Stevensonbates5633

9 mg g-1 at 25 °C. During adsorption kinetics, a rapid dye removal was observed which followed pseudo-first- as well as pseudo-second-order models, which suggested that MB dye molecules were adsorbed onto MCA@SiO2 via both ion exchange as well as the chemisorption process. TRULI purchase The endothermic and spontaneous nature of the adsorption of MB onto MCA@SiO2 was established by thermodynamics studies. Mechanism of dye diffusion was collectively governed by intraparticle diffusion and film diffusion processes. Furthermore, MB was also selectively adsorbed from its mixture with an anionic dye, that is, methyl orange. Column adsorption studies showed that approximately 500 mL of MB having 50 mg L-1 concentration can be treated with 0.5 g L-1 of MCA@SiO2. Furthermore, MCA@SiO2 was repeatedly used for 20 cycles of adsorption-desorption of MB. Therefore, MCA@SiO2 can be effectively utilized in cationic dye-contaminated wastewater remediation applications. Copyright © 2020 American Chemical Society.An inexpensive, simple, and high-activity catalyst preparation method has been introduced in this work. Pt and RuO x catalysts were fabricated by soaking inexpensive graphite electrodes (pencil-lead graphite rod PGR) in catalyst precursor solutions and using a simple flame-annealing method, which results in lower amount of Pt and RuO x catalyst layers. From X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure analysis, it has been found that platinum and ruthenium were deposited as zero-valence metal (Pt) and oxide (RuO x ), respectively. Catalytic activities of Pt/PGR and RuO x /PGR for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were evaluated using neutral 1 M Na2SO4 aqueous electrolyte, respectively. Although HER and OER currents using PGR without catalysts were -16 mA cm-2 (at -1.5 V vs Ag/AgCl) and +20 mA cm-2 (at +2.0 V vs Ag/AgCl), they were improved to -110 and +80 mA cm-2 with catalysts (Pt and RuO x ), respectively. Such an inexpensive and rapid catalyst electrode preparation method on PGR using flame-annealing is a very significant method in the initial catalyst activity evaluation requiring a large amount of trial and error. Copyright © 2020 American Chemical Society.A scan-mode low-temperature ( less then 40 °C) atmospheric-pressure helium (He) dielectric-barrier discharge jet (DBDjet) is applied to treat nickel oxide (NiO) thin films for p-i-n perovskite solar cells (PSCs). Reactive plasma species help reduce the trap density, improve the transmittance and wettability, and deepen the valence band maximum (VBM) level. A NiO surface with the lower trap density surface of NiO allows better interfacial contact with the MAPbI3 layer and increases the carrier extraction capability. MAPbI3 can better crystallize on a more hydrophilic NiO surface, thereby suppressing charge recombination from the grain boundary and the interface. Further, the deeper VBM allows better band alignment and reduces the probability of nonradiative recombination. NiO treatment using He DBDjet with a scan rate of 0.3 cm/s can improve PSC efficiency from 13.63 to 14.88%. Copyright © 2020 American Chemical Society.The influence of hammer mill screen size (4.5 and 8.5 mm) and enzyme addition (control and 500 ppm) on olive fruit cell wall breakdown and its consequences in terms of oil recovery and the phenolic content of olive oil was studied at the laboratory scale for "Arbequina" and "Koroneiki" at two different maturities. Water recovery and water-soluble carbohydrates in olive paste after malaxation were measured as an indicator of cell wall breakdown. Smaller screen size and enzymes increase oil recovery for Arbequina with a maturity index of 1.6 (6.3-6.6%); and for Koroneiki at a maturity index of 0.2 (15.0-38%) and 2.6 (1.3-4.3%). For both cultivars, the increase in oil recovery is larger in green fruits compared to more ripe fruit. Water recovery and water-soluble carbohydrates increase with small screen size and the enzyme treatments, even when no increment in oil recovery is observed. The water recovery range was 143-239% for Arbequina and 150-262% for Koroneiki; water-soluble carbohydrate range was 1.8-12.7 g/kg for Arbequina and 0.5-5.4 g/kg for Koroneiki. In general, smaller hammer mill screen size and enzymes increase total phenols in the oil, with a larger difference between control and treatment for green fruit than for the ripe fruit. For Arbequina, increases in total phenol content were in the range of 45-60 and 5-20% at maturity index 1.6 and 3.3, respectively. For Koroneiki, the increases were in the range of 31-121 and 7-9% at maturity index 0.2 and 2.6, respectively. Application of cell wall-degrading enzymes improves the cell wall breakdown caused by hammer mill, leading to higher oil recovery and total phenol content. The magnitude of the effect depends on the cultivar and olive fruit maturity. Copyright © 2020 American Chemical Society.Capping agents play an important role in the synthesis of silver nanostructures in polyol solvents. In this work, we demonstrate that using a small amount of tannic acid (TA), a reducing capping agent, in addition to poly(vinylpyrrolidone) (PVP), a protective capping agent, can lead to the production of monodisperse spherical silver nanoparticles (Ag NPs) that are stable with respect to particle aggregation for at least 100 days and have particle sizes ranging from 16 to 28 nm depending on the TA concentration. We hypothesize that the complexation between PVP and TA can lead to the formation of a stable particle coating and a fast Ag+ reduction rate at a relatively high TA concentration. Both effects can benefit the formation of small spherical Ag NPs with narrow size distribution. Copyright © 2020 American Chemical Society.To enrich an acid-tolerant methanogenic culture used as bioaugmented seed under acidic conditions, we operated four semicontinuous digesters under various conditions of pH decline for producing methane at pH 5.0. 16S rRNA amplification was performed to unravel the association between declining pH and microbiome succession. The findings demonstrated that a gradual decrease of pH, at a step size of 0.5, and a prolonged run time at each pH could achieve a suitable microbial culture, in which acetoclastic Methanothrix and hydrogenotrophic Methanolinea represented the dominant methanogens. In contrast, a sharp decline in pH could result in heavy loss of the acetoclastic methanogen Methanothrix, leading to a cessation of methane production. Hydrogenotrophic methanogens exhibited high acid tolerance, and Methanospirillum could thrive despite a sudden low-pH shock. Although Methanolinea required a longer time to enrich, it played a substantial role in methane production under an acidic environment. Copyright © 2020 American Chemical Society.