Cuiping Mao

Facile Synthesis of Novel Networked Ultralong Cobalt Sulfide Nanotubes and Its Application in Supercapacitors

Ultralong cobalt sulfide (CoS(1.097)) nanotube networks are synthesized by a simple one-step solvothermal method without any surfactant or template. A possible formation mechanism for the growth processes is proposed. Owing to the hollow structure and large specific area, the novel CoS(1.097) materials present outstanding electrochemical properties. Electrochemical measurements for supercapacitors show that the as-prepared ultralong CoS(1.097) nanotube networks exhibit high specific capacity, good capacity retention, and excellent Coulombic efficiency.

Fabrication of CeO2 nanoparticle-modified silk for UV protection and antibacterial applications.

To endow silk with UV-shielding ability and antibacterial activity, CeO2 nanoparticles were immobilized on silk surface via a dip-coating approach without changing silk structure. Surface density of the nanoparticles could be easily adjusted by controlling the number of dip-coating cycle. Enhanced thermal stability of the modified silk is exhibited in thermogravimetric analysis (TGA) and derivative thermogravimetric analysis (DTG). The excellent UV-protection ability and antibacterial property of the CeO2 nanoparticle-coated silk are demonstrated in UV-vis diffuse reflectance spectroscopy and colony-forming capability test, respectively. Based on the data, it can be concluded that CeO2 nanoparticles could be used as a very promising coating material to modify silk for UV-protection and antibacterial applications.

Highly conductive graphene-coated silk fabricated via a repeated coating-reduction approach

A repeated coating-reduction approach was developed to directly immobilize graphene nanosheets on silk for high conductivity. The as-prepared highly conductive graphene-coated silk fabrics (1.5 kΩ sq−1) and fibers (3595 S m−1) are promising as the functional supporting matrix and conducting fabrics/wires in future wearable electronics.

Aspergillus flavus Conidia-derived Carbon/Sulfur Composite as a Cathode Material for High Performance Lithium–Sulfur Battery

A novel approach was developed to prepare porous carbon materials with an extremely high surface area of 2459.6 m2g−1 by using Aspergillus flavus conidia as precursors. The porous carbon serves as a superior cathode material to anchor sulfur due to its uniform and tortuous morphology, enabling high capacity and good cycle lifetime in lithium sulfur-batteries. Under a current rate of 0.2 C, the carbon-sulfur composites with 56.7 wt% sulfur loading deliver an initial capacity of 1625 mAh g−1, which is almost equal to the theoretical capacity of sulfur. The good performance may be ascribed to excellent electronic networks constructed by the high-surface-area carbon species. Moreover, the semi-closed architecture of derived carbons can effectively retard the polysulfides dissolution during charge/discharge, resulting in a capacity of 940 mAh g−1 after 120 charge/discharge cycles.

A selenium-confined porous carbon cathode from silk cocoons for Li–Se battery applications

A composite of selenium (Se) and a rich porous carbon material (PCM) with mesopores from silk cocoons is explored as a cathode for lithium–selenium (Li–Se) batteries for the first time. Elemental selenium is homogeneously dispersed inside the mesopores of the PCM by a melt-diffusion method based on several analyses. The synthetic PCM/Se composite can effectively suppress the dissolution of the active material and maintain mechanical stability. In the case of Li–Se batteries, it delivers a reversible capacity of more than 230 mA h g−1 after 510 cycles at 2C. The remarkable electrochemical performance may benefit from the favorable conductivity and the porous structure of the carbon material as the host matrix.

Porous carbon derived from Sunflower as a host matrix for ultra-stable lithium–selenium battery

A novel porous carbon material using the spongy tissue of sunflower as raw material is reported for the first time. The obtained porous carbon has an extremely high surface area of 2493.0m2g-1, which is beneficial to focus on encapsulating selenium in it and have an inhibiting effect about diffusion of polyselenides over the charge/discharge processes used as the host matrix for Li-Se battery. The porous carbon/Se composite electrode with 63wt% selenium delivers a high specific capacitance of 319mAhg-1 of the initial capacity, and maintains 290mAhg-1, representing an extremely high capacity retention of 90.9% after 840 cycles with the rate of 1C.

Ferric ion-assisted in situ synthesis of silver nanoplates on polydopamine-coated silk.

In the present study, a ferric ion (Fe(3+))-assisted in situ synthesis approach was developed to grow silver (Ag) nanoplates on the polydopamine (PDA)-coated silk without the use of additional reductants. The essential role of Fe(3+) in the formation of Ag nanoplates is revealed by comparing the morphologies of Ag nanostructures prepared on the silk-coated PDA film with/without Fe(3+) doping. Scanning electron micrographs show that high-density Ag nanoplates could be synthesized in the reaction system containing 50μg/mL FeCl3 and 50mM AgNO3. The size of the Ag nanoplate could be tuned by adjusting the reaction duration. Based on the data, a mechanism involving the Fe(3+)-selected growth of Ag atoms along the certain crystal faces was proposed to explain the fabrication process. Transmission electron microscopy and X-ray diffractometry indicate that the Ag nanoplates possess good crystalline structures. Raman spectra demonstrate that the nanoplates could strongly enhance the Raman scattering of the PDA molecules. The Ag nanoplate-coated silk could be utilized as a flexible substrate for the development of surface-enhanced Raman scattering biosensors.

Bio-inspired synthesis of carbon hollow microspheres from Aspergillus flavus conidia for lithium-ion batteries

A conidium-templated approach is developed to prepare carbon hollow microspheres, which demonstrate great potential to be applied as anode materials in lithium-ion batteries. This work may provide a novel method to fabricate conidium-derived carbon materials for energy systems.