Novel porous starfish-like Co3O4@nitrogen-doped carbon as an advanced anode for lithium-ion batteries

A Co-based metal-organic framework （Co-MOF） with a unique three-dimensional starfish-like nanostructure was successfully synthesized using a simple ultrasonic method. After subsequent carbonization and oxidation, a nanocomposite of nitrogen-doped carbon with a Co3O4 coating （Co3O4@N-C） with a porous starfish-like nanostructure was obtained. The final hybrid exhibited excellent lithium storage performance when evaluated as an anode material in a lithiumion battery. A remarkable and stable discharge capacity of 795 mAh·g^-1 was maintained at 0.5 A·g^-1 after 300 cycles. Excellent rate capability was also obtained. In addition, a full Co3O4@N-C/LiFePO4 battery displayed stable capacity retention of 95% after 100 cycles. This excellent lithium storage performance is attributed to the unique porous starfish-like structure, which effectively buffers the volume expansion that occurs during Li^＋ insertion/deinsertion. Meanwhile, the nitrogendoped carbon coating enhances the electrical conductivity and provides a buffer layer to accommodate the volume change and accelerate the formation of a stable solid electrolyte interface layer.

Controlled Preparation and Formation Mechanism of Hydroxyapatite Nanoparticles under Different Hydrothermal Conditions

Hydroxyapatite （HAP） nanoparticles with uniform morphologies and controllable size were synthesized successfully by molecular template hydrothermal approach. The organic alcohols including ethanol, glycol, glycerol and butanol were used as templates to regulate the nucleation and crystal growth. The synthesized powders were characterized by X-ray diffraction, Fourier infrared spectrum and trans- mission electron microscopy. The results showed that the obtained HAP particles were uniform rod-like crystals, and the template molecular structures had significant effect on the morphology and size of HAP particles. The template molecules with longer hydrophobic groups resulted in longer particle length and larger aspect ratio. Compared with the concentration of template molecules, the template molecular structure showed larger influence on controlling the HAP morphology and size. Furthermore, the for- mation mechanism of these rod-like HAP particles prepared by alkyl alcohol templates was discussed. Moreover, hydrothermal treatment temperature and time could be also used for controlled preparation of HAP nanoparticles.

Multifunctional Reduced Graphene Oxide Hydrogel as Drug Carrier for Localized and Synergic Photothermal/Photodynamics/Chemo Therapy

To combine localized drug release with multimodal therapy for malignant tumor, a composite hydrogel as an integrative drug delivery system was facilely prepared. The system contains spinach extract （SE）, reduced graphene oxide （rGO） and gold nanocages （AuNCs）. SE conduces to the formation of hydrogel, and also serves as a green material for improving the biocompatibility of hydrogel, and a natural pho- tosensitizer for killing tumor cells under laser radiation （fi60 nm）. AuNts show obvious photothermy and can enhance the generation of cytotoxic singlet oxygen （102）. The composite hydrogel shell on tumor cells exhibits several competitive advantages including enhanced antitumor effect by retaining the high con- centration of drugs around cancer cell, excellent PDT/FFr compatibility as well as high loading and controllable release of fluorouracil （5-FU） for synergetic multimodal treatment. The survival rate of HeLa cells incubated with 5-FU loaded hydrogel under NIR radiation for 10 min sharply decreases to 1.2%, in- dicating remarkably improved antitumor effects. These results demonstrate that the hydrogel is an excellent delivery carrier for localizable, NIR-responsive and combined PTT/PDT/Chemo synergetic antitumor.