Linear Free Energy Relationships near Isokinetic Temperature. Oxidation of Organic Sulfides with Nicotinium Dichromate

The nicotinium dichromate (NDC) oxidation of methyl phenyl sulfide (MeSPh) in acetonitrile, brought about by p-toluenesulfonic acid (TsOH), is first order in NDC and TsOH, and is zero order with respect to MeSPh in the concentration range investigated. The NDC oxidation of 14 para-, meta- and ortho-substituted phenyl methyl sulfides at 293-318 K complies with the isokinetic relationship but not to any of the linear free energy relationships; the isokinetic temperature lies within the experimental temperature range

Photoproduction of iodine with nanoparticulate semiconductors and insulators

The crystal structures of different forms of TiO2 and those of BaTiO3, ZnO, SnO2, WO3, CuO, Fe2O3, Fe3O4, ZrO2 and Al2O3 nanoparticles have been deduced by powder X-ray diffraction. Their optical edges have been obtained by UV-visible diffuse reflectance spectra. The photocatalytic activities of these oxides and also those of SiO2 and SiO2 porous to oxidize iodide ion have been determined and compared. The relationships between the photocatalytic activities of the studied oxides and the illumination time, wavelength of illumination, concentration of iodide ion, airflow rate, photon flux, pH, etc., have been obtained. Use of acetonitrile as medium favors the photogeneration of iodine

Nonquenching of Charge Carriers by Fe₃O₄ Core in Fe₃O₄/ZnO Nanosheet Photocatalyst

Fe₃O₄-implanted ZnO and pristine ZnO nanosheets have been synthesized hydrothermally. High-resolution scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, elemental mapping, selected area electron diffractometry, powder X-ray diffractometry, Raman spectroscopy, vibrating sample magnetometry, solid state impedance spectroscopy, UV–visible diffuse reflectance spectroscopy, and photoluminescence spectroscopy show implantation of Fe₃O₄ in ZnO nanosheets. Fe₃O₄ core with ZnO shell is of type I core/shell heterostructure which is to quench charge carriers and suppress photocatalysis. But the photocatalytic activity is not suppressed on implantation of Fe₃O₄ in ZnO nanosheets, and time controlled single photon counting lifetime spectroscopy shows that the photogenerated charge carriers are not quenched by the Fe₃O₄ core in the ZnO nanosheets. The composite nanosheets are photostable, reusable, and magnetically recoverable, revealing potential application in mineralization of organic pollutants