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Nitrobenzene, a toxic nitroaromatic, a feedstock compound to the production of many commercially relevant chemicals were photoelectrocatalytically reduced into aniline on a photoelectrode comprised by a bismuth-doped CuGaS 2 nanocrystallyne thin films on molybdenum. The activity of the photoelectrodes were compared to the reaction performed on undoped-CuGaS 2 films, and they were carried out under illumination with an applied bias potential at 0.9 V. Aniline was highly selectively obtained with 83% of conversion for reaction times of 100 min when using Bi-doped CuGaS 2 , representing higher conversion of nitrobenzene and yield to aniline than the undoped photoelectrode. The catalytic performance of the doped films remained stable for a set of 5 consecutive experiments. These results indicate Bi-doped CuGaS 2 as a promising material to be applied in the photoelectrocatalytic reduction of nitrobenzene into aniline through the direct pathway mechanism, using solar light illumination., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A new epoxy/polyacrylate-modified oilwell cement slurry was synthesized. The features of the new slurry were evaluated in relation to a standard cement slurry (w/c=0.5). The characterization of the slurries was performed by Raman, XRD, TG/DTG and solid-state diffuse reflectance spectroscopy. The main morphological features of the new slurry were preserved, even after long-term contact with HCl in aqueous solution. The hydration of the slurries was studied by heat-conduction microcalorimetry. The exothermic microcalorimetric outputs were well fitted to a three-parameter kinetic model. The analysis of both thermodynamic and kinetic results from microcalorimetry have pointed out that diffusional growth from non-stoichiometric mixtures is the main mechanistic feature of the hydration of the cement slurries. The results of this study underline the excellent features of the new epoxy/superplasticizer-modified cement slurry for using in severe acidic environments of oilwells., (Copyright © 2012 Elsevier Inc. All rights reserved.)