Henan Normal University

About: Henan Normal University is a education organization based out in Xinxiang, China. It is known for research contribution in the topics: Catalysis & Ionic liquid. The organization has 10863 authors who have published 11077 publications receiving 166773 citations.

Nanocage-Based N-Rich Metal-Organic Framework for Luminescence Sensing toward Fe3+ and Cu2+ Ions.

Abstract: Luminescent metal-organic frameworks (LMOFs) as sensors showing highly efficient detection toward toxic heavy-metal ions are in high demand for human health and environmental protection. A novel nanocage-based N-rich LMOF (LCU-103) has been constructed and characterized. It is a 2-fold interpenetrating structure built from N-rich {Zn6(dttz)4} nanocages extended by N-donor ligand Hdpa [H3dttz = 4,5-di(1H-tetrazol-5-yl)-2H-1,2,3-triazole; Hdpa = 4,4'-dipyridylamine]. Notably, LCU-103 contains abundant N functional sites anchoring on both the windows of nanocages and the inner channels of the framework that can interact with metal ions and then recognize them. As a result, it can serve as a luminescent sensing material for detecting trace amounts of Fe3+ and Cu2+ ions with low limits of detection (LODs) of 1.45 and 1.66 μM, respectively, through a luminescent quenching mechanism. Meanwhile, LCU-103 as a LMOF sensor exhibits several advantages such as high sensitivity, appropriate selectivity (for Fe3+ in H2O), recycling stability, and fast response times in N,N-dimethylformamide. Moreover, LCU-103 also displays good luminescent quenching activity toward Fe3+ in H2O and a simulated 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid biological system with low LODs of 1.51 and 1.52 μM, respectively. LCU-103 test papers were further prepared to offer easy and real-time detection of Fe3+ and Cu2+ ions. Importantly, when density functional theory calculations and multiple experimental evidence, including X-ray photoelectron spectroscopy, UV-vis absorption, luminescence decay lifetimes, and quantum efficiencies, are combined, a preferred N-donor site and possible weak interaction sensing mechanism is also proposed to elucidate the quenching effect.

Ultra-thin Bi2WO6 porous nanosheets with high lattice coherence for enhanced performance for photocatalytic reduction of Cr(VI).

Abstract: Bi2WO6 porous nanosheets (PNS) with different thickness were synthesized via one-pot hydrothermal method. The thickness of Bi2WO6 nanosheets could be well controlled from ∼27 nm to ∼16 nm by adjusting the precursor concentration. In addition, the PNS exhibited porous structures, high surface area and high lattice coherence, which increased the number of catalytic sites and facilitated the charge migration within the sheet structure. The Cr(VI) reduction experiments showed that the photocatalytic activity was greatly affected by the thickness of the product and the optimal photocatalytic activity under visible light irradiation was achieved by BWO-3 with thickness of ∼18 nm. The photocatalytic ratio of Cr(VI) reduction for BWO-3 reached to ∼99.5% after 100 min visible light irradiation, which was higher than that of BWO (∼78%). Based on the optical and electrochemical measurements, BWO-3 had upshifted conduction band of 0.05 V, prolonged carriers’ lifetime of 2.03 ns and decreased carriers' recombination efficiency compared to BWO. These results endowed BWO-3 with high photoreduction ability, increased transfer and separation efficiency of carriers, and thus enhanced the photoreduction activity.