Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires.Herein,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated.Au-Pd ...Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires.Herein,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated.Au-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping processes.The effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were articulated.Generally,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical structures.The kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy nanostructures.In addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.展开更多
Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structur...Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structure via a self-synthesized single precursor and subsequent calcination at high temperature.With the support of oleylamine,the precursor is structurally targeted to engineer the Fe7Se8 microstructure,featuring nanorod bundles arranged along the longitudinal direction.Because of their ordered hierarchical structure,the Fe7Se8 nanorod bundles deliver a high reversible capacity of 300 m Ah g^-1 at 0.5 A g^-1,along with exceptional rate capability up to 20 A g^-1 and long-term cycle life over 8000 cycles,which represents the highest stability of Fe7Se8 anodes for sodium-ion batteries reported to date.The feasibility of the present strategy to prepare metal selenide structures highlights its promising potential for the rational and effective engineering of electrode materials responsible for the electrochemical performance of energy storage systems.展开更多
In this work,a simple and facile one-pot oleylamine solvothermal synthetic method was developed to synthesize Cu2ZnSnS4（CZTS） nanocrystals.And the Cu2ZnSn（S,Se）4（CZTSSe） thin films were prepared by selenizing CZ...In this work,a simple and facile one-pot oleylamine solvothermal synthetic method was developed to synthesize Cu2ZnSnS4（CZTS） nanocrystals.And the Cu2ZnSn（S,Se）4（CZTSSe） thin films were prepared by selenizing CZTS nanocrystals.The obtained CZTS nanocrystals and CZTSSe films were studied using X-ray diffraction（XRD）,transmission electron microscopy（TEM）,scanning electron microscopy（SEM）,energy-dispersive X-ray spectroscopy（EDX）,and ultraviolet–visible spectrophotometer（UV–Vis）.TEM results show that the sphere–like CZTS nanoparticles with diameter between 12 and 35 nm are polydispersed.XRD studies indicate that the prepared CZTS nanocrystals form kesterite crystal structure,and the CZTSSe films with kesterite crystal structure are also obtained at the annealing temperatures of 500 and550 °C.In particular after annealing at 500 °C for 20 min,the CZTSSe film exhibits a smooth,uniform,crack-free,and large-grained topography and possesses Cu-poor and Sn-rich composition.Moreover,it shows strong optical absorption from visible to near-infrared（IR） region,and its optical band gap（Eg） is found to be about 1.44 e V.展开更多
A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of ...A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.展开更多
High-quality II-VI semiconductor ZnSe nanowires were facilely prepared in the oleic acid and oleylamine mixed solution at low temperatures of 130°C-200°C through an Ag2Se-catalyzed growth mechanism. Oleylami...High-quality II-VI semiconductor ZnSe nanowires were facilely prepared in the oleic acid and oleylamine mixed solution at low temperatures of 130°C-200°C through an Ag2Se-catalyzed growth mechanism. Oleylamine served as an effective reducing agent and a surfactant in the synthesis. Many of the resultant nanowires were terminated by an Ag2Se catalyst particle at one of their ends, confirming that the nanowire growth followed a catalytic mechanism. The crystal structure of Ag2Se catalyst was examined, which exhibited a metastable tetragonal phase, not the common orthorhombic phase. Meanwhile, the optical properties of as-synthesized ZnSe nanowire solid powder were evaluated by the UV-Visible diffuse reflectance and photoluminescence spectroscopy and a significant blue shift was observed compared to the bulk ZnSe with a band gap of 2.7 eV. This work would provide an alternative and effective catalytic route for the preparation of one-dimensional (1D) nanostructures of ZnSe and other metal selenides.展开更多
Waste plastics recycling and oil/organics remediation are environmental issues of global concern.In this work,a protectant was introduced,for the first time,to make highly efficient catalysts for pyrolysis of waste pl...Waste plastics recycling and oil/organics remediation are environmental issues of global concern.In this work,a protectant was introduced,for the first time,to make highly efficient catalysts for pyrolysis of waste plastics into carbon nanotubes(CNTs)with high yield.By using waste polyethylene,Co(NO_(3))_(2) and oleylamine respectively as carbon source,catalyst precursor and protectant,a yield as high as 59.0%was achieved.The CNTs exhibited a high adsorption capacity for methylene blue(up to 107.1 mg/g).Furthermore,by combining the CNTs with graphene oxide,a graphene-CNT aerogel with a low density of8.2 mg/cm^(3)and high porosity of 96.0%was successfully prepared.It showed excellent hydrophobicity and mechanical stability,as well as high adsorption capacity of 289-410 g/g oil/organic solvent,which was much higher than most of these achieved by carbon-based three-dimensional materials reported previously,making the as-prepared aerogel a very promising adsorbent for oil/water separation.展开更多
基金support from the National Natural Science Foundation of China(Nos.21703104 and 91956109)Zhejiang Provincial Natural Science Foundation of China(No.2022XHSJJ002)+2 种基金Hangzhou Municipal Funding(No.TD2022004)Nanjing Tech University(No.39837131)SICAM Fellowship from Jiangsu National Synergetic Innovation Centre for Advanced Materials。
文摘Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires.Herein,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated.Au-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping processes.The effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were articulated.Generally,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical structures.The kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy nanostructures.In addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.
基金the National Natural Science Foundation of China(21871164)the Natural Science Foundation of Shandong Province(ZR2019MB024)the Taishan Scholar Project of Shandong Province(no.ts201511004).
文摘Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structure via a self-synthesized single precursor and subsequent calcination at high temperature.With the support of oleylamine,the precursor is structurally targeted to engineer the Fe7Se8 microstructure,featuring nanorod bundles arranged along the longitudinal direction.Because of their ordered hierarchical structure,the Fe7Se8 nanorod bundles deliver a high reversible capacity of 300 m Ah g^-1 at 0.5 A g^-1,along with exceptional rate capability up to 20 A g^-1 and long-term cycle life over 8000 cycles,which represents the highest stability of Fe7Se8 anodes for sodium-ion batteries reported to date.The feasibility of the present strategy to prepare metal selenide structures highlights its promising potential for the rational and effective engineering of electrode materials responsible for the electrochemical performance of energy storage systems.
基金financially supported by the National Natural Science Foundation of China(Nos.11564027 and 51262020)the Scientific Research Foundation of the Higher Education Institutions of Inner Mongolia Autonomous Region of China(No.NJZY16379)
文摘In this work,a simple and facile one-pot oleylamine solvothermal synthetic method was developed to synthesize Cu2ZnSnS4（CZTS） nanocrystals.And the Cu2ZnSn（S,Se）4（CZTSSe） thin films were prepared by selenizing CZTS nanocrystals.The obtained CZTS nanocrystals and CZTSSe films were studied using X-ray diffraction（XRD）,transmission electron microscopy（TEM）,scanning electron microscopy（SEM）,energy-dispersive X-ray spectroscopy（EDX）,and ultraviolet–visible spectrophotometer（UV–Vis）.TEM results show that the sphere–like CZTS nanoparticles with diameter between 12 and 35 nm are polydispersed.XRD studies indicate that the prepared CZTS nanocrystals form kesterite crystal structure,and the CZTSSe films with kesterite crystal structure are also obtained at the annealing temperatures of 500 and550 °C.In particular after annealing at 500 °C for 20 min,the CZTSSe film exhibits a smooth,uniform,crack-free,and large-grained topography and possesses Cu-poor and Sn-rich composition.Moreover,it shows strong optical absorption from visible to near-infrared（IR） region,and its optical band gap（Eg） is found to be about 1.44 e V.
基金National Natural Science Foundation of China(21067004)Young Science Foundation of Jiangxi Province Education Office (GJJ10150)Open Foundation of State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University(200906)
基金Supported by the National Natural Science Foundation of China（Nos.21772001, 21372008）, the Natural Science Foundation of Education Administration of Anhui Province, China（No.KJ2016A267）, the Special and Excellent Research Fund of Anhui Normal Universit and the Doctoral Scientific Research Foundation of Anhui Normal University, China（No.2016XJJ110）.
文摘A convenient and efficient method was developed for the synthesis of 2,2＇-（arylmethylene）bis（3-hydrox- ycyclohex-2-enone） derivatives via the oleylamine-catalyzed tandem Knoevenagel/Michael addition reactions of aromatic aldehydes and cyclohexane-1,3-diones. This transformation proceeded without any metal catalyst in non-toxic solvent at room temperature with high isolated yields. A plausible mechanism for this process was pro- posed.
文摘High-quality II-VI semiconductor ZnSe nanowires were facilely prepared in the oleic acid and oleylamine mixed solution at low temperatures of 130°C-200°C through an Ag2Se-catalyzed growth mechanism. Oleylamine served as an effective reducing agent and a surfactant in the synthesis. Many of the resultant nanowires were terminated by an Ag2Se catalyst particle at one of their ends, confirming that the nanowire growth followed a catalytic mechanism. The crystal structure of Ag2Se catalyst was examined, which exhibited a metastable tetragonal phase, not the common orthorhombic phase. Meanwhile, the optical properties of as-synthesized ZnSe nanowire solid powder were evaluated by the UV-Visible diffuse reflectance and photoluminescence spectroscopy and a significant blue shift was observed compared to the bulk ZnSe with a band gap of 2.7 eV. This work would provide an alternative and effective catalytic route for the preparation of one-dimensional (1D) nanostructures of ZnSe and other metal selenides.
基金supported by National Natural Science Foundation of China(Nos.51872210,51672194)Program for Innovative Teams of Outstanding Young and Middle-aged Researchers in the Higher Education Institutions of Hubei Province(No.T201602)Key Program of Natural Science Foundation of Hubei Province,China(No.2017CFA004)。
文摘Waste plastics recycling and oil/organics remediation are environmental issues of global concern.In this work,a protectant was introduced,for the first time,to make highly efficient catalysts for pyrolysis of waste plastics into carbon nanotubes(CNTs)with high yield.By using waste polyethylene,Co(NO_(3))_(2) and oleylamine respectively as carbon source,catalyst precursor and protectant,a yield as high as 59.0%was achieved.The CNTs exhibited a high adsorption capacity for methylene blue(up to 107.1 mg/g).Furthermore,by combining the CNTs with graphene oxide,a graphene-CNT aerogel with a low density of8.2 mg/cm^(3)and high porosity of 96.0%was successfully prepared.It showed excellent hydrophobicity and mechanical stability,as well as high adsorption capacity of 289-410 g/g oil/organic solvent,which was much higher than most of these achieved by carbon-based three-dimensional materials reported previously,making the as-prepared aerogel a very promising adsorbent for oil/water separation.
