ABSTRACT
The design and development of high-performance, low-cost catalysts with long-term durability are crucial for hydrogen generation from water electrolysis. Interfacial engineering is an appealing strategy to boost the catalytic performance of electrode materials toward hydrogen evolution reaction (HER). Herein, we report a simple phosphidation followed by sulfidation treatment to construct heterogeneous cobalt phosphide-cobalt sulfide nanowire arrays on carbon cloth (CoP/CoS2/CC). When evaluated as catalysts toward the HER, the resultant CoP/CoS2/CC exhibits efficient pH-universal hydrogen production due to the heterostructure, synergistic contribution of CoP and CoS2, and conductive substrate. To attain a current density of 10 mA cm-2, overpotentials of only 111.2, 58.1, and 182.9 mV for CoP/CoS2/CC are required under alkaline, acidic, and neutral conditions, respectively. In particular, the as-prepared CoP/CoS2/CC shows markedly improved HER electroactivity in 1.0 M KOH, even outperforming commercial Pt-C/CC at a current density of >50 mA cm-2. In addition, the self-assembled CoP/CoS2||NiFe layered double hydroxide electrolyzer demonstrates efficient catalytic performance and long-time stability, excelling the benchmark Pt-C||IrO2. These findings indicate an effective pathway for the fabrication of high-performance heterogeneous electrocatalysts for hydrogen production in the future.
ABSTRACT
Fresh mulberry leaf vegetable is nutritive and becoming popular. However, available preservation technologies are deficient. In present work, the effects of two kinds of modified atmosphere packaging on postharvest quality of fresh mulberry leaf vegetable stored at 4 °C were evaluated. The respiration rate of samples in the modified polyethylene packages (MP20) was 12.88-22.65% lower than that in normal polyethylene packaging (CK). The content of total soluble solids, soluble protein, and total polyphenol in MP20 was less changed than that in CK, and the vitamin C retention was higher as well. Moreover, the lignin content in MP20 was lower than that in CK during storage (19.79% vs 13.38% at day 8), and that was significantly positively related to the polyphenol oxidase and peroxidase activities inhibition. Taken together, a packaging with moderate gas permeability (MP20) is suitable for nutrition maintenance and lignification inhibition of fresh mulberry leaf vegetable during cold storage.
