Dear Editor,This letter presents some control strategies for quadrotor unmanned aerial vehicle(UAV)leader-follower formation model,where the stochastic impulsive deception attacks are fully considered.Based on Lyapuno...Dear Editor,This letter presents some control strategies for quadrotor unmanned aerial vehicle(UAV)leader-follower formation model,where the stochastic impulsive deception attacks are fully considered.Based on Lyapunov method,the outer loop and the inner loop controllers of quadrotor UAV are designed,respectively.Moreover,a relationship between continuous control laws,stochastic impulsive sequences,and impulsive intensity is established in this letter.展开更多
The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations ...The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.展开更多
In this work,Mn-doped MoS_(2)hierarchical nanotubes have been prepared by a solvothermal method.The diameter of Mn-MoS_(2)nanotubes is about 100–_(2)00 nm and the wall thickness is about 10–_(2)0 nm.Hierarchical ult...In this work,Mn-doped MoS_(2)hierarchical nanotubes have been prepared by a solvothermal method.The diameter of Mn-MoS_(2)nanotubes is about 100–_(2)00 nm and the wall thickness is about 10–_(2)0 nm.Hierarchical ultrathin sheets are formed on the surface of MoS_(2)nanotubes.展开更多
In this study,Ni_(x)Fe_(y)O_(4)-BiOBr(NFB)composites with different etching degrees were successfully synthesized via a simple hydrothermal method.The etching degree was regulated by adjusting the pH during the synthe...In this study,Ni_(x)Fe_(y)O_(4)-BiOBr(NFB)composites with different etching degrees were successfully synthesized via a simple hydrothermal method.The etching degree was regulated by adjusting the pH during the synthesis process.The superiorities of the obtained materials can be outlined as follows:(i)BiOBr has the property of generating H_(2)O_(2)in situ;and(ii)Ni_(x)Fe_(y)O_(4)nanoparticles in the composite could effectively promote the decomposition of H_(2)O_(2),which proceeded via the two-electron reduction of O_(2)on the surface of BiOBr.The excellent properties of the prepared materials were confirmed through the photocatalytic degradation of bisphenol A under visible light irradiation,which is denoted as a solid-liquid-interfacial Fenton system.This work may pave the way for in situ H_(2)O_(2)generation and decomposition;thus,the defects of traditional Fenton reaction systems,such as strict reaction conditions,high costs and secondary contamination after reactions,can be intelligently overcome.展开更多
In the present investigation,we examined the water and oxygen reduction ability of ZnCr-layered double hydroxide decorated with Au nanoparticles and reduced graphene oxide,prepared via in situ crystallization and phot...In the present investigation,we examined the water and oxygen reduction ability of ZnCr-layered double hydroxide decorated with Au nanoparticles and reduced graphene oxide,prepared via in situ crystallization and photoreduction method.The fabricated Au@LDH/RGO composite was well characterized by different analytical instruments like PXRD,FTIR,Raman,XPS,EDX,FESEM,and TEM,suggesting strong interaction between the components of the ternary hybrid.Further,the Au@LDH/RGO catalyst shows the best hydrogen evolution reaction(HER),i.e.,918.76μmol/2 h(no.evolved H_(2)gas is 4.9903×10^(15)cm^(−2)s^(−1))with an ACE of 10.5%and excellent reusability up to 8 h with little change in activity.Additionally,the ternary nanohybrid depicts robust photocatalytic O_(2)reduction reaction performance,i.e.,24.3μmol/2 h of H_(2)O_(2)(SCC=0.23%),which goes via a superoxide radical mechanism as confirmed through tracing experiments.The observed high photocatalytic activity is attributed to the synergetic effect of both plasmonic Au nanoparticles and conjugatedΠ-skeleton of RGO,which resulted in high charge carrier density and reduction of the recombination process.This observation is well justified by Mott-Schottky,EIS,PL,and photocurrent measurements.Further,the HER performance was also tested under different hole scavengers to figure out their effect.The SPR effect of Au and conjugated cyclic carbon network of RGO plays a pivotal part in improving the H_(2)and H_(2)O_(2)generation ability of LDH under visible light illumination.展开更多
Developing highly efficient,Earth-abundant,and long-term stable electrocatalysts for the oxygen evolution reaction (OER) is of great importance for realizing industrial hydrogen generation from water splitting.Herein,...Developing highly efficient,Earth-abundant,and long-term stable electrocatalysts for the oxygen evolution reaction (OER) is of great importance for realizing industrial hydrogen generation from water splitting.Herein,a series of novel Fe and Nb co-doped β-Ni(OH)_(2)nanosheet arrays were successfully grown in situ on Ni foam via a chlorine etching method.The representative NiFe_(3)Nb_(2)-OH displayed outstanding OER performance with an overpotential of 294 mV to deliver 100 mA cm^(-2) in an alkaline electrolyte,outperforming other Ni related electrocatalysts.NiFe_(3)Nb_(2)-OH exhibited a stability of 90 h without obvious potential change at 50 mA cm^(-2).Significantly,the doped Fe and Nb effectively enhanced the electrochemical active area and electronic transfer capability of β-Ni(OH)_(2).Density functional theory (DFT) calculations indicated that the Gibbs free energy of the OER intermediates on the Fe,Nb co-doped β-Ni(OH)_(2)electrode was optimized.The tuned electronic interactions between Fe,Nb and Ni apparently boosted the OER performance of NiFe_(3)Nb_(2)-OH.These results demonstrated that Fe and Nb co-doped β-Ni(OH)_(2)is a highly efficient OER electrocatalyst in alkaline media.展开更多
Electrocatalytic CO_(2) reduction reactions(CO_(2)RRs),an efficient method of converting carbon dioxide into valuable fuels and chemicals,are attractive as well as challenging.In this work,Cu_(2)O nanostructures with ...Electrocatalytic CO_(2) reduction reactions(CO_(2)RRs),an efficient method of converting carbon dioxide into valuable fuels and chemicals,are attractive as well as challenging.In this work,Cu_(2)O nanostructures with active facets(face-raised cubic structures(F-Cu_(2)O)with the(100)facet,octahedral structures(O-Cu_(2)O)with the(111)facet and edge-and corner-truncated octahedral structures(T-Cu_(2)O)with both the(100)and(111)facets)were synthesized by a wet chemical reduction method.The surface of Cu_(2)O nanostructures was reconstructed in situ to form Cu_(2)O/Cu with a highly active interface during the conversion of CO_(2) into C_(2)H_(4),which is named F-Cu_(2)O/Cu,O-Cu_(2)O/Cu and T-Cu_(2)O/Cu.The C_(2)H_(4) selectivity on Cu_(2)O/Cu catalysts follows the order of O-Cu_(2)O/Cu<F-Cu_(2)O/Cu<T-Cu_(2)O/Cu,and the faradaic efficiencies of C_(2)H_(4) are 11.2%,24.9%,and 58.0% at -1.1 V versus the reversible hydrogen electrode,respectively.The experimental results combined with operando surface-enhanced Raman spectroscopy reveal that the Cu_(2)O/Cu interface enhances *CO adsorption and decreases the activation energy of C-C coupling,which is also supported by density functional theory(DFT)calculations.This study will pave a feasible pathway for electrochemical energy storage and convention by crystal facet engineering and interface engineering.展开更多
A new mixed alkali hydro-isocyanurate,RbNa(HC_(3)N_(3)O_(3))·2H_(2)O,with the noncentrosymmetric space group Pna21(No.33),has been successfully grown by a hydrothermal method.The structure can be described as 2D ...A new mixed alkali hydro-isocyanurate,RbNa(HC_(3)N_(3)O_(3))·2H_(2)O,with the noncentrosymmetric space group Pna21(No.33),has been successfully grown by a hydrothermal method.The structure can be described as 2D wavy[Na(HC_(3)N_(3)O_(3))O_(4)]∞layers separated by Rb atoms.The UV-vis diffuse reflection measurement revealed that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O has a large band gap of 5.10 eV,corresponding to the UV cutoff edge of 241 nm.The polarizing microscope measurement of a micron-sized single crystal shows that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O has a large birefringence of 0.194.The powder SHG measurement indicated that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O exhibits a strong SHG effect that is 5.3 times that of KH_(2)PO_(4)(KDP)and can realize phase-matching in the visible and UV region.Moreover,the differences in the SHG responses between RbNa(HC_(3)N_(3)O_(3))·2H_(2)O and two isostructural compounds have been investigated,which depend heavily on the structural modulation of the(HC_(3)N_(3)O_(3))2-group by cations.Meanwhile,the electronic structures and optical properties were well analyzed using DFT methods.展开更多
TiO_(2)(B)nanotubes(NTs)were used as carriers to support metal Cu/Ni nanoparticles for the catalytic hydrolysis of ammonia borane(NH_(3)BH_(3),AB)under visible light.The TiO_(2)NTs were first prepared by the hydrother...TiO_(2)(B)nanotubes(NTs)were used as carriers to support metal Cu/Ni nanoparticles for the catalytic hydrolysis of ammonia borane(NH_(3)BH_(3),AB)under visible light.The TiO_(2)NTs were first prepared by the hydrothermal method and subsequently loaded with Cu/Ni metal nanoparticles by the impregnation reduction method.The structure,morphology,and chemical composition of the as-obtained catalysts were characterized by X-ray diffraction(XRD),scanning electron microscopy coupled with energy dispersive X-ray spectroscopy(SEM-EDX),transmission electron microscopy(TEM),inductively coupled plasma emission spectroscopy(ICP),and ultraviolet-visible spectroscopy(UV-Vis).The characterization results revealed that the metal nanoparticles were uniformly loaded on the surface of the TiO_(2)NTs,while the band gap of the catalyst was reduced significantly from 3.22 to 2.68 eV.The catalysts showed an excellent photocatalytic performance towards the hydrolysis of AB for H_(2)production.Thus,the H_(2)production rate of Cu_(0.64)Ni_(0.36)-TiO_(2)NTs reached 5763.86 mL g^(-1)min^(-1),with a total turnover frequency(TOF)of 15.90 mol H_(2)(mol cat)^(-1)min^(-1)for a loading volume of metal particles of 5.25 wt%.The results presented herein demonstrate that TiO_(2)(B)can be a potential photocatalyst for effective H_(2)production,and also provide a cheap and effective approach to improve the light-to-H_(2)energy conversion.展开更多
A new deep-ultraviolet nonlinear optical crystal,Cs_(12)Zn_(4)(B_(5)O_(10))_(4),was synthesized via a high temperature solution method.The crystal structure was solved in the noncentrosymmetric space group(Cc,no.9).Ow...A new deep-ultraviolet nonlinear optical crystal,Cs_(12)Zn_(4)(B_(5)O_(10))_(4),was synthesized via a high temperature solution method.The crystal structure was solved in the noncentrosymmetric space group(Cc,no.9).Owing to the cation size effect,from X_(3)ZnB_(5)O_(10)(X=Na,K,and Rb)to Cs_(12)Zn_(4)(B_(5)O_(10))_(4),the structure changes from centrosymmetric to noncentrosymmetric.Cs_(12)Zn_(4)(B_(5)O_(10))_(4) exhibits a 3D[ZnB_(5)O_(10)]_(∞) network,however,X_(3)ZnB_(5)O_(10)(X=Na,K,and Rb)exhibits a 2D[ZnB_(5)O_(10)]_(∞)layer.It is worth mentioning that Cs_(12)Zn_(4)(B_(5)O_(10))_(4) displays a short cutoff edge(below 185 nm),which is remarkable among the reported Zn-containing NLO crystals.Meanwhile,the compound exhibits a moderate SHG response and melts congruently.In addition,the relationship between its structure and NLO properties was also discussed in detail using the density functional theory(DFT)method.展开更多
Herein,we report the synthesis of hybrid nanostructures obtained by densely growing MoS_(2)nanosheet layers on hydrophobic hollow carbon spheres(abbreviated as MoS_(2)-HCS)through a solvothermal method.The morphologie...Herein,we report the synthesis of hybrid nanostructures obtained by densely growing MoS_(2)nanosheet layers on hydrophobic hollow carbon spheres(abbreviated as MoS_(2)-HCS)through a solvothermal method.The morphologies and compositions of the MoS_(2)-HCS hybrid are well investigated.The electrochemical performance of the MoS_(2)-HCS sphere is investigated in both supercapacitors and the hydrogen evolution reaction.展开更多
In the quest for amplifying the inherent capabilities of noble metals,crafting precise metal–support interfacial bonds stands as a challenging yet fruitful endeavor.Here,we introduce an approach to synthesize excepti...In the quest for amplifying the inherent capabilities of noble metals,crafting precise metal–support interfacial bonds stands as a challenging yet fruitful endeavor.Here,we introduce an approach to synthesize exceptionally small metal nanoparticles(NPs),which are securely anchored onto cobalt-based metal–organic framework(Co-MOF)nanosheets through a wet chemical method.The creation of metal–oxygen linkages between these Ir NPs and Co-MOF not only guarantees structural robustness but also ensures a generous exposure of active sites.Importantly,the distinct interface fine-tunes the electronic configuration of the composites by facilitating charge transfer along the Ir–O–Co pathway,consequently boosting the reaction dynamics.As a result,the hydrogen evolution reaction(HER)performance of our pioneering product,Ir@Co-MOF,in alkaline media,rivals that of the benchmark Pt/C catalyst and surpasses other recent noble metal catalysts.Theoretical analysis reveals that the exceptional HER efficiency of Ir@Co-MOF originates from the optimal adsorption energies for water and hydrogen,a consequence of electron re-allocation owing to its unique interfacial bond.展开更多
The ever-increasing obligation of green and sustainable energy has intensified rigorous research on improving efficient electrochemical energy transition and storage systems.Herein,CoS_(2)prickly-pear-like sheet-inter...The ever-increasing obligation of green and sustainable energy has intensified rigorous research on improving efficient electrochemical energy transition and storage systems.Herein,CoS_(2)prickly-pear-like sheet-intermingled metal carbide(Mo_(2)C and W_(2)C)hybrids were synthesized using a facile hydrothermal method.The fabricated hierarchical CoS_(2)-W_(2)C and CoS_(2)-Mo_(2)C hybrid structures were explored for their pseudo-capacitive behaviour by half-cell studies with specific capacities of 720 and 380 C g^(−1)at 2 A g^(−1),respectively,with great cycling stability.The synthesized CoS_(2)-W_(2)C and CoS_(2)-Mo_(2)C hybrid asymmetric supercapacitors demonstrated an elevated specific capacitance,reaching 423 F g^(−1)at a current density of 2 A g^(−1)within an extended voltage range of 1.6 V.Additionally,the highest energy density of 150 W h kg^(−1)was achieved at a maximum power density of 4.5 kW kg^(−1)along with a superior capacitance retention of 94.1%after 5000 cycles.As hydrogen evolution catalysts,the CoS_(2)-W_(2)C hybrid required small overpotentials of 50 and 42 mV,whereas the CoS_(2)-Mo_(2)C hybrid required 54 and 50 mV to deliver 10 mA cm^(−2)current density in acid and KOH solution,respectively.This study related to metal carbide-interconnected metal sulfide provides a promising opportunity for the fabrication/design and application of multifunctional electrocatalysts.展开更多
Developing low-cost and efficient catalysts for hydrogen evolution is of great significance to solve the human energy crisis.In this work,ruthenium-nickel alloy is synthesized by a solvothermal method.The ruthenium-ni...Developing low-cost and efficient catalysts for hydrogen evolution is of great significance to solve the human energy crisis.In this work,ruthenium-nickel alloy is synthesized by a solvothermal method.The ruthenium-nickel alloy shows distinguished catalytic performance and durability for the hydrogen evolution reaction in alkaline solution(1 M KOH).Only 21,76,222 and 323 mV overpotentials are required to reach current densities of 10,100,1000 and 2000 mA cm^(-2).After 150 hours of a durability test at a current density of-400 mA cm^(-2),the alloy also shows outstanding durability.Density functional theory(DFT)further shows that ruthenium-nickel alloy composites can optimize the reaction barrier of alkaline hydrogen evolution.This study provides a valuable method for developing high-performance and lowprice alloy catalysts for hydrogen evolution.展开更多
Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits.Therefore,titanium-based materials have attracted great attention due to their high stability.Here,Na_(2)...Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits.Therefore,titanium-based materials have attracted great attention due to their high stability.Here,Na_(2)Li_(2)Ti_(6)O_(14)nanofibers as anode materials were prepared through a controlled electrospinning method.The Na_(2)Li_(2)Ti_(6)O_(14)nanofibers presented superior electrochemical performance with high rate capability and long cycle life and can be regarded as a competitive anode candidate for advanced Li-ion batteries.One-dimensional(1D)Na_(2)Li_(2)Ti_(6)O_(14)nanofibers are able to deliver a capacity of 128.5 mA h g^(-1)at 0.5C,and demonstrate superior high-rate charge-discharge capability and cycling stability(the reversible charge capacity is 77.8 mA h g^(-1)with a capacity retention of 99.45%at the rate of 10C after 800 cycles).The 1D structure is considered to contribute remarkably to increased rate capability and stability.This simple and scalable method indicates that the Na_(2)Li_(2)Ti_(6)O_(14)nanofibers have a practical application potential for high performance lithium-ion batteries.展开更多
A double network nested foam composite with tunable electromagnetic wave absorption performance was fabricated via a carbonization,impregnation,and chemical vapor infiltration method.The research results indicated tha...A double network nested foam composite with tunable electromagnetic wave absorption performance was fabricated via a carbonization,impregnation,and chemical vapor infiltration method.The research results indicated that the three-dimensional interconnected carbon foam was successfully enhanced by the SiC nanowire network.As expected,the electromagnetic absorption performance of the as-prepared SiC nanowire reinforced carbon foam(SiC_(nw)/CF)was greatly improved by the introduction of the SiC nanowires.The SiC_(nw)/CF composite prepared with a lower concentration of Ni catalyst possessed an excellent microwave absorption property with the lowest reflection loss value of-36.31 dB with a matched thickness of 2.60 mm accompanied by the widest effective bandwidth of 4.52 dB.An increase in catalyst concentration degraded the electromagnetic absorption ability to a certain extent.A potential microwave absorption schematic diagram was finally proposed,and it stated that the SiC nanowire network played an essential role in the improvement of the electromagnetic absorption properties.展开更多
Transition metal phosphides are considered ideal alternatives for noble metal catalysts in hydrogen evolution reactions.In this study,amorphous NiCuFeP nanosheets were uniformly coated on self-supporting Cu_(3)P nanow...Transition metal phosphides are considered ideal alternatives for noble metal catalysts in hydrogen evolution reactions.In this study,amorphous NiCuFeP nanosheets were uniformly coated on self-supporting Cu_(3)P nanowire arrays through a facile electrodeposition method.The obtained_(3)D hierarchical NiCuFeP@Cu_(3)P/CF with good conductivity and abundant active sites was used as a hydrogen evolution reaction electrocatalyst.There are strong electronic interactions between each component of the material,as well as between the metal elements and P,which are conducive to improving the catalytic performance.展开更多
An oxygen reduction reaction(ORR)catalyst is a crucial component of metal–air batteries.Herein,modified carbon nanotubes are used to support iron phthalocyanine,followed by the fabrication of single-atom and cluster ...An oxygen reduction reaction(ORR)catalyst is a crucial component of metal–air batteries.Herein,modified carbon nanotubes are used to support iron phthalocyanine,followed by the fabrication of single-atom and cluster coexisting catalysts by the fast microwave method.The two catalysts have Fe–N_(5)and Fe–P–N_(4)coordination structures,respectively.Electrochemical tests show that the FeNC/Fe–N_(5)–C and FeNC/Fe–P–N_(4)–C catalysts have half-wave potentials of 0.906 and 0.886 V in an alkaline solvent,respectively.The Zn–air battery prepared with the FeNC/Fe–N_(5)–C catalyst has a specific capacity of 791 mA h g^(−1)and a maximum power density of 190 mW cm^(−2).DFT calculations show that the axial coordination bonds in FeNC/Fe–N_(5)–C and FeNC/Fe–P–N_(4)–C are conducive to the acceleration of the transfer of electrons.The d-band centers of the axial coordination Fe–N_(5)and Fe–P–N_(4)are closer to the Fermi level,confirming that the presence of the axial coordination bonds enhances the adsorption of the reaction intermediates and reduces the ORR barriers.展开更多
The development of multiple metal-organic framework(MOF)thin films with high lattice mismatch is still a challenging task.Herein we report a series of single and multiple(bi-varietal and tri-varietal)pillarlayered MOF...The development of multiple metal-organic framework(MOF)thin films with high lattice mismatch is still a challenging task.Herein we report a series of single and multiple(bi-varietal and tri-varietal)pillarlayered MOF thin films(surface-coordinated MOF thin films,SURMOFs)[Cu_(2)L_(2)dabco]_(n)(L=bdc,bpc and tpdc)with preferred[001]-orientation on the substrate surfaces using a liquid-phase epitaxial(LPE)layer by layer pump method.The single SURMOFs with the same c-lattice parameters but different a-and b-lattice parameters result in the successful growth of oriented multiple SURMOFs with high lattice mismatch(up to 77.8%).The vapor adsorption results show that the representative bi-varietal SURMOF with large lattice mismatch has different adsorption behavior from single SURMOFs,providing a new strategy to achieve tuning of the adsorption kinetics performance in sensing applications.展开更多
The reasonable design of electrode materials with heterojunctions and vacancies is a promising strategy to elevate their electrochemical performances.Herein,tin-based sulfide composites with heterojunctions and sulfur...The reasonable design of electrode materials with heterojunctions and vacancies is a promising strategy to elevate their electrochemical performances.Herein,tin-based sulfide composites with heterojunctions and sulfur vacancies encapsulated by reduced graphene oxide(SnS_(2-x)P_(x)/RGO)were successfully designed and synthesized via a facile hydrothermal assisted phosphating method.The introduction of sulfur vacancies and construction of SnS-SnS2 heterojunctions were realized simultaneously by the phosphating process.The synergistic effect of the heterojunction,sulfur vacancy and phosphorus-doping could improve the conductivity,accelerate the ion transport dynamics,and enhance structural stability.Thus,high-rate,long-term cycling stability was observed for Li-half cells(337 mA h g^(-1) maintained after 3000 cycles at 10 A g^(-1))and Na-half cells(199 mA h g^(-1) maintained after 4000 cycles at 2 A g^(-1)).The design strategy can effectively improve the energy storage performance of tin based sulfides and can be extended to other metal sulfides.展开更多
基金supported by the National Natural Science Foundation of China(62173215)the Project for the Integrated Development of the City and Universities in Jinan(JNSX2024016)。
文摘Dear Editor,This letter presents some control strategies for quadrotor unmanned aerial vehicle(UAV)leader-follower formation model,where the stochastic impulsive deception attacks are fully considered.Based on Lyapunov method,the outer loop and the inner loop controllers of quadrotor UAV are designed,respectively.Moreover,a relationship between continuous control laws,stochastic impulsive sequences,and impulsive intensity is established in this letter.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604200)the National Natural Science Foundation of China(Grant No.12261131495)Institute of Systems Science,Beijing Wuzi University(Grant No.BWUISS21).
文摘The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.
基金supported by the NationalNatural Science Foundation of China(No.11774188)the Incubation Program of Universities'Preponderant Discipline of Shandong Province(No.03010304)+1 种基金Mountain Tai Young Scholarship(No.23170504)the Natural Science Foundation of Shandong Province(No.ZR2018QB003,JQ201802).
文摘In this work,Mn-doped MoS_(2)hierarchical nanotubes have been prepared by a solvothermal method.The diameter of Mn-MoS_(2)nanotubes is about 100–_(2)00 nm and the wall thickness is about 10–_(2)0 nm.Hierarchical ultrathin sheets are formed on the surface of MoS_(2)nanotubes.
基金financially supported by the National Natural Science Foundation of China(No.21777063,21507046,21476098,21407065)This study was supported by the high performance computing platform of Jiangsu University.
文摘In this study,Ni_(x)Fe_(y)O_(4)-BiOBr(NFB)composites with different etching degrees were successfully synthesized via a simple hydrothermal method.The etching degree was regulated by adjusting the pH during the synthesis process.The superiorities of the obtained materials can be outlined as follows:(i)BiOBr has the property of generating H_(2)O_(2)in situ;and(ii)Ni_(x)Fe_(y)O_(4)nanoparticles in the composite could effectively promote the decomposition of H_(2)O_(2),which proceeded via the two-electron reduction of O_(2)on the surface of BiOBr.The excellent properties of the prepared materials were confirmed through the photocatalytic degradation of bisphenol A under visible light irradiation,which is denoted as a solid-liquid-interfacial Fenton system.This work may pave the way for in situ H_(2)O_(2)generation and decomposition;thus,the defects of traditional Fenton reaction systems,such as strict reaction conditions,high costs and secondary contamination after reactions,can be intelligently overcome.
文摘In the present investigation,we examined the water and oxygen reduction ability of ZnCr-layered double hydroxide decorated with Au nanoparticles and reduced graphene oxide,prepared via in situ crystallization and photoreduction method.The fabricated Au@LDH/RGO composite was well characterized by different analytical instruments like PXRD,FTIR,Raman,XPS,EDX,FESEM,and TEM,suggesting strong interaction between the components of the ternary hybrid.Further,the Au@LDH/RGO catalyst shows the best hydrogen evolution reaction(HER),i.e.,918.76μmol/2 h(no.evolved H_(2)gas is 4.9903×10^(15)cm^(−2)s^(−1))with an ACE of 10.5%and excellent reusability up to 8 h with little change in activity.Additionally,the ternary nanohybrid depicts robust photocatalytic O_(2)reduction reaction performance,i.e.,24.3μmol/2 h of H_(2)O_(2)(SCC=0.23%),which goes via a superoxide radical mechanism as confirmed through tracing experiments.The observed high photocatalytic activity is attributed to the synergetic effect of both plasmonic Au nanoparticles and conjugatedΠ-skeleton of RGO,which resulted in high charge carrier density and reduction of the recombination process.This observation is well justified by Mott-Schottky,EIS,PL,and photocurrent measurements.Further,the HER performance was also tested under different hole scavengers to figure out their effect.The SPR effect of Au and conjugated cyclic carbon network of RGO plays a pivotal part in improving the H_(2)and H_(2)O_(2)generation ability of LDH under visible light illumination.
基金supported by the Natural Science Foundation of China(No.21776248 and 21676246)the Zhejiang Provincial Natural Science Foundation of China(No.LR17B060003)supported by the Fundamental Research Funds for the Central Universities.
文摘Developing highly efficient,Earth-abundant,and long-term stable electrocatalysts for the oxygen evolution reaction (OER) is of great importance for realizing industrial hydrogen generation from water splitting.Herein,a series of novel Fe and Nb co-doped β-Ni(OH)_(2)nanosheet arrays were successfully grown in situ on Ni foam via a chlorine etching method.The representative NiFe_(3)Nb_(2)-OH displayed outstanding OER performance with an overpotential of 294 mV to deliver 100 mA cm^(-2) in an alkaline electrolyte,outperforming other Ni related electrocatalysts.NiFe_(3)Nb_(2)-OH exhibited a stability of 90 h without obvious potential change at 50 mA cm^(-2).Significantly,the doped Fe and Nb effectively enhanced the electrochemical active area and electronic transfer capability of β-Ni(OH)_(2).Density functional theory (DFT) calculations indicated that the Gibbs free energy of the OER intermediates on the Fe,Nb co-doped β-Ni(OH)_(2)electrode was optimized.The tuned electronic interactions between Fe,Nb and Ni apparently boosted the OER performance of NiFe_(3)Nb_(2)-OH.These results demonstrated that Fe and Nb co-doped β-Ni(OH)_(2)is a highly efficient OER electrocatalyst in alkaline media.
基金supported by the 111 Project(Grant No.D17007)Henan Center for Outstanding Overseas Scientists(Grant No.GZS2022017)the National Science Foundation of China(Grant No.21908045,52072114,51922008 and 51872075).
文摘Electrocatalytic CO_(2) reduction reactions(CO_(2)RRs),an efficient method of converting carbon dioxide into valuable fuels and chemicals,are attractive as well as challenging.In this work,Cu_(2)O nanostructures with active facets(face-raised cubic structures(F-Cu_(2)O)with the(100)facet,octahedral structures(O-Cu_(2)O)with the(111)facet and edge-and corner-truncated octahedral structures(T-Cu_(2)O)with both the(100)and(111)facets)were synthesized by a wet chemical reduction method.The surface of Cu_(2)O nanostructures was reconstructed in situ to form Cu_(2)O/Cu with a highly active interface during the conversion of CO_(2) into C_(2)H_(4),which is named F-Cu_(2)O/Cu,O-Cu_(2)O/Cu and T-Cu_(2)O/Cu.The C_(2)H_(4) selectivity on Cu_(2)O/Cu catalysts follows the order of O-Cu_(2)O/Cu<F-Cu_(2)O/Cu<T-Cu_(2)O/Cu,and the faradaic efficiencies of C_(2)H_(4) are 11.2%,24.9%,and 58.0% at -1.1 V versus the reversible hydrogen electrode,respectively.The experimental results combined with operando surface-enhanced Raman spectroscopy reveal that the Cu_(2)O/Cu interface enhances *CO adsorption and decreases the activation energy of C-C coupling,which is also supported by density functional theory(DFT)calculations.This study will pave a feasible pathway for electrochemical energy storage and convention by crystal facet engineering and interface engineering.
基金supported by the National Natural Science Foundation of China(Grant No 21975255,51890862,U1605245,and 51425205)the National Key Research and Development Plan of Ministry of Science and Technology(Grant No 2016YFB0402104)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No XDB20000000)the NSF of Fujian Province(2019J01020758)the Youth Innovation Promotion Association CAS(303).
文摘A new mixed alkali hydro-isocyanurate,RbNa(HC_(3)N_(3)O_(3))·2H_(2)O,with the noncentrosymmetric space group Pna21(No.33),has been successfully grown by a hydrothermal method.The structure can be described as 2D wavy[Na(HC_(3)N_(3)O_(3))O_(4)]∞layers separated by Rb atoms.The UV-vis diffuse reflection measurement revealed that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O has a large band gap of 5.10 eV,corresponding to the UV cutoff edge of 241 nm.The polarizing microscope measurement of a micron-sized single crystal shows that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O has a large birefringence of 0.194.The powder SHG measurement indicated that RbNa(HC_(3)N_(3)O_(3))·2H_(2)O exhibits a strong SHG effect that is 5.3 times that of KH_(2)PO_(4)(KDP)and can realize phase-matching in the visible and UV region.Moreover,the differences in the SHG responses between RbNa(HC_(3)N_(3)O_(3))·2H_(2)O and two isostructural compounds have been investigated,which depend heavily on the structural modulation of the(HC_(3)N_(3)O_(3))2-group by cations.Meanwhile,the electronic structures and optical properties were well analyzed using DFT methods.
基金supported by the key Basic Research Programme of Hebei Province of China(17964401D)the National Natural Science Foundation of China(No.21603052,51771068 and 51771067)the Natural Science Foundation of Hebei Province(No.B201820167).
文摘TiO_(2)(B)nanotubes(NTs)were used as carriers to support metal Cu/Ni nanoparticles for the catalytic hydrolysis of ammonia borane(NH_(3)BH_(3),AB)under visible light.The TiO_(2)NTs were first prepared by the hydrothermal method and subsequently loaded with Cu/Ni metal nanoparticles by the impregnation reduction method.The structure,morphology,and chemical composition of the as-obtained catalysts were characterized by X-ray diffraction(XRD),scanning electron microscopy coupled with energy dispersive X-ray spectroscopy(SEM-EDX),transmission electron microscopy(TEM),inductively coupled plasma emission spectroscopy(ICP),and ultraviolet-visible spectroscopy(UV-Vis).The characterization results revealed that the metal nanoparticles were uniformly loaded on the surface of the TiO_(2)NTs,while the band gap of the catalyst was reduced significantly from 3.22 to 2.68 eV.The catalysts showed an excellent photocatalytic performance towards the hydrolysis of AB for H_(2)production.Thus,the H_(2)production rate of Cu_(0.64)Ni_(0.36)-TiO_(2)NTs reached 5763.86 mL g^(-1)min^(-1),with a total turnover frequency(TOF)of 15.90 mol H_(2)(mol cat)^(-1)min^(-1)for a loading volume of metal particles of 5.25 wt%.The results presented herein demonstrate that TiO_(2)(B)can be a potential photocatalyst for effective H_(2)production,and also provide a cheap and effective approach to improve the light-to-H_(2)energy conversion.
基金completed with the help of the West Light Foundation of the CAS(Grant No.2016-YJRC-2)the National Natural Science Foundation of China(Grant No.U1703127,61835014,and 51425206)+2 种基金the High-level Professional and Technical Personnel of Autonomous region,the Science and Technology Project of Urumqi(Grant No.G161020001)the Xinjiang Key Research and Development Program(Grant No.2016B02021)The authors also express their thanks to the“Fujian Institute of Innovation,CAS”for the support.
文摘A new deep-ultraviolet nonlinear optical crystal,Cs_(12)Zn_(4)(B_(5)O_(10))_(4),was synthesized via a high temperature solution method.The crystal structure was solved in the noncentrosymmetric space group(Cc,no.9).Owing to the cation size effect,from X_(3)ZnB_(5)O_(10)(X=Na,K,and Rb)to Cs_(12)Zn_(4)(B_(5)O_(10))_(4),the structure changes from centrosymmetric to noncentrosymmetric.Cs_(12)Zn_(4)(B_(5)O_(10))_(4) exhibits a 3D[ZnB_(5)O_(10)]_(∞) network,however,X_(3)ZnB_(5)O_(10)(X=Na,K,and Rb)exhibits a 2D[ZnB_(5)O_(10)]_(∞)layer.It is worth mentioning that Cs_(12)Zn_(4)(B_(5)O_(10))_(4) displays a short cutoff edge(below 185 nm),which is remarkable among the reported Zn-containing NLO crystals.Meanwhile,the compound exhibits a moderate SHG response and melts congruently.In addition,the relationship between its structure and NLO properties was also discussed in detail using the density functional theory(DFT)method.
基金financially supported by the National Natural Science Foundation of China(51579057 and 51779065)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(2016DX07)J.Liu acknowledges the support of the Doctoral Fund of the QUST,the Thousand Youth Talents Program of China,and the Natural Science Foundation of Shandong Province(No.ZR2018MB018).
文摘Herein,we report the synthesis of hybrid nanostructures obtained by densely growing MoS_(2)nanosheet layers on hydrophobic hollow carbon spheres(abbreviated as MoS_(2)-HCS)through a solvothermal method.The morphologies and compositions of the MoS_(2)-HCS hybrid are well investigated.The electrochemical performance of the MoS_(2)-HCS sphere is investigated in both supercapacitors and the hydrogen evolution reaction.
基金funding support from PhD Research Startup Foundation(ZKNUC2021017)Henan Province Science Foundation for Youth(242300420580)+1 种基金Key Scientific Research Projects of Colleges and Universities in Henan Province(24A530011)the funding support from National Natural Science Foundation of China(No.22108320,22268038).
文摘In the quest for amplifying the inherent capabilities of noble metals,crafting precise metal–support interfacial bonds stands as a challenging yet fruitful endeavor.Here,we introduce an approach to synthesize exceptionally small metal nanoparticles(NPs),which are securely anchored onto cobalt-based metal–organic framework(Co-MOF)nanosheets through a wet chemical method.The creation of metal–oxygen linkages between these Ir NPs and Co-MOF not only guarantees structural robustness but also ensures a generous exposure of active sites.Importantly,the distinct interface fine-tunes the electronic configuration of the composites by facilitating charge transfer along the Ir–O–Co pathway,consequently boosting the reaction dynamics.As a result,the hydrogen evolution reaction(HER)performance of our pioneering product,Ir@Co-MOF,in alkaline media,rivals that of the benchmark Pt/C catalyst and surpasses other recent noble metal catalysts.Theoretical analysis reveals that the exceptional HER efficiency of Ir@Co-MOF originates from the optimal adsorption energies for water and hydrogen,a consequence of electron re-allocation owing to its unique interfacial bond.
基金supported by the Mid-career Researcher Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(No.2019R1A2C2086747).
文摘The ever-increasing obligation of green and sustainable energy has intensified rigorous research on improving efficient electrochemical energy transition and storage systems.Herein,CoS_(2)prickly-pear-like sheet-intermingled metal carbide(Mo_(2)C and W_(2)C)hybrids were synthesized using a facile hydrothermal method.The fabricated hierarchical CoS_(2)-W_(2)C and CoS_(2)-Mo_(2)C hybrid structures were explored for their pseudo-capacitive behaviour by half-cell studies with specific capacities of 720 and 380 C g^(−1)at 2 A g^(−1),respectively,with great cycling stability.The synthesized CoS_(2)-W_(2)C and CoS_(2)-Mo_(2)C hybrid asymmetric supercapacitors demonstrated an elevated specific capacitance,reaching 423 F g^(−1)at a current density of 2 A g^(−1)within an extended voltage range of 1.6 V.Additionally,the highest energy density of 150 W h kg^(−1)was achieved at a maximum power density of 4.5 kW kg^(−1)along with a superior capacitance retention of 94.1%after 5000 cycles.As hydrogen evolution catalysts,the CoS_(2)-W_(2)C hybrid required small overpotentials of 50 and 42 mV,whereas the CoS_(2)-Mo_(2)C hybrid required 54 and 50 mV to deliver 10 mA cm^(−2)current density in acid and KOH solution,respectively.This study related to metal carbide-interconnected metal sulfide provides a promising opportunity for the fabrication/design and application of multifunctional electrocatalysts.
基金supported by the Science and Technology Major Project of Guangxi(AB16380030).
文摘Developing low-cost and efficient catalysts for hydrogen evolution is of great significance to solve the human energy crisis.In this work,ruthenium-nickel alloy is synthesized by a solvothermal method.The ruthenium-nickel alloy shows distinguished catalytic performance and durability for the hydrogen evolution reaction in alkaline solution(1 M KOH).Only 21,76,222 and 323 mV overpotentials are required to reach current densities of 10,100,1000 and 2000 mA cm^(-2).After 150 hours of a durability test at a current density of-400 mA cm^(-2),the alloy also shows outstanding durability.Density functional theory(DFT)further shows that ruthenium-nickel alloy composites can optimize the reaction barrier of alkaline hydrogen evolution.This study provides a valuable method for developing high-performance and lowprice alloy catalysts for hydrogen evolution.
基金National Natural Science Foundation of China(21571110)Natural Science Foundation of Zhejiang Province(LY18B010003)+1 种基金Ningbo Key Innovation Team(2014B81005)K.C.Wong Magna Fund in Ningbo University。
文摘Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits.Therefore,titanium-based materials have attracted great attention due to their high stability.Here,Na_(2)Li_(2)Ti_(6)O_(14)nanofibers as anode materials were prepared through a controlled electrospinning method.The Na_(2)Li_(2)Ti_(6)O_(14)nanofibers presented superior electrochemical performance with high rate capability and long cycle life and can be regarded as a competitive anode candidate for advanced Li-ion batteries.One-dimensional(1D)Na_(2)Li_(2)Ti_(6)O_(14)nanofibers are able to deliver a capacity of 128.5 mA h g^(-1)at 0.5C,and demonstrate superior high-rate charge-discharge capability and cycling stability(the reversible charge capacity is 77.8 mA h g^(-1)with a capacity retention of 99.45%at the rate of 10C after 800 cycles).The 1D structure is considered to contribute remarkably to increased rate capability and stability.This simple and scalable method indicates that the Na_(2)Li_(2)Ti_(6)O_(14)nanofibers have a practical application potential for high performance lithium-ion batteries.
基金supported by the National Natural Science Foundation of China[grant number 51772151,51761145103]the Nanjing University of Aeronautics and Astronautics PhD short-term visiting scholar project([2018]47)[grant number 190105DF06]the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘A double network nested foam composite with tunable electromagnetic wave absorption performance was fabricated via a carbonization,impregnation,and chemical vapor infiltration method.The research results indicated that the three-dimensional interconnected carbon foam was successfully enhanced by the SiC nanowire network.As expected,the electromagnetic absorption performance of the as-prepared SiC nanowire reinforced carbon foam(SiC_(nw)/CF)was greatly improved by the introduction of the SiC nanowires.The SiC_(nw)/CF composite prepared with a lower concentration of Ni catalyst possessed an excellent microwave absorption property with the lowest reflection loss value of-36.31 dB with a matched thickness of 2.60 mm accompanied by the widest effective bandwidth of 4.52 dB.An increase in catalyst concentration degraded the electromagnetic absorption ability to a certain extent.A potential microwave absorption schematic diagram was finally proposed,and it stated that the SiC nanowire network played an essential role in the improvement of the electromagnetic absorption properties.
基金supported by the National Natural Science Foundation of China(no.2177060378 and 21521005)the Program for Changjiang Scholars,Innovative Research Teams in Universities(no.IRT1205)the Fundamental Research Funds for the Central Universities(no.12060093063 and XK1803-05)。
文摘Transition metal phosphides are considered ideal alternatives for noble metal catalysts in hydrogen evolution reactions.In this study,amorphous NiCuFeP nanosheets were uniformly coated on self-supporting Cu_(3)P nanowire arrays through a facile electrodeposition method.The obtained_(3)D hierarchical NiCuFeP@Cu_(3)P/CF with good conductivity and abundant active sites was used as a hydrogen evolution reaction electrocatalyst.There are strong electronic interactions between each component of the material,as well as between the metal elements and P,which are conducive to improving the catalytic performance.
基金supported by the National Natural Science Foundation of China(52362036)the Science and Technology Plan Project of Gansu Province(23JRRA691).
文摘An oxygen reduction reaction(ORR)catalyst is a crucial component of metal–air batteries.Herein,modified carbon nanotubes are used to support iron phthalocyanine,followed by the fabrication of single-atom and cluster coexisting catalysts by the fast microwave method.The two catalysts have Fe–N_(5)and Fe–P–N_(4)coordination structures,respectively.Electrochemical tests show that the FeNC/Fe–N_(5)–C and FeNC/Fe–P–N_(4)–C catalysts have half-wave potentials of 0.906 and 0.886 V in an alkaline solvent,respectively.The Zn–air battery prepared with the FeNC/Fe–N_(5)–C catalyst has a specific capacity of 791 mA h g^(−1)and a maximum power density of 190 mW cm^(−2).DFT calculations show that the axial coordination bonds in FeNC/Fe–N_(5)–C and FeNC/Fe–P–N_(4)–C are conducive to the acceleration of the transfer of electrons.The d-band centers of the axial coordination Fe–N_(5)and Fe–P–N_(4)are closer to the Fermi level,confirming that the presence of the axial coordination bonds enhances the adsorption of the reaction intermediates and reduces the ORR barriers.
基金supported by the National Natural Science Foundation of China(21872148)Natural Science Foundation of Fujian Province(2022J06031)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(Grant No.2021ZR131).
文摘The development of multiple metal-organic framework(MOF)thin films with high lattice mismatch is still a challenging task.Herein we report a series of single and multiple(bi-varietal and tri-varietal)pillarlayered MOF thin films(surface-coordinated MOF thin films,SURMOFs)[Cu_(2)L_(2)dabco]_(n)(L=bdc,bpc and tpdc)with preferred[001]-orientation on the substrate surfaces using a liquid-phase epitaxial(LPE)layer by layer pump method.The single SURMOFs with the same c-lattice parameters but different a-and b-lattice parameters result in the successful growth of oriented multiple SURMOFs with high lattice mismatch(up to 77.8%).The vapor adsorption results show that the representative bi-varietal SURMOF with large lattice mismatch has different adsorption behavior from single SURMOFs,providing a new strategy to achieve tuning of the adsorption kinetics performance in sensing applications.
基金supported by the National Natural Science Foundation of China(contract 51872162 and 11890700)the Key R&D Innovation Program of Shandong Province-Major Innovation Project(2019TSLH0116).
文摘The reasonable design of electrode materials with heterojunctions and vacancies is a promising strategy to elevate their electrochemical performances.Herein,tin-based sulfide composites with heterojunctions and sulfur vacancies encapsulated by reduced graphene oxide(SnS_(2-x)P_(x)/RGO)were successfully designed and synthesized via a facile hydrothermal assisted phosphating method.The introduction of sulfur vacancies and construction of SnS-SnS2 heterojunctions were realized simultaneously by the phosphating process.The synergistic effect of the heterojunction,sulfur vacancy and phosphorus-doping could improve the conductivity,accelerate the ion transport dynamics,and enhance structural stability.Thus,high-rate,long-term cycling stability was observed for Li-half cells(337 mA h g^(-1) maintained after 3000 cycles at 10 A g^(-1))and Na-half cells(199 mA h g^(-1) maintained after 4000 cycles at 2 A g^(-1)).The design strategy can effectively improve the energy storage performance of tin based sulfides and can be extended to other metal sulfides.
