Electrocatalytic properties of AMIM-Br-MWCNTs originate from a synergistic effect of covalent bond structure, in which AMIM-Br obtains the strongest proton adsorption ability, while the MWCNTs facilitates the electron-transfer process.

No abstract

New catalyst for hydrogen generation by water electrolysis in aqueous acid is made by mixing N,N‐bis(4‐ (methoxycarbonyl)benzyl)‐N‐methyl‐d‐glucaminium bromide (MBMG−Br) and trichloroferrate (III) to form the iron containing ionic liquid (IL), MBMG‐FeCl3Br. This IL is mixed with carbon nanotubes (CNTs) and sodium hypophosphite (NaH2PO2) and then heated to 300 oC in an inert atmosphere to give the final catalyst, a CNT‐supported iron phosphide (FePMBMG/CNT), which exhibits catalytic activity toward hydrogen evolution reaction in 0.5 M aqueous sulfuric acid electrolyte with a low onset overpotential of 70 mV, a Tafel slope of 75.9 mV dec−1, 95% Faradaic efficiency (FE) and current densities of 10 and 20 mA cm−2, at overpotentials of 155 and 195 mV respectively, for a catalyst loading of 100 μg on 0.2 cm2 of glassy carbon electrode in which the IL to CNTs amount ratio is 1:1.

A novel Pb(II) ion-imprinted chelating nanofibers (nIIP), synthesized by combining electrospinning with surface ion imprinting technique, was reported in this study. nIIP was characterized with Fourier transmission infrared spectrometry and scanning electron microscopy, respectively. The performance of nIIP for Pb(II) sorption was conducted through a batch adsorption experiments. Experimental data showed that adsorption capacity of nIIP was much higher than that of non-ion imprinted chelating acrylic microfibers (mNIP) derived from commercial available acrylic microfibers, and adsorption behaviors agreed well with pseudo-second-order kinetic and Langmuir isotherm model. The values of Gibbs free energy change derived from experimental data suggested that the adsorption Pb(II) on nIIP is spontaneous and favorable at high temperature. In addition, nIIP had the highest selectivity among three tested fibrous adsorbents for Pb(II) from binary metal solution, the selectivity coefficients for Pb(II) from binary metal solution of Pb(II)/Cu(II), Pb(II)/Ni(II), and Pb(II)/ Cd(II) onto nIIP were 47, 101, and 162, respectively. Besides, a forty adsorption/desorption cycles revealed that nIIP was a promising recyclable adsorbent. In conclusion, the novel nIIP is a highly effective adsorbent for enrichment and separation of Pb(II) in the presence of competitive ions in aqueous solution, and it is potential to be applied for recovering metals from heavy metal polluted industrial wastewater such as Pb(II)/Cd(II), Pb(II)/Ni(II), and Pb(II)/Cu(II) polluted wastewater.