A polyaniline (PAN) prepared by chemical oxidation method was studied for Hg(II) removal from aqueous solutions. Batch adsorption results showed solution pH values had a major impact on mercury adsorption by this sorbent with optimal removal observed around pH 4-6. At both acidic and alkaline solutions beyond this optimal pH window, sorption capacity of PAN was substantially lowered, with the impact less pronounced at pH above 6. Among the water constituents tested, only chloride and humic acid had significant inhibition on mercury removal due to competitive complexation. In the range of 0.02-0.2 M, ionic strength had less impact on Hg(II) removal by PAN while further increase in background electrolyte concentration to 1.0 M substantially decreased mercury removal. An adsorption mechanism was proposed by analyzing the XPS spectra of the key elements (N(1s), Cl(2p) and Hg(4f)) on polyaniline surfaces and the change of its electrokinetic properties, both before and after Hg(II) adsorption. Specifically, at pH 5.5, it is likely that all the nitrogen-containing functional groups on the polymer matrix including imine, protonated imine and amine could be responsible for mercury adsorption, with imine having the highest affinity while the remaining two having similar strength to complex mercury.

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A highly ordered binderfree multi-layered hydrogenated TiO2-II phase nanowire array (ML-HTO) negative electrode for 2.4 V aqueous asymmetric supercapacitors with high active materials loading, high electrical and ionic conductivity is synthesized via a multi-step method.

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Nitride phosphors have drawn much interest because of their outstanding thermal and chemical stability and interesting photoluminescence properties. Currently, it remains a challenge to synthesize these phosphors through a convenient chemical route. Herein we propose a general and convenient strategy based on hydrothermal-ammonolysis reaction to successfully prepare zinc germanium nitride (ZnGeN 2 ) and Mn 2+ doped ZnGeN 2 phosphors. The crystal structure, composition, morphology, luminescence and reflectance spectra, quantum efficiency, and the temperature-dependent photoluminescence behavior were studied respectively. The phase formation and crystal structure of ZnGeN 2 were confirmed from powder X-ray diffraction and Rietveld refinement. EDX analysis confirmed the actual atomic ratios of Zn/Ge and N/Ge and suggested the presence of Ge vacancy defects in the ZnGeN 2 host, which is associated with its yellow emission at 595 nm with a FWHM of 143 nm under UV light excitation. For Mn 2+ doped ZnGeN 2 phosphor, it exhibits an intense red emission due to the 4 T 1g -6 A 1g transition of Mn 2+ ions. The unusual red emission of Mn 2+ at the tetrahedral Zn 2+ sites is attributed to the strong nephelauxetic effect and crystal field between Mn 2+ and the tetrahedrally coordinated N 3À . Moreover, the PL intensity of ZnGeN 2 :Mn 2+ phosphors can be enhanced by Mg 2+ ions partially substituting for Zn 2+ ions in a certain concentration range. The optimal Mn 2+ doping concentration in the ZnGeN 2 host is 0.4 mol%. The critical energy transfer distance of this phosphor is calculated to be about 27.99 Å and the concentration quenching mechanism is proved to be the dipole-dipole interaction. With increasing temperature, the luminescence of ZnGeN 2 :Mn 2+ phosphors gradually decreases and the FWHM of the emission band broadens from 54 nm to 75 nm. The corresponding activation energy E a was reckoned to be 0.395 eV. And the nonradiative transition probability increases with the increasing temperature, finally leading to the lifetime decrease with the increase of the temperature.

A novel mesoporous indium–porphyrin framework JLU-Liu7 with frl net has been successfully synthesized. It exhibits high performance for gas adsorption and light hydrocarbon separation.

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