Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are syn...Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo,which show strong light absorption from NIR-I to NIR-II biowindows with the photothermal conversion efficiencies of 20.4%under 808 nm laser and 32.7%under 1064 nm laser.Pt Cu nanosheets functionalized with folic acidmodified thiol-poly(ethylene glycol)(SH-PEG-FA)present good biocompatibility and 4T1 tumor-targeted effect,which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-I and NIR-II biowindows.Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.展开更多
The rigorous operating condition of proton exchange membrane fuel cells(PEMFCs)poses a substantial hurdle for the long-term stability of Pt-based alloy catalysts;thus,the development of Pt-alloy catalysts with unique ...The rigorous operating condition of proton exchange membrane fuel cells(PEMFCs)poses a substantial hurdle for the long-term stability of Pt-based alloy catalysts;thus,the development of Pt-alloy catalysts with unique morphologies is crucial for enhancing the stability of PEMFCs.In this study,we synthesized a novel PtCu nano-dendrite(PtCuND)catalyst through a facile,one-step solvothermal process.The sub-nanometer particles and nanopores within this catalyst facilitate enhanced mass transport.In PEM single-cell tests,the PtCuND catalyst displays high activity and robust stability,achieving a mass activity of 0.65 A mgPt^(–1).Notably,after accelerated durability tests,the mass activity and the voltage at 0.8 A cm^(–2)of PtCuND exhibits only minimal decreases of 18.5%and 9 mV,respectively.The combined experimental results and theoretical calculations conclusively illustrate the optimized adsorption of oxygen species and the impact of compressive strain on the catalyst surface.The enhanced durability can be attributed to the maintained nano-dendritic morphology and the strengthened interaction within the Pt-Cu bonds.This work not only enhances the stability of PEMFCs but also provides a robust foundation for the future scaling up of catalyst production,paving the way for widespread application in sustainable energy systems.展开更多
利用溶剂热法,在N,N-二甲基甲酰胺(DMF)溶剂中共同还原乙酰丙酮铂(Pt(acac)2)和乙酰丙酮铜(Cu(acac)_2)制备PtCu八面体合金催化剂.PtCu_2八面体表现出明显的晶格收缩、较高比例的非氧化态Pt单质和较高的电子结合能,进而表现出较弱的含...利用溶剂热法,在N,N-二甲基甲酰胺(DMF)溶剂中共同还原乙酰丙酮铂(Pt(acac)2)和乙酰丙酮铜(Cu(acac)_2)制备PtCu八面体合金催化剂.PtCu_2八面体表现出明显的晶格收缩、较高比例的非氧化态Pt单质和较高的电子结合能,进而表现出较弱的含氧物种吸附强度和较低的d带中心位置.系统研究结构导向剂对PtCu合金形貌影响.在半电池测试中,由于PtCu_2具有均匀分散的规则八面体形貌结构,导致在0.9 V vs.RHE处氧还原(ORR)的质量比活性和面积比活性分别是Pt/C(JM)的6.3和27.2倍,并在加速衰减测试后其ORR的质量比活性仍达到Pt/C(JM)的4.5倍.展开更多
Supported PtCu alloys have been broadly applied in heterogeneous catalysis and electrocatalysis owing to their excellent catalytic performance and high CO tolerance. It is important to analyze the outermost surface c...Supported PtCu alloys have been broadly applied in heterogeneous catalysis and electrocatalysis owing to their excellent catalytic performance and high CO tolerance. It is important to analyze the outermost surface composition of the supported alloy nanoparticles to understand the nature of the catalytically active sites. In this paper, homogeneous face-centered cubic PtCu nanoparticles with a narrow particle size distribution were successfully fabricated and dispersed on a high-surface-area Ti〇2 powder support. The samples were oxidized and reduced in situ and then introduced into the ultrahigh vacuum chamber to measure the topmost surface composition by high-sensitivity low-energy ion scattering spectroscopy, and to determine the oxidation states of the elements by X-ray photoelectron spectroscopy. The surface composition and morphology, elemental distribu-tion, and oxidation states of the components were found to be significantly affected by the support and treatment conditions. The PtCu is de-alloyed upon oxidation with CuO wetting on the TiO2 sur-face and re-alloyed upon reduction. Phase diagrams of the surface composition and the bulk com-position were plotted and compared for the supported and unsupported materials.展开更多
通过离子束溅射技术(IBS)制备了不同厚度比的PtCu/LaOx-C和LaOx/PtCu-C载体型双层膜电极;采用三电极体系测试了样品的阴极析氢极化曲线,并通过交换电流密度(i0)和分解电势(Ed)的求算结果优选出最优样品;采用XRD分析了最优样品的物相结...通过离子束溅射技术(IBS)制备了不同厚度比的PtCu/LaOx-C和LaOx/PtCu-C载体型双层膜电极;采用三电极体系测试了样品的阴极析氢极化曲线,并通过交换电流密度(i0)和分解电势(Ed)的求算结果优选出最优样品;采用XRD分析了最优样品的物相结构信息;采用SEM及EDS研究了各元素的含量分布。结果表明:PtCu层与LaOx层的沉积时间比为5∶5的PtCu/LaOx-C载体型双层膜电极析氢催化性能最优,平衡状态下的分解电势为-0.204(V vs SCE),交换电流密度达到了147.0μA/cm2;双层结构薄膜中,Cu与Pt形成了合金,而LaOx能降低Pt的晶粒尺寸,并促进Pt(111)择优取向生长。展开更多
以反式二氯二胺合铂(trans-PtCl2(NH3)2)为Pt源,溴化亚铜(CuBr)为Cu源,在油胺(OAm)体系中采用一锅法快速制备得到笼状PtCu3空心结构,同时用XRD,TEM,HRTEM和高角环形暗场扫描透射电子显微技术【HAADF-STEM,high angle annular dark field...以反式二氯二胺合铂(trans-PtCl2(NH3)2)为Pt源,溴化亚铜(CuBr)为Cu源,在油胺(OAm)体系中采用一锅法快速制备得到笼状PtCu3空心结构,同时用XRD,TEM,HRTEM和高角环形暗场扫描透射电子显微技术【HAADF-STEM,high angle annular dark field(HAADF)scanning transmission electron microscopy(STEM)】。对产物的结构及形貌进行动态的,多角度的表征,所得PtCu3空心结构对温度敏感,过高的温度会加快原子的扩散速率,导致空心结构坍塌。展开更多
Proton exchange membrane fuel cell and direct methanol fuel cells have gained more attention due to high-energy density,remarkable conversion efficiency,and low emission.However,their widely practical application was ...Proton exchange membrane fuel cell and direct methanol fuel cells have gained more attention due to high-energy density,remarkable conversion efficiency,and low emission.However,their widely practical application was hindered by the high usage,limited sources,and high price of Pt catalysts.To achieve more cost-effective catalytic systems,PtCu-based multi-metallic nanoparticles are highly efficient for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).The incorporation of non-noble Cu metal can alter the properties of hybrids by forming new facets,planes,edges to promote the cleavage or formation of chemical bonds in catalytic reaction.This is a rapid growing area with numerous contributions from the interdisciplinary areas of nanocatalysis.This paper has summarized the recent progress in the past two years,in synthesizing PtCu-based alloys with various composition and morphologies,and critically discussed the effect of the catalyst preparation method,metal precursor,surfactant,reductant and heating temperature on nanostructure and electronic configuration.The important role of the composition,size,and morphology of PtCu bimetallic catalysts for electro oxidation reactions has been further established for structure-dependency studies.The challenges and perspectives of nanocatalysts for ORR and MOR discussed in this work is to provide further insights into rational design for cost-effective materials for energy.展开更多
基金the National Natural Science Foundation of China(Nos.22275096,W2432015)Natural Science Key Fund for Universities in Jiangsu Province(No.22KJA430007)Qinglan Project of Jiangsu Province of China。
文摘Broadband photothermal and photoacoustic agents in the near-infrared(NIR)biowindow are of significance for cancer phototheranostics.In this work,Pt Cu nanosheets with an average lateral size of less than 10 nm are synthesized as NIR photothermal and photoacoustic agents in vivo,which show strong light absorption from NIR-I to NIR-II biowindows with the photothermal conversion efficiencies of 20.4%under 808 nm laser and 32.7%under 1064 nm laser.Pt Cu nanosheets functionalized with folic acidmodified thiol-poly(ethylene glycol)(SH-PEG-FA)present good biocompatibility and 4T1 tumor-targeted effect,which give high-contrast photoacoustic imaging and efficient photothermal ablation of 4T1 tumor in both NIR-I and NIR-II biowindows.Our work significantly broadens applications of noble metal-based nanomaterials in the fields of cancer phototheranostics by rationally designing their structures and modulating their physicochemical properties.
文摘The rigorous operating condition of proton exchange membrane fuel cells(PEMFCs)poses a substantial hurdle for the long-term stability of Pt-based alloy catalysts;thus,the development of Pt-alloy catalysts with unique morphologies is crucial for enhancing the stability of PEMFCs.In this study,we synthesized a novel PtCu nano-dendrite(PtCuND)catalyst through a facile,one-step solvothermal process.The sub-nanometer particles and nanopores within this catalyst facilitate enhanced mass transport.In PEM single-cell tests,the PtCuND catalyst displays high activity and robust stability,achieving a mass activity of 0.65 A mgPt^(–1).Notably,after accelerated durability tests,the mass activity and the voltage at 0.8 A cm^(–2)of PtCuND exhibits only minimal decreases of 18.5%and 9 mV,respectively.The combined experimental results and theoretical calculations conclusively illustrate the optimized adsorption of oxygen species and the impact of compressive strain on the catalyst surface.The enhanced durability can be attributed to the maintained nano-dendritic morphology and the strengthened interaction within the Pt-Cu bonds.This work not only enhances the stability of PEMFCs but also provides a robust foundation for the future scaling up of catalyst production,paving the way for widespread application in sustainable energy systems.
文摘利用溶剂热法,在N,N-二甲基甲酰胺(DMF)溶剂中共同还原乙酰丙酮铂(Pt(acac)2)和乙酰丙酮铜(Cu(acac)_2)制备PtCu八面体合金催化剂.PtCu_2八面体表现出明显的晶格收缩、较高比例的非氧化态Pt单质和较高的电子结合能,进而表现出较弱的含氧物种吸附强度和较低的d带中心位置.系统研究结构导向剂对PtCu合金形貌影响.在半电池测试中,由于PtCu_2具有均匀分散的规则八面体形貌结构,导致在0.9 V vs.RHE处氧还原(ORR)的质量比活性和面积比活性分别是Pt/C(JM)的6.3和27.2倍,并在加速衰减测试后其ORR的质量比活性仍达到Pt/C(JM)的4.5倍.
基金supported by the National Basic Research Program of China(973 Program,2013CB933102)the National Natural Science Foundation of China(21273178,21573180,91545204)Xiamen-Zhuoyue Biomass Energy Co.Ltd~~
文摘Supported PtCu alloys have been broadly applied in heterogeneous catalysis and electrocatalysis owing to their excellent catalytic performance and high CO tolerance. It is important to analyze the outermost surface composition of the supported alloy nanoparticles to understand the nature of the catalytically active sites. In this paper, homogeneous face-centered cubic PtCu nanoparticles with a narrow particle size distribution were successfully fabricated and dispersed on a high-surface-area Ti〇2 powder support. The samples were oxidized and reduced in situ and then introduced into the ultrahigh vacuum chamber to measure the topmost surface composition by high-sensitivity low-energy ion scattering spectroscopy, and to determine the oxidation states of the elements by X-ray photoelectron spectroscopy. The surface composition and morphology, elemental distribu-tion, and oxidation states of the components were found to be significantly affected by the support and treatment conditions. The PtCu is de-alloyed upon oxidation with CuO wetting on the TiO2 sur-face and re-alloyed upon reduction. Phase diagrams of the surface composition and the bulk com-position were plotted and compared for the supported and unsupported materials.
文摘通过离子束溅射技术(IBS)制备了不同厚度比的PtCu/LaOx-C和LaOx/PtCu-C载体型双层膜电极;采用三电极体系测试了样品的阴极析氢极化曲线,并通过交换电流密度(i0)和分解电势(Ed)的求算结果优选出最优样品;采用XRD分析了最优样品的物相结构信息;采用SEM及EDS研究了各元素的含量分布。结果表明:PtCu层与LaOx层的沉积时间比为5∶5的PtCu/LaOx-C载体型双层膜电极析氢催化性能最优,平衡状态下的分解电势为-0.204(V vs SCE),交换电流密度达到了147.0μA/cm2;双层结构薄膜中,Cu与Pt形成了合金,而LaOx能降低Pt的晶粒尺寸,并促进Pt(111)择优取向生长。
文摘以反式二氯二胺合铂(trans-PtCl2(NH3)2)为Pt源,溴化亚铜(CuBr)为Cu源,在油胺(OAm)体系中采用一锅法快速制备得到笼状PtCu3空心结构,同时用XRD,TEM,HRTEM和高角环形暗场扫描透射电子显微技术【HAADF-STEM,high angle annular dark field(HAADF)scanning transmission electron microscopy(STEM)】。对产物的结构及形貌进行动态的,多角度的表征,所得PtCu3空心结构对温度敏感,过高的温度会加快原子的扩散速率,导致空心结构坍塌。
基金supported by the National Natural Science Foundation(22078365,22008262)the Natural Science Foundation of Shandong Province(ZR2020QB187)+3 种基金the Postdoctoral Research Fun ding of Shand ong Province(201703016)the Qingdao Postdoctoral Research Funding(BY20170210)the"Fundamental Research Funds for the Central Universities"and"the Development Fund of State Key Laboratory of Heavy Oil Processing"(18CX02145A,17CX02017A,20CX02204A)the new faculty start-up funding from the China University of Petroleum(YJ201601058).
文摘Proton exchange membrane fuel cell and direct methanol fuel cells have gained more attention due to high-energy density,remarkable conversion efficiency,and low emission.However,their widely practical application was hindered by the high usage,limited sources,and high price of Pt catalysts.To achieve more cost-effective catalytic systems,PtCu-based multi-metallic nanoparticles are highly efficient for the oxygen reduction reaction(ORR)and methanol oxidation reaction(MOR).The incorporation of non-noble Cu metal can alter the properties of hybrids by forming new facets,planes,edges to promote the cleavage or formation of chemical bonds in catalytic reaction.This is a rapid growing area with numerous contributions from the interdisciplinary areas of nanocatalysis.This paper has summarized the recent progress in the past two years,in synthesizing PtCu-based alloys with various composition and morphologies,and critically discussed the effect of the catalyst preparation method,metal precursor,surfactant,reductant and heating temperature on nanostructure and electronic configuration.The important role of the composition,size,and morphology of PtCu bimetallic catalysts for electro oxidation reactions has been further established for structure-dependency studies.The challenges and perspectives of nanocatalysts for ORR and MOR discussed in this work is to provide further insights into rational design for cost-effective materials for energy.
