.Our structural predictions identify two novel polymorphs with Cm and P2/m space groups,both of which are dynamically stable and exhibit significantly higher T_(C)values of 145 K and 81 K,respectively.Electronic property calculations show that the Cm phase is a half-metal,while the P2/m phase is semiconducting with a bandgap of 0.14 eV.Monte Carlo simulations attribute these enhanced T_(C)values to a notable increase in exchange interactions.These findings expand the known phase space of CrI_(3)and provide a promising pathway for designing hightemperature 2D ferromagnets for next-generation spintronic applications.展开更多
Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3)...Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3) nanobelts via a solution process.A single-crystalline CsPbI_(3) nanobelt with uniform morphology can be achieved by controlling the amount of PbI_(2).A single-crystalline CsPbI_(3) nanobelt possesses a mean width,length,and thickness of 100 nm,5μm,and 20 nm,respectively.In this work,photodetectors(PDs)based on individual CsPbI_(3) nanobelts are constructed and found to perform well with an external quantum efficiency and responsivity of 2.39×10^(5)% and 770 A/W,respectively.The PDs also show a high detectivity of up to 3.12×10^(12) Jones,which is at par with that of Si PDs.The PDs developed in this work exhibit great promise in various optoelectronic nanodevices.展开更多
A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions...A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions and have been extensively employed to manipulate the growth of perovskite crystals.In this work,we demonstrate a series of Lewis-base amides,for morphological regulation of methylammonium lead triiodide(MAPbI3)thin films.The screened acetamide was demonstrated to decently improve the grain size,along with a spatial distribution at grain boundaries(GBs).The mesostructured solar cells of acetamide-modified absorbers yielded an optimized power conversion efficiency(PCE)of 20.04%with a mitigated open-circuit voltage(V_(OC))deficit of 0.39 V.This work provides a facile and cost-effective strategy toward controllable fabrication of high-performance MAPbI3 solar cells.展开更多
Stereoselective transformation of Baylis-Hillman acetates I into corresponding （Z）-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodi...Stereoselective transformation of Baylis-Hillman acetates I into corresponding （Z）-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate （[bmim]BF4） was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford （Z）-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.展开更多
One-pot reaction of aldehydes, ?haloketones and (phenylsulfonyl)acetonitrile promoted by SmI3 proceeded smoothly to give 1-cyano-1-phenylsulfonyl-2-aryl-3-aroyl-propane derivatives in moderate to good yields.
基金support from the National Natural Science Foundation of China(No.22273016,22273017,22233006)Plan for Henan Province University Science and Technology Innovation Team(No.25IRTSTHN002)+1 种基金Young Backbone Teacher Training Program of Henan Province(2023GGJS036)the 111 project(No.D17007).
文摘The utilization of nuclear power will persist as a prominent energy source in the foreseeable future.However,it presents substantial challenges concerning waste disposal and the potential emission of untreated radioactive substances,such as radioactive 129I and 131I.The transportation of radioactive iodine poses a significant threat to both the environment and human health.Nevertheless,effectively,rapidly removing iodine ion from water using porous adsorbents remains a crucial challenge.In this work,three kinds of multiple sites porous organic polymers(POPs,POP-1,POP-2,and POP-3)have been developed using a monomer pre-modification strategy for highly efficient and fast I_(3) absorption from water.It is found that the POPs exhibited exceptional performance in terms of I3 adsorption,achieving a top-performing adsorption capacity of 5.25 g g^(-1) and the fastest average adsorption rate(K_(80%)=4.25 g g^(-1) h^(-1))with POP-1.Moreover,POP-1 exhibited exceptional capacity for the removal of I3 fromflowing aqueous solutions,with 95%removal efficiency observed even at 0.0005 mol L^(-1).Such results indicate that this material has the potential to be utilized for the emergency preparation of potable water in areas contaminated with radioactive iodine.The adsorption process can be effectively characterized by the Freundlich model and the pseudo-second-order model.The exceptional I_(3) absorption capacity is primarily attributed to the incorporation of a substantial number of active adsorption sites,including bromine,carbonyl,and amide groups.
基金financially supported by the National Key R&D Program of China(Nos.2018YFC1900302 and 2020YFC1909201)the National Science Fund for Distinguished Young Scholars(No.51825403)。
文摘Cubic boron arsenide(BAs)has attracted great attention due to its high thermal conductivity,however,its controllable,stable,and ideal preparation remains challenging.Herein,we investigated the effect of iodine-containing transport agents I_(2) and boron triiodide(BI_(3))on BAs synthesized and grown through chemical vapor transport.Results show that similar to the commonly used I_(2),BI_(3) accelerates the synthesis and improves the mass fraction of BAs from ~12% to over 90% at 820℃ and 1.5 MPa,a value beyond the promoting effect of only increasing temperature and pressure.Both agents enhance the quality of BAs crystals by reducing the full width at half maximum by up to 10%-20%.I_(2) agglomerates the grown crystals with twin defects(~50 nm wide),and BI_(3) improves the crystal anisotropy and element uniformity of BAs crystals with narrow twins(~15 nm wide)and increases the stoichiometry ratio(~0.990)to almost 1.Owing to the boron interstitials from the excessive boron supply,the spacing of layers in {111} increases to 0.286 nm in the presence of I_(2).Owing to its coordinated effect,BI_(3) only slightly influences the layer spacing at 0.275 nm,which is close to the theoretical value of 0.276 nm.In the chemical vapor transport,the anisotropic crystals with flat surfaces exhibit single-crystal characteristics under the action of BI_(3).Different from that of I_(2),the coordinated effect of BI_(3) can promote the efficient preparation of high-quality BAs crystal seeds and facilitate the advanced application of BAs.
基金the National Natural Science Foundation of China !298720I0the NSF of she-hang Provincethe Laboratory of Organometallic Ch
文摘Tetrahydrofuran ring can be opened with acyl chlorides or anhydrides catalyzed by gallium triiodides to afford iodo esters under mild conditions in good yields.
基金partly supported by the National Natural Science Foundation of China(51872035 and 22078052)Talent Program of Rejuvenation of the Liaoning(XLYC1807002)Innovation Program of Dalian City(2019RJ03)。
文摘Carbon nanotubes(CNTs)have been far and wide employed as the counter electrodes(CEs)in dyesensitized solar cells because of their individual physical and chemical properties.However,the techniques available now,such as chemical vapor deposition,arc discharge and laser ablation for synthesizing CNTs,commonly suffer from rigorous operations and complicated steps,which make the process difficult to be controlled.Herein,we present a simple and facile glutamic acid-assisted hydrothermal recrystallization strategy to construct bamboo-like CNTs(GHP-BC-x).Generally,the conventional organic dye3,4,9,10-perylene tetracarboxylic dianhydride(PTCDA)is used as a precursor and glutamic acid efficiently promotes the recrystallization of the perylene cores'planarπ-conjugated system in PTCDA under hydrothermal conditions and then self-assembles into one-dimensio nal nano rods with improved crystallization degree,finally resulting in the morphology of bamboo-like CNTs after carbonization.When applied as the counter electrodes,the GHP-BC-3 displays a remarkable power conversion efficiency of8.25%,benefiting from the superb electrical conductivity and mass transfer dynamics,superior to that of Pt CE(7.62%).
基金partly supported by the National Natural Science Foundation of China(22078052)the National Key R&D Program of China(2022YFB4101602)the Fundamental Research Funds for the Central Universities(DUT22LAB612)。
文摘Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-πinteractions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts.
文摘Diacetates 1 and N-[(1-benzotriazol-l-yl)alkyl]amides 2, both masked forms of aldehydes, could undergo deprotection and condensation with cycloalkanones in a one-pot procedure promoted by samarium(III) iodide (SmI3) to afford α,α'-bis(substituted benzylidene) cycloalkanones in good yields.
基金financially supported by the National Natural Science Foundation of China(No.21871041 and 21801038)the Natural Science Foundation of Jilin Province(No.20180101298JC)+3 种基金the China Postdoctoral Science Foundation funded project(No.2019T120227)the Technology Foundation for Selected Overseas Chinese Scholars of Personnel Ministry of ChinaScience and Technology Activities Project Preferential Funding for Selected Overseas Chinese Scholars of Jilin Province Human Resources and Social BureauHigh Tech Industry Innovation Project of Changchun Northeast Normal University Science and Technology Development Center.
文摘Polyoxometalates(POMs)have been considered as an efficient catalyst for triiodide reduction in dye-sensitized solar cells(DSSCs).However,agglomeration of POMs limits the improvement in power conversion efficiency(PCE)of DSSCs.In this paper,we improve our previous synthesis process by a simple ultrasonic driving strategy.A series of highly dispersed POM nanoparticles periodically deposited on multi-walled carbon nanotube(MWCNT)nanocomposites(abbreviated as POMs/CNTs)is synthesized,which increases the active sites by improving the dispersion degree and inhibiting the aggregation of POM molecules.Additionally,CNTs as a conductive support skeleton and physical barrier promote the rapid electron transfer and protect POM molecules from chemical degradation.The nanocomposites exhibit well-distributed morphology,and highly dispersed POM nanoparticles about tens of nanometers in diameter are in intimate contact with CNTs.Powder X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy and transmission electron microscopy demonstrate that POM nanoparticles have been periodically deposited on CNTs.POM/CNT counterelectrodes(CEs)exhibit a more remarkable performance towards triiodide reduction than pure CNT CEs,indicating that POMs deposited on CNTs boost electrocatalytic triiodide reduction.Among these POM/CNT CEs,the Co4PW9/CNT CE exhibits the best photovoltaic behavior with a high power conversion efficiency(PCE)of 7.60%,which is superior to that of the Pt CE(6.59%).The excellent activity originates from the synergistic effect between the high redox activity of POMs and the excellent conductive ability of CNTs.This work provides a foundation for preparing advanced high-efficient CE catalysts of POM materials.
基金support from the National Natural Science Foundation of China(22005161)the Fundamental Research Funds in Heilongjiang Provincial Universities of China(145309204)the College Students’Innovative Entrepreneurial Training Plan Program(S202410232134).
文摘Designing a noble-metal-free catalyst with the desired composition and structure is highly significant for accelerating the catalytic kinetics of the hydrogen evolution reaction(HER)and triiodide reduction reaction(IRR),which is essential for advancing green hydrogen production from water electrolysis and improving the power conversion efficiency(PCE)of dye-sensitized solar cells(DSSCs).Herein,small-sized(1T,2H)phase MoS_(2)nanosheets were uniformly wrapped around an N-doped C dodecahedron(MoS_(2)@NC)through a continuous synthesis strategy with ZIF-8 serving as the original template.When MoS_(2)@NC is used as a catalyst for the HER,it only requires a low overpotential of 93 mV to reach 10 mA cm^(−2),surpassing most reported MoS_(2)-based catalysts.Furthermore,a device fabricated with MoS_(2)@NC achieves a PCE of 8.20%,which is comparable to that of a Pt-based one(8.59%).Theoretical calculations revealed that the enhanced HER activity of MoS_(2)@NC is mainly attributed to the enhanced water adsorption energy and a reduced energy barrier for overcoming the rate-determining step during the HER process.Additionally,the interfacial S sites in MoS_(2)@NC are responsible for the excellent catalytic activity in the IRR.The experimental and theoretical results collectively confirm that the as-designed MoS_(2)@NC is a promising bifunctional catalyst.
基金financially supported by the NSF of China(grant numbers 42072055,42274137 and 42302047).
文摘Quasimolecular layered metal triiodides MI_(3)(M=Sb and Bi)hold immense promise in applications of solid-state batteries,radiation detectors,and photocatalysts owing to their favorable physicochemical properties.As a representative MI_(3) compound,antimony triiodide(SbI_(3))exhibits high-pressure phase stability beyond 16.0 GPa and its electrical transport behaviors remain largely unknown.In this study,we systemically investigated the structural and electronic transitions of SbI_(3)during compression and decompression under different hydrostatic environments using synchrotron X-ray diffraction,Raman spectroscopy,electrical conductivity,and first-principles theoretical calculations.During compression,SbI_(3)endured two isostructural phase transitions(IPTs)at the respective pressures of 3.4 GPa and 10.3 GPa stemming from the prominent compression of the c-axis and Sb-I bond.Upon further compression to 32.3 GPa,an electronic transition from the semiconductor to metal occurred in SbI_(3)under non-hydrostatic conditions,which was possibly associated with the rhombohedral(R)-to-monoclinic(C_(2)/m)structural transformation.Under hydrostatic conditions,a considerable pressure hysteresis of∼5.0 GPa was detected for the emergence of metallization owing to the faint deviatoric stress.During decompression,the phase transition of SbI_(3)was revealed to be irreversible under different hydrostatic environments,which was probably caused by the huge kinetic barrier for the continuous high-pressure structural transitions.Our high-pressure study on SbI_(3)offers an in-depth insight into the correlations between crystalline and electronic structures,and may facilitate the application of quasimolecular layered crystals in optoelectronic devices.
基金supported by the Basic Scientific Research Funds for Universities Affiliated to Hebei Province of China(KY2023019)Special Program for Talent Introduction of Hebei Agricultural University(YJ201928)+2 种基金Open Foundation of Key Laboratory for UV-Emitting Materials and Technology of Ministry of Education,Northeast Normal University(135131009)Jilin Scientific and Technological Development Program(20230101110JC)Natural Science Foundation of China(62074031).
文摘Developing low-cost,efficient and flexible electrocatalysts is an important approach to promote the commercialization of dye-sensitized solar cells(DSSCs).Herein,we utilized a simple and mild H_(2)O_(2) etching strategy to introduce Mo vacancies on the surface of the MoS_(2) thin film and induce a crystal phase change from 2H to 1T.By systematically adjusting the etching time,temperature,and solution concentration,the optimal concentration of Mo vacancies was achieved.As a result,the optimized flexible CE(MoS_(2)-60 s)exhibited the highest power conversion efficiency(4.45%),which was increased by 33.24% compared to the untreated MoS_(2) sample.Moreover,the PCE of MoS_(2)-60 s CE under simulated indoor light irradiation(1000 lux)was 24.33%,demonstrating its advantages for indoor PV applications.The above data proved the effectiveness of the strategy for regulating vacancies and phase changes induced by etching,especially in indoor low-light environments.Furthermore,the prepared flexible MoS_(2)-60 s CE also exhibited prominent electrochemical stability,bending durability and uniform electrocatalytic activity with a size of 4.5×5 cm.The significantly enhanced performance was mainly attributed to the synergistic effect of Mo vacancies and phase change.Moreover,the transmittance of the MoS_(2) CE after etching was significantly improved,showing potential for application in transparent DSSCs.In this article,the CE with high responsiveness to simulated indoor light,good stability,flexibility and transparency was prepared,which expands the application scenarios of DSSCs and promotes their commercial application.
基金support of the National Natural Science Foundation of China(22005161)the Fundamental Research Funds in Heilongjiang Provincial Universities of China(145109209)the Heilongjiang Provincial Key Laboratory of Surface Active Agent and Auxiliary(BMHXJKF006).
文摘Heterogeneous metal atom doping is considered as an effective strategy to boost catalytic activity through the coordinated modulation of metal active sites and the electronic structure,which is also beneficial for establishing the relationship between structure and performance in energy conversion devices.Herein,we developed Mo-doped NiSe hierarchical microspheres with different Mo doping amounts by a simple solvothermal method.DFT calculation results including the more appropriate adsorption energy for adsorption of I_(3)^(-),the further elongated I_(1)-I_(2)bond length of I_(3)^(-),and efficient interaction between metal 3d and I 5p states collectively indicated that the catalytic activity for the IRR can be significantly enhanced by doping molybdenum in NiSe.Subsequently,dye-sensitized solar cells(DSSCs)fabricated with the optimized Mo_(0.10)-NiSe display a remarkable power conversion efficiency of 8.92%,superior to that of the Mo_(0.05)-NiSe(8.40%),Mo_(0.15)-NiSe(8.62%),NiSe(7.51%),and Pt-based devices(7.74%)in comparison.The impressive performance endows Mo_(0.10)-NiSe with a new opportunity to achieve the substitution of noble Pt in low-cost DSSCs.
基金The research was financially supported by the National Natural Science Foundation of China(No.21771019)the National Key Research and Development Program of China(No.2018YFA0702002)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.XK1901 and buctrc202023)P.Ma is funded by China Postdoctoral Science Foundation(No.2020M672772)。
文摘Hierarchical Pt-alloys enriched with active sites are highly desirable for efficient catalysis,but their syntheses generally need time-consuming and elaborate annealing treatment at high temperature.We herein report a surface active-site engineering strategy for constructing the hierarchical PtNi nanocatalysts with an atomic Pt-skin layer(PtNi@Pt-SL)towards efficient triiodide reduction reaction(TRR)via an acid-dealloying approach.The facile acid-dealloying process promotes the formation of surface Pt active sites on the hierarchical Pt-alloys,and thus results in good catalytic performance towards TRR.Theoretical calculation reveals that the enhanced catalytic property stems from the moderate energy barriers for iodide atoms on the surface Pt active-sites.The surface active-site engineering strategy paves a new way for the design of active and durable electrocatalysts.
基金supported by the National Natural Science Foundation of China(Nos.61822405,62074111)the Science&Technology Foundation of Shanghai(Nos.19JC1412402,20JC1415600)+2 种基金Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)Shanghai Municipal Commission of Science and Technology Project(No.19511132101)the support of the Fundamental Research Funds for the Central Universities.
文摘Artificial synaptic devices with the functions of emulating important biological synaptic behaviors are playing an increasingly important role in the development of neuromorphic computing systems.Single-walled carbon nanotubes(SWCNTs)with excellent electrical properties and high stability have been studied as active materials for synaptic devices.However,the performance of optical synaptic devices(OSDs)based on pure SWCNTs is limited by the weak light absorption property.Herein,bismuth triiodide(BiI_(3)),an environmentally stable and friendly optoelectronic material,is firstly combined with SWCNTs to fabricate OSDs with decent properties of perceiving and memorizing optical information.The OSDs can exhibit typical synaptic behaviors including excitatory postsynaptic current,paired-pulse facilitation,and short/long-term memory.Distinctively,the photoresponse of the OSD is independent of pulse light wavelength in the range of 365 to 650 nm,different from most of the previously reported OSDs,which usually have wavelength-dependent photo-response.Temperature-dependent photo-response behaviors of the devices are investigated.Importantly,the OSD without encapsulation holds good excitatory post-synaptic current(EPSC)behavior after being stored in the ambient environment for 170 days,indicating reliable environmental stability.Furthermore,an OSD array with nine synaptic devices is employed to mimic the human visual perception and memory functions.These results suggest the feasibility of BiI3/SWCNTs-based OSDs for the simulation of human visual memory.
基金financially supported by the National Natural Science Foundation of China (51761145048, 61725401 and 61704097)the Innovation Fund of WNLO and the 62th China Postdoctoral Science Foundation (2017M622418)
文摘Linearly bonded triiodide chains with fairly small distance between the adjacent iodine ions feature a facile electron transfer and highly anisotropic properties.Here,we demonstrate a novel strategy towards a new one-dimensional linear triiodide DMEDA·I6,using chain-type N,N'-dimethylethanediamine(DMEDA)cation to coordinate triiodine ions.This triiodide has the shortest distance between adjacent I3^- and good linearity.An estimated electronic band gap of1.36 e V indicates its semiconducting properties.100 fold differences both in polarization-sensitive absorption and effective mass were achieved by simulation,with directions parallel and perpendicular to the a-axis of DMEDA·I6.The DMEDA·I6 single crystal-based photodetectors show a good switching characteristic and a distinct polarization-sensitive photoresponse with linear dichroic photodetection ratio of about 1.9.Strongly anisotropic features and semiconducting properties of DMEDA·I6 make this triiodide system an interesting candidate for polarization related applications.
基金This work was supported by the National Program on Key Basic Research Project of China(973 Program)(No.MOST2011CB935700)the National Natural Sci-ence Foundation of China(Nos.21202178,21271180)the Shandong Province Natural Science Foundation(Nos.ZR2011BQ024,ZR2013FZ001 and ZR2010BM016).
文摘The nanocomposites of cobalt selenide and nickel selenide(Co_(0.85)Se/Ni_(0.85)Se)were successfully fabricated on FTO glass by a facile co-electrodeposition method at ambient temperature.Nanocomposite films were used as elec-trocatalysts in dye-sensitized solar cell counter electrodes for regeneration of both iodide/triiodide and cobalt(II/III)redox couples.Co_(0.85)Se/Ni_(0.85)Se were mainly composed of nanoflakes and nanoparticles.It is noted that such nanostructure generated by nanoparticles embedded with 2D nanoflakes led to high active sites and was accessible to cobalt(II/III)electrolyte,delivering better catalytic activity for the reduction of larger volume cobalt(II/III).As a result,for cobalt(II/III)electrolyte,the Co_(0.85)Se/Ni_(0.85)Se based dye-sensitized solar cell performed significantly im-proved efficiency than that of Pt and Co_(0.85)Se.Meanwhile,the Co_(0.85)Se/Ni_(0.85)Se based dye-sensitized solar cell held comparable energy conversion efficiency to that of Pt and Co_(0.85)Se for iodide/triiodide electrolyte.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFA1610000)the National Natural Science Foundation of China(Grant Nos.12304036 and 12304265)+1 种基金the Basic and Applied Basic Research Foundation of Guangdong Province,China(Grant No.2023A1515010071)the Fundamental Research Funds for the Central Universities to Sun Yat-sen University(Grant No.23xkjc016).
文摘Monolayer CrI_(3),crystalizing in the P31m space group,is a prototypical two-dimensional(2D)material for observing intrinsic ferromagnetic order.However,its relatively low Curie temperature(T_(C))of 45 K severely limits its practical applications,highlighting the need to explore novel metastable polymorphs with enhanced magnetic properties.In this study,we employ a global crystal structure search technique combined with first-principles calculations to systematically investigate new monolayer CrI_(3)phases.Our structural predictions identify two novel polymorphs with Cm and P2/m space groups,both of which are dynamically stable and exhibit significantly higher T_(C)values of 145 K and 81 K,respectively.Electronic property calculations show that the Cm phase is a half-metal,while the P2/m phase is semiconducting with a bandgap of 0.14 eV.Monte Carlo simulations attribute these enhanced T_(C)values to a notable increase in exchange interactions.These findings expand the known phase space of CrI_(3)and provide a promising pathway for designing hightemperature 2D ferromagnets for next-generation spintronic applications.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51974021 and 51902020)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-18-045A1 and FRF-TP-19-004B2Z)+1 种基金the National Postdoctoral Program for Innovative Talents(BX20180034)the China Postdoctoral Science Foundation(Grant No.2018M641192).
文摘Lead halide perovskites have received increasing attention recently as a candidate material in various optoelectronic areas because of their high performance as light absorbers.Herein,we report the growth of CsPbI_(3) nanobelts via a solution process.A single-crystalline CsPbI_(3) nanobelt with uniform morphology can be achieved by controlling the amount of PbI_(2).A single-crystalline CsPbI_(3) nanobelt possesses a mean width,length,and thickness of 100 nm,5μm,and 20 nm,respectively.In this work,photodetectors(PDs)based on individual CsPbI_(3) nanobelts are constructed and found to perform well with an external quantum efficiency and responsivity of 2.39×10^(5)% and 770 A/W,respectively.The PDs also show a high detectivity of up to 3.12×10^(12) Jones,which is at par with that of Si PDs.The PDs developed in this work exhibit great promise in various optoelectronic nanodevices.
基金financially supported by the National Natural Science Funds for Distinguished Young Scholar(51725201)the National Natural Science Foundation of China(51972111,51902185,51602103)+4 种基金Young Elite Scientists Sponsorship Program by CAST(2017QNRC001)International(Regional)Cooperation and Exchange Projects of the National Natural Science Foundation of China(51920105003)Innovation Program of Shanghai Municipal Education Commission(E00014)the Fundamental Research Funds for the Central Universities(JKD012016025,JKD012016022)Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)。
文摘A controllable crystallization is of practical importance to produce high-quality perovskite thin films with reduced structural defects.Lewis bases as electron-pair donor chemicals can strongly coordinate to lead ions and have been extensively employed to manipulate the growth of perovskite crystals.In this work,we demonstrate a series of Lewis-base amides,for morphological regulation of methylammonium lead triiodide(MAPbI3)thin films.The screened acetamide was demonstrated to decently improve the grain size,along with a spatial distribution at grain boundaries(GBs).The mesostructured solar cells of acetamide-modified absorbers yielded an optimized power conversion efficiency(PCE)of 20.04%with a mitigated open-circuit voltage(V_(OC))deficit of 0.39 V.This work provides a facile and cost-effective strategy toward controllable fabrication of high-performance MAPbI3 solar cells.
基金Project (No. 2004C21032) supported by the Key Technology R & DProgram of Zhejiang Province, China
文摘Stereoselective transformation of Baylis-Hillman acetates I into corresponding （Z）-allyl iodides 2 has been achieved by treatment of I with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate （[bmim]BF4） was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford （Z）-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.
基金the National Natural Science Foundation of China(Project No.20072033)the NSF of Zhejiang Province,China for financial support
文摘One-pot reaction of aldehydes, ?haloketones and (phenylsulfonyl)acetonitrile promoted by SmI3 proceeded smoothly to give 1-cyano-1-phenylsulfonyl-2-aryl-3-aroyl-propane derivatives in moderate to good yields.
