Shuyan Song

Folded Structured Graphene Paper for High Performance Electrode Materials

A novel method to fabricate graphene paper with folded structured graphene sheets is described. When used as an electrode for LIBs and supercapacitors, the as-prepared graphene paper can show much higher performances compared to conventional graphene paper fabricated by a flow-directed assembly method. The unique graphene paper obtained here is promising to act as a new kind of flexible electrode for wearable or rolling-up devices.

Pt@CeO2 Multicore@Shell Self-Assembled Nanospheres: Clean Synthesis, Structure Optimization, and Catalytic Applications

A clean nonorganic synthetic method has been developed to fabricate the uniform pomegranate-like Pt@CeO2 multicore@shell nanospheres in a large scale. Under the effective protection of Ar atmosphere the redox reaction just simply happened between Ce(NO3)3 and K2PtCl4 in an alkaline aqueous solution, in which no other reducing agents or surfactants were added. The as-obtained nanospheres exhibited excellent structure stability even being calcined at 600 °C for 5 h. Moreover, the as-obtained Pt@CeO2 multicore@shell nanospheres can be further supported on reduced graphene oxide (RGO) to form heterogeneous nanocatalyst, which has been successfully applied in the chemical reduction reaction of nitrophenol (NP) by ammonia borane (NH3BH3, dubbed as AB) instead of hazardous H2 or NaBH4.

Graphene oxide covalently grafted upconversion nanoparticles for combined NIR mediated imaging and photothermal/photodynamic cancer therapy

Theranostics, the integration of diagnostics and therapies, has become a new concept in the battles with various major diseases such as cancer. Here, we report a multifunctional nanoplatform, which is developed by covalently grafting core-shell structured upconversion nanoparticles (UCNPs) with nanographene oxide (NGO) via bifunctional polyethylene glycol (PEG), and then loading phthalocyanine (ZnPc) on the surface of NGO. The obtained UCNPs-NGO/ZnPc nanocomposites are not only be used as upconversion luminescence (UCL) imaging probes of cells and whole-body animals with high contrast for diagnosis, but also can generate cytotoxic singlet oxygen under light excitation for photodynamic therapy (PDT), as well as rapidly and efficiently convert the 808 nm laser energy into thermal energy for photothermal therapy (PTT). A remarkably improved and synergistic therapeutic effect compared to PTT or PDT alone is obtained, providing high therapeutic efficiency for cancer treatment. Therefore, benefiting from the unique multifunctional hybrid nanostructure, UCNPs-NGO/ZnPc nanocomposites developed herein are promising as an integrated theranostic probe for potential UCL image-guided combinatorial PDT/PTT of cancer.

One-dimensional channel-structured Eu-MOF for sensing small organic molecules and Cu2+ ion

Two new lanthanide metal–organic frameworks Ln(FBPT)(H2O)(DMF) (FBPT = 2′-fluoro-biphenyl-3,4′,5-tricarboxylate, Ln = Eu and Tb) were prepared under solvothermal conditions. Single crystal X-ray diffraction analyses reveal that the two compounds are isostructurally related with the same one-dimensional channel structure on the basis of FBPT as an organic linker. Herein, the Eu(FBPT)(H2O)(DMF) (EuL) is selected as a representative sample for luminescent measurements. Study of the photoluminescence properties reveals that the EuL exhibits red emission, corresponding to the 5D0 → 7FJ (J = 1–4) transitions of the Eu3+ ion under UV light excitation. Most interestingly, when this compound was immersed in the different organic solvents and metal ion DMF solutions, it shows highly selective and sensitive sensing for small organic molecules and Cu2+ ions. In connection to this, a probable sensing mechanism was also discussed in this paper.

Formation of Onion-Like NiCo2S4 Particles via Sequential Ion-Exchange for Hybrid Supercapacitors

Onion-like NiCo2 S4 particles with unique hollow structured shells are synthesized by a sequential ion-exchange strategy. With the structural and compositional advantages, these unique onion-like NiCo2 S4 particles exhibit enhanced electrochemical performance as an electrode material for hybrid supercapacitors.

Synthesis, characterization and assembly of BiOCl nanostructure and their photocatalytic properties

In this article, a two-dimensional (2D) nanoplate and a 3D hierarchical structure of BiOCl were synthesized through a simple sonochemical route. Compared with previous preparation methods, the 2D nanoplates can be prepared at a relatively short time (about 30 min) with low energy used. Additionally, these 2D nanoplates can easily assemble into a 3D hierarchical structure with the surfactant reagents. The obtained products were well crystallized and subsequently characterized by a range of methods, such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission microscopy (HRTEM), selected area electron diffraction (SAED) and Raman spectroscopy. A possible mechanical growth route was also proposed based on the experiments. The photocatalytic properties of the prepared samples were further investigated by photocatalytic decomposition of Methene Orange (MO) dye, which indicated that the 3D hierarchical structure can effectively improve photocatalytic activity.

Crystallization design of MnO2 towards better supercapacitance

Nanostructured manganese oxides with different crystallization behaviors were fabricated by a simple redox reaction between KMnO4 and NaNO2 aqueous solution. MnO2 nanostructures with sphere-, rod-, wire-, plate- and flower-like morphologies were crystallized, and the relationship between crystallization characteristics and their electrochemical performances were studied. The electrochemical energy storage behaviors of these samples were investigated by cyclic voltammetry and galvanostatic charge–discharge measurements processed using noncorrosive Na2SO4 as the electrolyte. A maximum specific capacitance 200 F g−1 was obtained for poorly crystallized α-MnO2 at a current density of 1 A g−1. For different crystallographic MnO2 phases, their specific capacitance values increase in the order: β < γ < δ < α, meanwhile, for any particular MnO2 phase, their electrochemical energy storage performances decrease with increasing crystalline nature and particle size.

Green synthesis of Pt/CeO2/graphene hybrid nanomaterials with remarkably enhanced electrocatalytic properties

We developed a facile strategy for clean synthesis of Pt/CeO(2)/graphene nanomaterials with remarkably enhanced catalytic properties. The graphene oxide (GO) could be used as an oxidant to oxidize Ce(3+) into CeO(2) NPs, and l-lysine was used as a linker to realize the in situ growth of Pt NPs around CeO(2) NPs dispersed on graphene.

Selectively Deposited Noble Metal Nanoparticles on Fe3O4/Graphene Composites: Stable, Recyclable, and Magnetically Separable Catalysts

A simple, efficient, and general approach was developed to selectively deposit noble metal (Pt, Pd, or PtPd) nanoparticles 3-5 nm in size on magnetite/graphene composites. The biomolecule L-lysine with two kinds of functional groups (NH(2) and COOH) played the key role of connecter between noble metals and Fe(3)O(4)/graphene composites. These composites were characterized by TEM, XRD, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The results indicated that the noble metals are mostly dispersed on the magnetite surfaces of the composites. The as-obtained composites are ideal recyclable catalysts for liquid-phase reactions owing to their stability and efficient magnetic separation. Among these catalysts, the PtPd-based composites exhibited the highest activity and resistance to poisoning during the catalytic reduction of 4-nitrophenol to 4-aminophenol by NaBH(4). Such hybrid catalysts obtained by this simple, efficient method are expected to find use in industrial applications, where separation and recycling are critically required to reduce cost and waste production.

A europium(III) based metal–organic framework: bifunctional properties related to sensing and electronic conductivity

The accessible interspace of [Eu4(BPT)4(DMF)2(H2O)8] (EuL) metal–organic framework (MOF) based host materials can serve as good candidates for loading of a variety of guest molecules. In this regard, two functional properties, sensing and electronic conductivity of EuL MOF were systematically studied in this contribution. The photoluminescent properties reveal that the EuL exhibits characteristic red emission of Eu3+ ion, and presents highly detectable luminescence responses for Cu2+ ions and acetone molecules in DMF solution. For the studies of electrical properties, they were focused on the electronic conductivities of I2-incorporated EuL in anhydrous media and at different temperatures. With the increase of temperature from 25 to 80 °C, the I2-incorporated EuL showed significant changes in conductivities from 8.27 × 10−7 S cm−1 to 2.71 × 10−5 S cm−1. Meanwhile, the activation energy (Ea) was for the first time estimated for iodine-element-incorporated MOF with the help of Arrhenius plots. The successful achievements of the impedance measurements and analyses for I2-incorporated EuL prove for the first time that iodine-element-incorporated MOF can also be used for studies of conductivity under anhydrous conditions and at moderate temperature.