Nanjing Tech University

About: Nanjing Tech University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Membrane. The organization has 21827 authors who have published 21794 publications receiving 364050 citations. The organization is also known as: Nangongda & Nánjīng Gōngyè Dàxúe.

Electrospun nanofiber substrates that enhance polar solvent separation from organic compounds in thin-film composites

Abstract: Organic solvent nanofiltration (OSN) with thin film composite (TFC) membranes containing a thin selective layer on top of a porous substrate is key to lowering the energy costs of high-speed chemical separations Conventional TFC membranes were often built on phase inversion induced asymmetrical substrates with high tortuosity that impedes rapid solvent transport Nanofibers as ultrapermeable substrates have enhanced water transport in forward osmosis, nanofiltration and other aqueous separations However, problems of solvent stability under harsh operating conditions prevent their exploitation in non-aqueous molecular separations Here we show that by combining a simple solution-phase cross-linking process and electrospinning, the instability of nanofibrous polyacrylonitrile (PAN) in industrially important polar solvents can be overcome and harnessed to benefit the purification of polar solvents containing low molecular weight solutes The low tortuosity of electrospun PAN nanofibrous substrates is key to uniform cross-linking, and hence they are more stable and mechanically stronger than cross-linked PAN asymmetrical substrates fabricated by the traditional approach of phase inversion The low resistance offered by cross-linked nanofibrous substrates increased solvent permeation without sacrificing selectivity, for example, to 995% rejection of negatively charged Sudan 4 (MW: 380 Da) dye with a methanol permeance of 987 L m−2 h−1 bar−1 and water permeance of 2240 L m−2 h−1 bar−1 The enhanced stability of TFC membranes in polar aprotic solvents such as dimethylsulfoxide highlights their potential application for molecular separations in pharmaceutical and chemical industries

Screening highly active perovskites for hydrogen-evolving reaction via unifying ionic electronegativity descriptor

Abstract: Facile and reliable screening of cost-effective, high-performance and scalable electrocatalysts is key for energy conversion technologies such as water splitting. ABO3-δ perovskites, with rich constitutions and structures, have never been designed via activity descriptors for critical hydrogen evolution reaction (HER). Here, we apply coordination rationales to introduce A-site ionic electronegativity (AIE) as an efficient unifying descriptor to predict the HER activities of 13 cobalt-based perovskites. Compared with A-site structural or thermodynamic parameter, AIE endows the HER activity with the best volcano trend. (Gd0.5La0.5)BaCo2O5.5+δ predicted from an AIE value of ~2.33 exceeds the state-of-the-art Pt/C catalyst in electrode activity and stability. X-ray absorption and computational studies reveal that the peak HER activities at a moderate AIE value of ~2.33 can be associated with the optimal electronic states of active B-sites via inductive effect in perovskite structure (~200 nm depth), including Co valence, Co-O bond covalency, band gap and O 2p-band position. Facile and reliable screening of efficient electrocatalysts is important for energy conversion technologies such as water splitting. Here, authors introduce A-site ionic electronegativity as a descriptor to understand the hydrogen-evolution activities of cobalt-based perovskites.