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Abstract: A novel electrochemical sensor for chlorophenols was fabricated by using the Pd-graphene nanocomposite and ions liquid. The Pd-graphene nanocomposite was prepared via a sonoelectrochemical route, and the possible formation mechanism was proposed. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Raman spectrum were used for the characterization of structure and morphology of the nanocomposite. The experimental results showed that Pd nanospheres comprised of small Pd nanoparticles were uniformly attached on graphene sheets. The electrocatalytic properties were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which indicated that the Pd-graphene nanocomposite had high activity for chlorophenol oxidation. Herein, 2-chlorophenol was selected as the model molecules. The results showed that graphene played an important role in the fabrication of the chlorophenols sensor. The nanocomposite with large electrochemical active surface led to the excellent electrocatalytic activity, and ionic liquid further enhanced the catalytic activity of Pd-graphene for chlorophenols. [Copyright &y& Elsevier]

Two dimensional heteroatoms-doped graphitic carbon electrode materials could exhibit better capacitive properties than undoped carbon materials. However, since the configuration and the content of the heteroatoms as well as their porous structure are difficult to control, the improvement of their energy storage performance is limited. Here, we report a hierarchically porous boron-doped graphitic carbon nitride nanosheet electrode material with high electrochemical energy storage performances, including high specific capacitances at a fast, carbon-like speed (620.0 F g −1 at 0.1 A g −1 and 312.0 F g −1 at 20 A g −1 ), a high energy density of 86.1 Wh kg −1 and a stable cycling durability with no capacitance declination after 2500 charge-discharge cycles. The improvement stems from the hierarchically porous structure with dominant pore sizes among 1–3 nm, increased pyrrolic nitrogen (11.12 at%) and boron (8.21 at%) active sites due to the addition of ionic liquid. This study has provided a new idea on improving the doping level and porous structure of the electrode material by using ionic liquid as both the heteroatoms source and pore template. [ABSTRACT FROM AUTHOR]

A series of stable quasi-solid-state dye-sensitized solar cells (QS-DSSCs) are prepared by the 12-hydroxystearicacid as low molecular mass organogelator (LMOG) to gelate the ionic liquid with different alkyl chain lengths (3, 4, and 7). The influence of alkyl chain length of imidazolium cations (Im + ) on the kinetic processes of electron transport and recombination are investigated by Electrochemical impedance spectroscopy (EIS) and intensity-modulated photocurrent spectroscopy/intensity-modulated photovoltage spectroscopy (IMPS/IMVS). It is found that the ionic gel electrolytes (IGEs) with different alkyl chain lengths of Im + can influence the competitive adsorption effects of imidazolium cations (Im + ) and Li + , and further affect the charge diffusion, the electron recombination/transport processes, the shift of TiO 2 conduction band edge and surface states distribution. The IGE with longer alkyl chain length of Im + can prolong the electron recombination lifetime, promote the incidental photon-to-electron conversion efficiency (IPCE) and the short circuit photocurrent density ( J sc ). An excellent QS-DSSC based on the IGE with the longer alkyl chain of Im + gives the highest photoelectric conversion efficiency. Moreover, all the QS-DSSCs based on IGEs exhibit excellent durability without losing their photovoltaic performances during the accelerated thermal and light–soaking test. These results are very important to the researches on the electrochemical mechanism and application of QS-DSSCs based on IGEs. [ABSTRACT FROM AUTHOR]