A Pt/graphene‐TiO2catalyst was prepared by a microwave‐assisted solvothermal method and was characterized by X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,cyclic voltammetry,and li...A Pt/graphene‐TiO2catalyst was prepared by a microwave‐assisted solvothermal method and was characterized by X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,cyclic voltammetry,and linear sweep voltammetry.The cubic TiO2particles were approximately60nm in size and were distributed on the graphene sheets.The Pt nanoparticles were uniformly distributed between the TiO2particles and the graphene sheet.The catalyst exhibited a significant improvement in activity and stability towards the oxygen reduction reaction compared with Pt/C,which resulted from the high electronic conductivity of graphene and strong metal‐support interactions.展开更多
A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting ...A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting the ultraviolet-visible spectroscopy technology and H+ concentration detector. Moreover, the amount of Na OH that effectively coordinates Pt4+ has been tentatively qualified and the heating parameters during the preparation process of Pt/C have also been optimized. As investigated, the optimized 20-(1/22)-140-2 Pt/C(20 wt%Pt;m(Pt):m(Na OH)=1/22;heating temperature: 140 °C, heating time: 2 h) exhibits higher electrocatalytic activity towards oxygen reduction reaction(ORR) than the commercial 20 wt% Pt/C(E-TEK) in acidic media. This work provides a theoretical reserve and technical accumulation for industrialized mass production of highly efficient Pt/C catalysts for ORR in proton exchange membrane fuel cells.展开更多
In order to obtain nanomaterials with superparamagnetism and high saturation magnetization, Mn-doped or Zn-doped superparamagnetic ferrite nanoclusters(Mn-FNs or Zn-FNs) were prepared by microwave-assisted solvotherma...In order to obtain nanomaterials with superparamagnetism and high saturation magnetization, Mn-doped or Zn-doped superparamagnetic ferrite nanoclusters(Mn-FNs or Zn-FNs) were prepared by microwave-assisted solvothermal method in this study. Preliminary investigations were performed by transmission electron microscopy(TEM) and dynamic light scattering(DLS) instrument to observe the morphology and measure the particle size, respectively. Afterwards, Zn-FNs were chosen to be further characterized in vitro due to their better morphology and dispersity than Mn-FNs. The subsequent characterizations included crystalline phase, metal content and magnetic properties by X-ray diffractometer(XRD), inductively coupled plasma-mass spectrometry(ICP-MS) and vibrating sample magnetometer(VSM), respectively. The results showed that Zn-FNs had a cluster-like structure assembled by multiple nanoparticles. Zn-FNs were spherical in shape with good dispersity and relatively uniform particle size. Zn was successfully doped in Zn-FNs which demonstrated spinel structure and excellent magnetic properties. Therefore, Zn-FNs had a favorable application prospect as a new type of magnetic nanomaterial.展开更多
基金supported by the National Natural Science Foundation of China(21376113)the Jiangsu Specially Appointed Professor Projectthe Graduate Student Scientific Research Innovation Projects in Jiangsu Province(KYZZ15_0384)~~
文摘A Pt/graphene‐TiO2catalyst was prepared by a microwave‐assisted solvothermal method and was characterized by X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,cyclic voltammetry,and linear sweep voltammetry.The cubic TiO2particles were approximately60nm in size and were distributed on the graphene sheets.The Pt nanoparticles were uniformly distributed between the TiO2particles and the graphene sheet.The catalyst exhibited a significant improvement in activity and stability towards the oxygen reduction reaction compared with Pt/C,which resulted from the high electronic conductivity of graphene and strong metal‐support interactions.
文摘A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting the ultraviolet-visible spectroscopy technology and H+ concentration detector. Moreover, the amount of Na OH that effectively coordinates Pt4+ has been tentatively qualified and the heating parameters during the preparation process of Pt/C have also been optimized. As investigated, the optimized 20-(1/22)-140-2 Pt/C(20 wt%Pt;m(Pt):m(Na OH)=1/22;heating temperature: 140 °C, heating time: 2 h) exhibits higher electrocatalytic activity towards oxygen reduction reaction(ORR) than the commercial 20 wt% Pt/C(E-TEK) in acidic media. This work provides a theoretical reserve and technical accumulation for industrialized mass production of highly efficient Pt/C catalysts for ORR in proton exchange membrane fuel cells.
基金National Natural Science Foundation of China(Grant No.81571779).
文摘In order to obtain nanomaterials with superparamagnetism and high saturation magnetization, Mn-doped or Zn-doped superparamagnetic ferrite nanoclusters(Mn-FNs or Zn-FNs) were prepared by microwave-assisted solvothermal method in this study. Preliminary investigations were performed by transmission electron microscopy(TEM) and dynamic light scattering(DLS) instrument to observe the morphology and measure the particle size, respectively. Afterwards, Zn-FNs were chosen to be further characterized in vitro due to their better morphology and dispersity than Mn-FNs. The subsequent characterizations included crystalline phase, metal content and magnetic properties by X-ray diffractometer(XRD), inductively coupled plasma-mass spectrometry(ICP-MS) and vibrating sample magnetometer(VSM), respectively. The results showed that Zn-FNs had a cluster-like structure assembled by multiple nanoparticles. Zn-FNs were spherical in shape with good dispersity and relatively uniform particle size. Zn was successfully doped in Zn-FNs which demonstrated spinel structure and excellent magnetic properties. Therefore, Zn-FNs had a favorable application prospect as a new type of magnetic nanomaterial.
