Highly Active Co3O4-Based Catalysts for Total Oxidation of Light C1–C3 Alkanes Prepared by a Simple Soft Chemistry Method: Effect of the Heat-Treatment Temperature and Mixture of Alkanes

In the present work, a simple soft chemistry method was employed to prepare cobalt mixed oxide (Co3O4) materials, which have shown remarkably high activity in the heterogeneously catalyzed total oxidation of low reactive VOCs such as the light alkanes propane, ethane, and methane. The optimal heat-treatment temperature of the catalysts was shown to depend on the reactivity of the alkane studied. The catalytic activity of the Co3O4 catalysts was found to be as high as that of the most effective catalysts based on noble metals. The physicochemical properties, from either the bulk (using XRD, TPR, TPD-O2, and TEM) or the surface (using XPS), of the catalysts were investigated to correlate the properties with the catalytic performance in the total oxidation of VOCs. The presence of S1 low-coordinated oxygen species at the near surface of the Co3O4-based catalysts appeared to be linked with the higher reducibility of the catalysts and, consequently, with the higher catalytic activity, not only per mass of catalyst but also per surface area (enhanced areal rate). The co-presence of propane and methane in the feed at low reaction temperatures did not negatively affect the propane reactivity. However, the co-presence of propane and methane in the feed at higher reaction temperatures negatively affected the methane reactivity.

Photodegradation of Biohazardous Dye Brilliant Blue R Using Organometallic Silver Nanoparticles Synthesized through a Green Chemistry Method

Nowadays, nanostructures having tremendous chemical and physical properties are gaining attention in the biomedical industry. However, when they are prepared through classical methods (physical and chemical), they are often non-biocompatible and toxic. Considering the mentioned factors, in this research, organometallic silver nanostructures (OMAgNs) have been prepared by the green chemistry method using the acetone, methanol, and methanol-hexane-based extracts of the medicinally important plant Cichorium intybus. Secondary metabolites from C. intybus can be used as an alternative to synthetic reagents at an industrial scale to manufacture biosafe and economical nanostructures with enhanced physicochemical parameters. Prepared nanostructures were characterized using SEM, XRD, FTIR, TGA, UV, and zeta potential measurement. SEM analysis revealed different shapes of OMAgNs, prepared with various extracts. XRD analysis showed the crystallinity of the nanostructures. FTIR spectroscopy helped to identify groups of compounds present in the extracts and used for the OMAgNs synthesis. Out of the three tested OMAgNs, those prepared with methanol extract were selected due to the highest obtained yield and stability (highest negative zeta potential) and were tested as a cost-efficient and active agent to photodegrade organic pollutant, Brilliant Blue R, using energy from sunlight. A decrease in UV-VIS absorbance confirmed the rapid degradation of the dye.

Synthesizing high value-added composite photocatalyst using waste capacitors combined with PANI by mechanical chemistry method

The main components of waste capacitors are BaTiO3, Ag, Pd, Sn, Ni, Nb, and Pb, which are valuable for recycling. At present the acid leaching is applied to separate metals...

Nanoboxes with a porous MnO core and amorphous TiO2 shell as a mediator for lithium–sulfur batteries

Nanoboxes with a porous MnO core and amorphous TiO2 shell have been synthesized via a wet-chemistry method for the first time.

A highly luminescent and stable copper halide ionic hybrid structure with anionic CuBr2(tpp)2 module

Here, we report a novel copper bromide ionic cluster (bz-ted)CuBr2(tpp)2·H2O (1, tpp = triphenylphosphine, bz-ted = 1-benzyl-1,4-diazabicyclo[2.2.2]octan-1-ium) by a facile wet chemistry method. The inorganic module of the compound is...