化学“101计划”基础化学实验课程建设的思考与实践

化学“101计划”基础化学实验课程适用于拔尖学生培养计划2.0基地学校化学类专业低年级学生,是培养化学基础研究创新人才的高阶基础入门实验课程。本课程可以激发学生化学实验的兴趣,具备继续从事化学后续课程学习和化学研究的基本实验素养。通过以合成和测量为载体的单元实验或小综合实验,服务于基础单元操作学习、基础技能训练,或成为合成化学实验和化学测量学实验等课程学习必要的先导内容,为后续实验课程学习打基础。

Tailoring NH_(4)^(+)storage by regulating oxygen defect in ammonium vanadate

Defect engineering is an effective strategy for modifying the energy storage materials to improve their electrochemical performance.However,the impact of oxygen defect and its content on the electrochemical performances in the burgeoning aqueous NH_(4)^(+)storage field remains explored.Therefore,for the first time in this work,an oxygen-defective ammonium vanadate[(NH_(4))_(2)V_(10)O_(25)·8H_(2)O,denoted as Od-NHVO]with a novel 3D porous flower-like architecture was achieved via the reduction of thiourea in a mild reaction condition,which is a facile method that can realize the intention to regulate the oxygen defect content,with the capability of mass-production.The as-prepared Od_M-NHVO with moderate oxygen defect content can deliver a stable specific capacitance output(505 F g^(-1),252 mAh g^(-1)at 0.5 A g^(-1)with~80% capacitance retention after 10,000 cycles),which benefits from extra active sites,unimpeded NH_(4)^(+)-migration path and relatively high structure integrity.In contrast,low oxygen defect content will lead to the torpid electrochemical reaction kinetics while too high content of it will reduce the chargestorage capability and induce structural disintegration.The superior NH_(4)^(+)-storage behavior is achieved with the reversible intercalation/deintercalation process of NH_(4)^(+)accompanied by forming/breaking of hydrogen bond.As expected,the assembled flexible OdM-NHVO//PTCDI quasi-solid-state hybrid supercapacitor(FQSS HSC)also exhibits high areal capacitance,energy density and reliable flexibility.This work provides a new avenue for developing materials with oxygen-deficient structure for application in various aqueous non-metal cation storage systems.

中英高校无机化学课程比较研究

对7所英国罗素大学集团高校本科阶段无机课程的课程设置、教学内容、考核方式等进行了调研和分析,通过比较两国无机化学课程特点和教法的异同,为我国高校无机化学课程教学改革提供一些参考。

In situ confined vertical growth of Co_(2.5)Ni_(0.5)Si_(2)O_(5)(OH)_(4)nanoarrays on rGO for an efficient oxygen evolution reaction

Rational design of oxygen evolution reaction(OER)catalysts at low cost would greatly benefit the economy.Taking advantage of earth-abundant elements Si,Co and Ni,we produce a unique-structure where cobalt-nickel silicate hydroxide[Co_(2.5)Ni_(0.5)Si_(2)O_(5)(OH)_(4)]is vertically grown on a reduced graphene oxide(rGO)support(CNS@rGO).This is developed as a low-cost and prospective OER catalyst.Compared to cobalt or nickel silicate hydroxide@rGO(CS@rGO and NS@rGO,respectively)nanoarrays,the bimetal CNS@rGO nanoarray exhibits impressive OER performance with an overpotential of 307 mV@10 mA cm^(-2).This value is higher than that of CS@rGO and NS@rGO.The CNS@rGO nanoarray has an overpotential of 446 mV@100 mA cm^(-2),about 1.4 times that of the commercial RuO_(2)electrocatalyst.The achieved OER activity is superior to the state-of-the-art metal oxides/hydroxides and their derivatives.The vertically grown nanostructure and optimized metal-support electronic interactions play an indispensable role for OER performance improvement,including a fast electron transfer pathway,short proton/electron diffusion distance,more active metal centers,as well as optimized dualatomic electron density.Taking advantage of interlay chemical regulation and the in-situ growth method,the advanced-structural CNS@rGO nanoarrays provide a new horizon to the rational and flexible design of efficient and promising OER electrocatalysts.

创一流:应用化学专业建设的改革与实践

大连理工大学应用化学专业经历30多年的发展与建设,已经形成了鲜明的专业特色和优势。本文全面介绍了专业在人才培养模式、改革课程教学体系、提升专业教学条件、加强师资队伍建设、完善教育管理机制等方面的举措和实施成效。

Effective adsorptive denitrogenation from model fuels over yttrium ion-exchanged Y zeolite

The adsorption removal of indole and quinoline in octane with and without toluene over zeolites NaY and Yttrium Ion-exchanged Y(YY)using batch adsorption experiments was studied at 25℃and 0.1 MPa.YY was prepared by treating NaY with Y(NO3)3 solution twice via liquid ion-exchange method.NaY and YY were both characterized by XRD,SEM,N2 adsorption,XRF,NH3-TPD,and pyridine-FTIR techniques.Adsorption isotherms of indole,quinoline and toluene in octane were conducted at 25.0℃to explain the influence of toluene on nitrogen removal over NaY and YY.The partial destruct of the crystalline structure of NaY was observed after the introduction of yttrium ion,which led to an evident decline in BET surface area and pore volume of YY.Strong Br?nsted acidity and medium Lewis acidity were introduced by yttrium ion-exchange.Though the specific surface area and pore volume of YY were much lower than those of NaY,YY exhibited equivalent adsorption capacities for indole and quinoline as NaY in model fuels without toluene.In the presence of 20 vol%toluene,however,YY exhibited much higher adsorption capacities for indole and quinoline than NaY,especially in the case of quinoline.The improved toluene-tolerant of YY was ascribed to the strong acid–base interaction between YY and quinoline and the decreased adsorption strength between YY and toluene.

High adsorption of Cd(Ⅱ)by modification of synthetic zeolites Y,A and mordenite with thiourea

Zeolites Y,A and mordenite(ZY,ZA and ZM)were obtained from diatomite in a template-free system,and the products were modified by thiourea(TU).Characterization studies results indicated that the TU molecules were loaded onto the exterior surfaces of the synthetic zeolites as well as the channels.Elemental analysis and energy-dispersive X-ray spectrometer proved that the TU molecules loaded on to ZA were more than ZY and ZM.Removal of Cd(Ⅱ)was investigated,and itwas found that themodified zeolites have higher removal capacity,modified ZA is especially noticeable.In the adsorption experiments,the effects of various parameters such as sorbent content,contact time,concentration of cadmium solution,pH,selectivity and regeneration were discussed.At the best removal efficiency by modified zeolites,the maximum adsorption capacity is 94.3 mg·g^−1,103.2 mg·g^−1 and 89.7 mg·g^−1 at 25℃,respectively.The sorbents show good efficiency for the removal of Cd(Ⅱ)in the presence of different multivalent cations and have good regeneration effect.For the modified samples,removal experiments take place via ion exchange and complexation processes.

Mechanism of Macroalloying-induced Ductility in Ni_3Al

The bonding characteristics of Ni3Al doped with ternary elements has been investigated by means of the discrete variational Xα (DV-Xα) cluster method. From the computations. the addition of ternary element M (M= Pd. Ag. Cu and Co) substituting for the Ni sttes leads to the increase of delocalized bonding electrons. and the mechanism of ductilization of Ni3Al bV doping with M is explained based on the analysis of bonding characteristics. The increase of delocalized bonding electrons lowers the covalent bond directionality and strengthens grain boundary. The difference of strength between M-Al bond and M-Ni bond is an important factor in the effect of alloy stoichiometry on ductility. The larger the difference. the more the sensitivity to the alloy stoichiometry

Weak base favoring the synthesis of highly ordered V-MCM-41 with well-dispersed vanadium and the catalytic performances on selective oxidation of benzyl alcohol

The key to improve the performance of heteroatom catalysts is to ensure the orderliness of catalysts and the good dispersion of heteroatoms.The alkalinity plays the indispensable role in synthetic process of V-MCM-41 catalyst.The excessive alkalinity of synthetic system will make the MCM-41 difficult to crystallize,even to dissolve.It is easy to accumulate for heteroatomic species in the system of low alkalinity.Herein,the highly ordered VMCM-41 with high vanadic content in framework is synthesized in the condition of excessive NH3·H2 O in this paper.A series of characterization results prove the good dispersion of vanadium species,and most of vanadium gets into the framework of MCM-41 with the states of tetravalence and pentavalence.Furthermore,the modified MCM-41 by other transition metals is successful synthesized by the method of V-MCM-41 in this paper.The VMCM-41 shows well catalytic activity for the selective oxidation of benzyl alcohol,which up to 74.83%for the conversion of benzyl alcohol and 96.20%for selectivity of benzaldehyde when initial V/Si=0.10.The paper provides the possibility for industrial application of V-MCM-41 in the oxidation of benzyl alcohol for benzaldehyde.Besides,the work provides a significant idea for the synthesis of modified MCM-41 by well-dispersed transition metals.

Quench-tailored Al-doped V_(2)O_(5) nanomaterials for efficient aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries(ZIBs)are regarded as a promising competition to lithium-ion batteries as energy storage devices,owing to their high safety and low cost.However,the development of high-performance ZIBs is largely hindered by the shortage of ideal cathode materials with high-rate capability and long-cycle stability.Herein,we address this bottleneck issue by the quenching-tailored surface chemistry of V_(2)O_(5) cathode nanomaterial.By rapid quenching from high temperatures,Al ions are doped into V_(2)O_(5) lattice(Al-V_(2)O_(5))and abundant oxygen vacancies are formed on the surface/nearsurface,which facilitate the desired rapid electron transfers.Our density functional theory(DFT)simulations elucidate that the doping of Al ions into V_(2)O_(5) remarkably reduces the Zn^(2+)-diffusion barriers and improves the electrical conductivity of V_(2)O_(5).As a proof-of-concept application,the thus-optimized AlV_(2)O_(5) cathode delivers a superior specific capacity of 532 m Ah g^(-1) at 0.1 A g^(-1) and a long-cycling life with76%capacity retention after 5000 cycles,as well as a good rate performance.This work provides not only a novel strategy for tuning the surface chemistry of V_(2)O_(5) to boost the Zn^(2+)storage but also a general pathway of modifying metal oxides with improved electrochemical performance.

Adjusting oxygen vacancy of VO_(2)·xH_(2)O nanoarray architectures for efficient NH_(4)^(+) storage

Aqueous rechargeable batteries are the promising energy storge technology due to their safety,low cost,and environmental friendliness.Ammonium ion(NH_(4)^(+))is an ideal charge carrier for such batteries because of its small hydration radius and low molar mass.In this study,VO_(2)·xH_(2)O with rich oxygen defects(d-HVO)is designed and synthesized,and it exhibits unique nanoarray structure and good electrochemical performances for NH_(4)^(+)storge.Experimental and calculation results indicate that oxygen defects in d-HVO can enhance the conductivity and diffusion rate of NH_(4)^(+),leading to improved electrochemical performances.The most significant improvement is observed in d-HVO with 2 mmol thiourea(d-HVO-2)(220 mAh·g^(-1) at 0.1 A·g^(-1)),which has a moderate defect content.A full cell is assembled using d-HVO-2 as the anode and polyaniline(PANI)as the cathode,which shows excellent cycling stability with a capacity retention rate of 80%after 1000 cycles and outstanding power density up to 4540 W·kg^(-1).Moreover,the flexible d-HVO-2||PANI battery,based on quasi-solid electrolyte,shows excellent flexibility under different bending conditions.This study provides a new approach for designing and developing high-performance NH_(4)^(+)storage electrode materials.

Intermetallic ferric nickel silicide alloy derived from magadiite by magnesiothermic reaction as bifunctional electrocatalyst for overall water splitting

As the cleanest energy source,hydrogen energy is regarded as the most promising fuel.Water electrolysis,as the primary means of hydrogen production,has constantly been the focus of attention in the energy conversion field.Developing eco-friendly,cheap,safe and efficient catalysts for electrochemical water splitting(EWS)is the key challenge.Herein,the intermetallic silicide alloy is first synthesized via a facile magnesiothermic reduction and employed as bifunctional electrocatalysts for EWS.Ferric-nickel silicide(denoted as FeNiSi)alloy is designed and shows a good electrocatalytic performance for EWS.The lattice distortions of FeNiSi enhance the electrocatalytic activity.Besides,the porous structure affords more active sites and improves the reaction kinetics.As a consequence,FeNiSi delivers an excellent performance with overpotential of 308 mV for oxygen evolution reaction(OER)and 386 mV for hydrogen evolution reaction(HER)at 10 mA·cm−2 in 1 M KOH.The stability structure of intermetallic silicide achieves an outstanding durability with an unchanged potential of 1.66 V for overall water splitting at 10 mA·cm−2 for 15 h.This work not only provides a facile method for the synthesis of intermetallic silicide with considerable porous structures,but also develops the potential of intermetallic silicide alloy as bifunctional electrocatalysts for EWS,which opens up a new avenue for the design and application of intermetallic silicide alloy.

Synergistic effect of K^(+)and PANI in vanadium oxide hydration by interlayer engineering boosts the ammonium ion storage

Aqueous ammonium-ion(NH_(4)^(+))hybrid supercapacitor(AA-HSC),as a new type of energy storage device with great potential,is in the initial stage of rapid development.Based on its special energy storage mechanism,exploiting novel NH_(4)^(+)-hostingmaterials is still a great challenge.Herein,vanadium oxide hydration(VOH)tuned by interlayer engineering of K+/PANI co-intercalation,named KVO/PANI,is designed for AA-HSC.Intercalated PANI can shield interaction between NH_(4)^(+)and V–O layers to some extent and enlarge interlayer space,which improves the efficiency of reversible NH_(4)^(+)(de)insertion.However,K+enhances redox activity and electronic conductivity.The synergistic effect of co-intercalation optimizes intercalation pseudocapacitive behavior during the(de)ammonization process,which is reported in NH_(4)^(+)storage for the first time.Theoretical calculations reveal that the lowered electron transport barrier and enhanced electronic conductivity improveNH_(4)^(+)kinetics and exhibit high capacitance for charge storage.The KVO/PANI can deliver the specific capacitance of 340 F g^(−1) at 0.5 A g^(−1) and retain 177 F g^(−1) at 10 A g^(−1).Pairing with activated carbon,the AA-HSC can achieve a decent energy density of 31.8 Wh kg^(−1).This work gives inorganic/organic co-intercalation that can enhance the NH_(4)^(+)storage of VOH by interlayer engineering.The strategy can be used to design other materials for aqueous energy storage systems.

Structural regulation of vanadium oxide by poly(3,4-ethylenedioxithiophene)intercalation for ammonium-ion supercapacitors

Recently,ammonium-ion(NH_(4)^(+))storage is in a booming stage in aqueous energy storage systems due to its multitudinous merits.To seek suitable electrode materials with excellent NH_(4)^(+)-storage is still in the exploratory stage and full of challenge.Herein,an inorganic-polymer hybrid,poly(3,4-ethylenedioxithiophene)(PEDOT)intercalated hydrated vanadium oxide(VOH),named as VOH/PEDOT,is developed to tune the structure of VOH for boosting NH_(4)^(+)storage.By the intercalation of PEDOT,the interlayer space of VOH is increased from 11.5Åto 14.2Å,which notably facilitates the rapid transport of electrons and charges between layers and improves the electrochemical properties for NH_(4)^(+)storage.The achieved performances are much better than progressive NH_(4)^(+)hosting materials.In addition,the concentration of polyvinyl alcohol/ammonium chloride(PVA/NH_(4)Cl)electrolyte exerts a great impact on the NH_(4)^(+)storage in VOH/PEDOT.The VOH/PEDOT electrode delivers specific capacitance of 327 F g^(-1)in 1 M PVA/NH_(4)Cl electrolyte at-0.2–1 V.Furthermore,the quasi-solid-state VOH/PEDOT//active carbon hybrid supercapacitor(QSS VOH/PEDOT//AC HSC)device is assembled for NH_(4)^(+)storage,and it exhibits the capacitance of 328 mF cm^(-2)at 1 mA cm^(-2).The energy density of QSS VOH/PEDOT//AC NH4 t-HSC can reach 2.9 Wh m^(-2)(2.6 mWh cm^(-3),10.4 Wh kg^(-1))at 1 Wm^(-2)(0.9 mWh cm-3,35.7 W kg^(-1)).This work not only proves that the PEDOT intercalation can boost the NH_(4)^(+)storage capacity of vanadium oxides,but also provides a novel direction for the development of NH_(4)^(+)storage materials.

Construction interlayer structure of hydrated vanadium oxides with tunable P-band center of oxygen towards enhanced aqueous Zn-ion batteries

Layered materials with adjustable framework,as the most potential cathode materials for aqueous rechargeable zinc ion batterie,have high capacity,permit of rapid ion diffusion,and charge transfer channels.Previous studies have widely investigated their preparation and storage mechanism,but the intrinsic relationship between the structural design of layered cathode materials and electrochemical performance has not been well established.In this work,based on the first principles calculations and experiments,a crucial strategy of pre-intercalated metalions in vanadium oxide interlayer with administrable p-band center(ε_(p))of O is explored to enhance Zn^(2+)storage.This regulation of the degree of covalent bond and the average charge of O atoms varies the binding energy between Zn^(2+)and O,thus affecting the intercalation/de-intercalation of Zn2þ.The present study demonstrates thatεp of O can be used as an important indicator to boost Zn2þstorage,which provides a new concept toward the controlled design and application of layered materials.

Single‑Atom Catalysts:Advances and Challenges in Metal‑Support Interactions for Enhanced Electrocatalysis

Single-atom catalysts(SACs),which contain a single metal atom supported on a well-confined substrate,are among the most promising heterogeneous catalysts owing to their unique advantages,such as high intrinsic activity and selectivity,tunable bonds and coordination,abundant metal-containing active sites,and atomic economy.Since metal-support interactions(MSIs)in SACs exert a substantial influence on the catalytic properties,gaining a profound understanding and recognition of catalytic reactions depends greatly on investigating MSIs both experimentally and computationally.Hence,the engineer-ing and modulation of MSIs are regarded as one of the most efficient methods to rationally design SACs with disruptively enhanced catalytic properties.In this review,we track the recent advances in SACs from an MSI perspective.We then discuss the existing MSIs in SACs and elucidate the significant role of strong MSIs in catalytic properties and mechanisms.The chal-lenges hindering the rational design of supported SACs with strong MSIs,which are currently still far from being completely understood and overcome,are described.In addition,the correlation between strong MSIs and electrocatalytic activities in SACs,including an outlook to increase our understanding of MSIs,is discussed.Finally,the present review provides some perspectives and an in-depth understanding of strong MSIs to advance high-performing SACs.

PVA-assisted hydrated vanadium pentoxide/reduced graphene oxide films for excellent Li^(+)and Zn^(2+)storage properties

Low-cost,high safety and environment-friendly aqueous energy storage systems(ESSs)are huge potential for grid-level energy storage,but the(de)intercalation of metal ions in the electrode materials(e.g.vanadium oxides)to obtain superior long-term cycling stability is a significant challenge.Herein,we demonstrate that polyvinyl alcohol(PVA)-assisted hydrated vanadium pentoxide/reduced graphene oxide(V_(2)O_(5)·n H_(2)O/r GO/PVA,denoted as the VGP)films enable long cycle stability and high capacity for the Li^(+)and Zn^(2+)storages in both the VGP//Li Cl(aq)//VGP and the VGP//Zn SO4(aq)//Zn cells.The binderfree VGP films are synthesized by a one-step hydrothermal method combination with the filtration.The extensive hydrogen bonds are formed among PVA,GO and H_(2)O,and they act as structural pillars and connect the adjacent layers as glue,which contributes to the ultrahigh specific capacitance and ultralong cyclic performance of Li^(+)and Zn^(2+)storage properties.As for Li^(+)storage,the binder-free VGP4 film(4mg PVA)electrode achieves the highest specific capacitance up to 1381 F g^(-1)at 1.0 A g^(-1)in the three-electrode system and 962 F g^(-1)at 1.0 A g^(-1)in the symmetric two-electrode system.It also behaves the outstanding cyclic performance with the capacitance retention of 96.5%after 15000 cycles in the three-electrode system and 99.7%after 25000 cycles in the symmetric two-electrode system.As for Zn^(2+)storage,the binder-free VGP4 film electrode exhibits the high specific capacity of 184 m A h g^(-1)at 0.5A g^(-1)in the VGP4//Zn SO4(aq)//Zn cell and the superb cycle performance of 98.5%after 25000 cycles.This work not only provides a new strategy for the construction of vanadium oxides composites and demonstrates the potential application of PVA-assisted binder-free film with excellent electrochemical properties,but also extends to construct other potential electrode materials for metal ion storage cells.

Energy paths of twin-related lattice reorientation in hexagonal metals via ab initio calculations

Employing ab initio calculations, we systematically investigated tile energy paths of [1012] twin-related lattice reorientation in hexagonal metals Be, Mg, Sc, Ti, Co, Y, Zr, Tc, Ru, Gd, Tb, Dy, Ho, Er, Tin, Lu, Hf, Re, and Os. Among the studied systems, lattice reorientation energy increases in the order of Mg, Gd, Tb, Dy, Zr, Tc, Ti, Ho, Y, Co, Er, Sc, Be, Tin, Lu, Hf, Re, Ru and Os. The reorientation process consists of shear and shuffle components. Concerning the significance of shuffle, these hexagonal metals fall into two groups. In the first group, which includes Mg, Co, Ru, Re and Os, regardless of the shear amount, subsequent shuffle is an energy-uphill process, while in the second group, which includes Ti, Tc, Be, Y. Gd, Tb, Dy, Ho, Zr, Er, Sc, Hf, Lu and Tin, shuffle becomes an energy-downhill process if shear component reaches an adequate level （at least 60%）. These results qualitatively explain the present observation of lattice reorientation in hexagonal metals, and shed light upon a general understanding on the [1012] twinning behavior in the aim of improving materials properties.

Preparation of lithium ion-sieve and utilizing in recovery of lithium from seawater

Lithium is one of the most important light metals,which is widely used as raw materials for large-capacity rechargeable batteries,light aircraft alloys and nuclear fusion fuel.Seawater,which contains 250 billion tons of lithium in total,has thus recently been noticed as a possible resource of lithium.While,since the aver-age concentration of lithium in seawater is quite low(0.17 mg$L–1),enriching it to an adequate high density becomes the primary step for industrial applications.The adsorption method is the most prospective technology for increasing the concentration of lithium in liquid.Among the adsorbents for lithium,the ion-sieve is a kind of special absorbent which has high selectivity for Li+,especially the spinel manganese oxides(SMO),which among the series of ion-sieves,has become the most promising adsorption material for lithium.In this study,the SMO ion-sieve was prepared by a coprecipitation method.The preparation conditions were discussed and the sample characters were analyzed.Recovery of Li+from seawater were studied in batch experiments using prepared ion-sieve,and the effect of solution pH and the uptake rates were also investigated in different Li+solutions.