Fanglin Du

Facile surfactant-assisted synthesis of CTAB-incorporated MoS2 ultrathin nanosheets for efficient hydrogen evolution

Molybdenum disulfide (MoS2) has emerged as a promising electrocatalyst for catalyzing protons to hydrogen via the so-called hydrogen evolution reaction (HER). In order to enhance the HER activity, CTAB (cetyltrimethyl ammonium bromide)-incorporated MoS2 ultrathin nanosheets with high specific surface area and more catalytic active sites have been successfully synthesized via a facile surfactant-assisted hydrothermal approach. Adding CTAB to the hydrothermal process can effectively regulate both structural and electronic benefits by controllable disorder engineering and simultaneous CTAB incorporation in MoS2 catalysts, leading to a higher specific surface area, more catalytic active sites and better electrical conductivity for improving HER activity. The optimized CTAB-incorporated MoS2 ultrathin nanosheets exhibit excellent activity for HER with a small onset potential of 88 mV, a low Tafel slope of 55 mV dec−1, and relatively good stability.

Template synthesis of NiO ultrathin nanosheets using polystyrene nanospheres and their electrochromic properties

Ultrathin nickel oxide (NiO) nanosheets with a thickness of ∼10 nm were synthesized by a template method. NiO film was prepared by spin-coating polystyrene@Ni2CO3(OH)2 nanostructures on indium tin oxide (ITO) coated glass and a calcination process. Electrochromic properties of NiO thin film were investigated in an aqueous alkaline electrolyte (1.0 mol L−1 KOH) by means of transmittance and cyclic voltammetry (CV) measurement. The NiO film annealed at 300 °C exhibits noticeable electrochromism with a transmittance modulation of 40.1%, fast coloration and bleaching responses (5.4 and 3.6 s) and high coloration efficiency (43.5 cm2 C−1).

Polypyrrole-assisted synthesis of roselike MoS2/nitrogen-containing carbon/graphene hybrids and their robust lithium storage performances

Roselike MoS2/nitrogen-containing carbon/graphene (MoS2/NC/G) hybrids were successfully synthesized via a facile polypyrrole (PPy)-assisted hydrothermal approach in combination with high-temperature calcination. The obtained MoS2/NC/G hybrids manifest roselike MoS2 composed of nanosheets coupled uniformly on NC/G nanosheets due to the strong interactions between MoS2 and the abundant nitrogen-containing functional groups of NC. When used as anode materials for lithium ion batteries, the MoS2/NC/G hybrids exhibit enhanced electrochemical energy storage performances compared to the bare MoS2 nanosheets, including high specific capacity (1570.6 mA h g−1 at 0.1 A g−1), excellent rate capability (704.8 mA h g−1 at 5 A g−1) and good cycling stability (96.4% capacity retention after 100 cycles at 0.2 A g−1). The enhanced lithium storage properties of the MoS2/NC/G hybrids can be ascribed to the boosted electronic conductivity arising from the novel hybrid nanostructures of MoS2/NC/G.

Electrodeposition of Prussian blue films on Ni3Si2O5(OH)4 hollow nanospheres and their enhanced electrochromic properties

Porous Prussian blue (PB) films were successfully electrodeposited on Ni3Si2O5(OH)4 hollow nanosphere coated indium tin oxide (ITO) glass. Ni3Si2O5(OH)4 hollow nanospheres hydrothermally synthesized using SiO2 nanospheres as templates play a key role in the formation of porous PB films. The as-prepared PB films exhibit larger transmittance change, faster switching response and higher coloration efficiency than those of dense PB films directly electrodeposited on ITO glass. The enhanced electrochromic properties are attributed to the large specific surface area and porosity of the PB films which bring a high diffusion rate and short diffusion path length of ions.

The reaction mechanism for highly effective hydrodechlorination of p-chlorophenol over a Pd/CNTs catalyst

Carbon nanotubes (CNTs) supported Pd catalysts (1 wt% and 5 wt%) were prepared by a conventional impregnation method and tested in liquid-phase hydrodechlorination (HDC) of para-chlorophenol (p-CP) under mild conditions (313 K and atmospheric pressure) with H2. CNTs as a catalyst support offered better performance than activated carbon (AC). The conversion of p-CP reached 72% and 82% over 5 wt% Pd/AC and 5 wt% Pd/CNTs, respectively, within 30 min. When the content of Pd was reduced to 1 wt%, the conversion of p-CP over Pd/AC and Pd/CNTs was 55% and 83%, respectively. The mechanism of this phenomenon was studied through catalyst characterization (XRD, TEM, and BET). The abovementioned results indicated that the different activities of the catalysts over different supports mainly resulted from the porous structure of the supports and nanoparticle diameters of the active metal.