Transition‐metal sulfides have gained considerable attention for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable Zn‐air batteries owing to their natural abundance, chemical stability, and efficient activity. Here, cobalt sulfide nanocrystalline supported on the 3D hierarchically flower‐like porous nanocarbon (mC‐CoSx‐50) electrocatalysts have been synthesized through a combination of metal‐organic complexation and porous silica templates for efficient bifunctional oxygen catalysis. With the high specific surface area, high nitrogen content and heteroatom doping, the as‐synthesized mC‐CoSx‐50 exhibits an excellent bifunctional oxygen catalytic performance. Remarkably, the rechargeable Zn‐air batteries assembled with the cobalt sulfide‐based hierarchically porous electrocatalysts reveal a high peak power density and excellent cycling stability in comparison with Pt/C+RuO2 owing to the synergistic effects between cobalt sulfide nanocrystallines and hierarchically porous carbon. We envision that this work not only offers high‐performance metal sulfide for future clean energy conversion but also provides a facial strategy for constructing hierarchically porous carbon‐supported catalyst.
This tutorial review summarizes the basic concepts, design strategies and potential applications of semi-transparent organic photovoltaics (STOPVs). Challenges and research directions toward the commercialization of STOPVs are also proposed.
Nanocomposite pour point depressants (PPDs) provide a new way to further improve the fluidity of waxy crude oil at low temperatures, which has important application values in pipeline transportation. In this work, the effect of ethylenevinyl acetate (EVA) doped with magnetic spherical nanoparticles of Fe 3 O 4 (30 nm) on the morphology of wax crystals and the flow behavior of Daqing crude oil was investigated by polarized optical microscopy and rheological testing. The results showed that, compared to the EVA PPD doped with spherical nano-SiO 2 (with the same size), the EVA (VA = 28%)/Fe 3 O 4 nanocomposite PPD caused Daqing crude oil to have a more compact and regular wax crystal structure and a weaker gel structure because of the synergistic effect of magnetic materials and heterogeneous nucleation. This study examines the mechanism of nanocomposite PPDs and provides a new perspective for the development of new nanohybrid PPDs.
In this work, semiinterpenetrating polymer network (semi-IPN), consisting of sulfonated poly (arylene ether sulfone) (SPAES) and crosslinked vinyl imidazole grafted polysulfone (VMPSU), is prepared and characterized. FTIR, EDS, and solubility test indicate the successful preparation of amphoteric membranes. The semi-IPN amphoteric membranes exhibit better stability than pure SPAES membrane, as demonstrated by thermogravimetric analysis and ex situ immersion testing results. More importantly, it is shown that the amphoteric membrane can effectively hinder vanadium ion crossover through the membrane, which is attributed to the semi-IPN structure and Donnan exclusion. As expected, the amphoteric membrane containing 20% VMPSU exhibits the highest proton selectivity (6.86 × 10 4 S min cm −3), comparing to pristine SPAES (1.90 × 10 4 S min cm −3) as well as Nafion117 (1.31 × 10 4 S min cm −3).
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