In this work, we prepared a continuous nanostructured Pt-mirror film with metallic lustre and good adhesion to the F-doped tin oxide conducting glass (FTO) substrate through a simple in situ growth method, which retains a good catalytic activity and more importantly, exhibits significant light reflection for light-harvesting. The dye-sensitized solar cells (DSCs) fabricated with Pt-M CE exhibited superior photovoltaic performance compared with the conventional Pt CE. The enhancements of the short-circuit current density and energy conversion efficiency are 15.3% and 18.5%, respectively. Such significant enhancement of the short-circuit current density was found to be related to the excellent light reflection and high catalytic activity of the Pt-M CE. This has been proved by ultraviolet and visible reflection spectra (UV/Vis), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).
24 January 2017 in Journal of Materials Chemistry A
The effect of imidazolium-based ionic liquid on the electroreduction of CO2 to CO over a Ag electrode in acetonitrile catholyte was investigated. The voltage–current profiles clearly indicate that the electroreduction of CO2 is sensitive to the alkyl chain length at the N1-position in imidazolium cation (MIM+). Density functional theory computation suggests that the onset potential of CO2 reduction is related to the association degree between MIM+ and CO2•– species. More importantly, preparative scale electrolysis shows that the selectivity and output rate for the target product CO are also significantly affected by MIM+. With the elongation of the alkyl group in MIM+ from ethyl to octyl, the Faradaic efficiency for CO remarkably increases from 87 ± 4 % to 97 ± 2 % and then remains almost unchanged. However, the curve of the current density with respect to the chain length of alkyl group shows a convex style. These results indicate the dependence of CO2 reduction efficiency on the MIM+ adsorbed on the Ag electrode surface.
Due to CO2 mass transfer limitation as well as the competition of hydrogen evolution reaction in electroreduction of CO2 in the aqueous electrolyte, Zn-based electrodes normally exhibit unsatisfying selectivity for CO production, especially at high potentials. In this work, we introduced a zinc myristate (Zn [CH3(CH2)12COO]2) hydrophobic layer on the surface of zinc foam electrode by an electrodeposition method. The obtained hydrophobic zinc foam electrode showed a high Faradaic efficiency (FE) of 91.8% for CO at −1.9 V (vs. saturated calomel electrode, SCE), which was a remarkable improvement over zinc foam (FECO = 81.87%) at the same potentials. The high roughness of the hydrophobic layer has greatly increased the active surface area and CO2 mass transfer performance by providing abundant gas-liquid-solid contacting area. This work shows adding a hydrophobic layer on the surface of the catalyst is an effective way to improve the electrochemical CO2 reduction performance.
To introduce the randomness of a physical process to students, a chaotic pendulum experiment was opened in East China University of Science and Technology (ECUST) on the undergraduate level in the physics department. It was shown chaotic motion could be initiated through adjusting the operation of a chaotic pendulum. By using the data of the angular displacements of chaotic motion, random binary numerical arrays can be generated. To check the randomness of generated numerical arrays, the NIST Special Publication 800-20 method was adopted. As a result, it was found that all the random arrays which were generated by the chaotic motion could pass the validity criteria and some of them were even better than the quality of pseudo-random numbers generated by a computer. Through the experiments, it is demonstrated that chaotic pendulum can be used as an efficient mechanical facility in generating random numbers, and can be applied in teaching random motion to the students.