RESUMEN
A novel high-nuclearity silver sulfide nanocluster [Ag50S7(SC6H4F)36(dppp)6]·4DMI, (hereafter abbreviated as 1â 4DMI) was synthesised. Solvent-free crystals of 1 displayed a completely reversible narrowing and broadening of the optical band gap that was accompanied by visual thermochromism and piezochromism changeovers, when stimulated by varying temperatures between 113 and 413 K or by changing the pressure from 1 atm to 7.5 GPa.
RESUMEN
In this study, we, for the first time, demonstrate a general solid-phase pyrolysis method to synthesize hybrid transition metal nanocrystal-embedded graphitic carbon nitride nanosheets, namely M-CNNs, as a highly efficient oxygen electrocatalyst for rechargeable Zn-air batteries (ZABs). The ratios between metallic acetylacetonates and the g-C3N4 precursor can be controlled where Fe-CNNs-0.7, Ni-CNNs-0.7 and Co-NNs-0.7 composites have been optimized to exhibit superior ORR/OER bifunctional electrocatalytic activities. Specifically, Co-CNNs-0.7 exhibited not only a comparable half-wave potential (0.803 V vs. RHE) to that of the commercial Pt/C catalyst (0.832 V) with a larger current density for the ORR but also a lower overpotential (440 mV) toward the OER compared with the commercial IrO2 catalyst (460 mV), revealing impressive application in rechargeable ZABs. As a result, ZABs using Co-CNNs-0.7 as the cathode exhibited an excellent peak power density of 85.3 mW cm-2 with a specific capacity of 675.7 mA h g-1 and remarkable cycling stability of 1000 cycles, outperforming the commercially available Pt/C + IrO2 catalysts. This study highlights the synergy from heterointerfaces in oxygen electrocatalysis, thus providing a promising approach for advanced metal-air cathode materials.
RESUMEN
The low solubility of wheat gluten limits its accessibility. This work aimed to study the impact of ultrasonic pretreatments on the gelation of wheat gluten. The pretreatments included ultrasound combined with alkali, urea, Na2SO3, with or without the addition of transglutaminase (TGase). The gel strength of wheat gluten was 287g/cm2 after treatment with Na2SO3/ultrasound/TGase. The free sulfhydryl and disulfide bond content was significantly affected by ultrasound treatment. After treatments including TGase crosslinking, the molecular weight of wheat gluten complexes became larger. The network formed by the wheat gluten was transformed into a dense and homogenous structure after the pretreatment with Na2SO3/ultrasound/TGase. The content of random coil of wheat gluten increased. The gelation of wheat gluten could also be significantly enhanced by Na2SO3/ultrasound treatment followed by TGase treatment. Using physical and chemical pretreatments to allow TGase to enhance the gelation of wheat gluten may increase its uses as a food additive.
