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Start Over Author "Yan Dong" Publisher american chemical society
284 results on '"Yan Dong"'

4. NiCo2O4 Electrocatalyst Doped with Phosphorus for Improved Oxygen Evolution Reaction.

Author

Li, Shu-Fang, Li, Xin, and Yan, Dong

Abstract

Spinel oxides are affordable transition-metal electrocatalytic materials, but their low conductivity and intrinsic activity restrict their wide application in electrolyzed water catalysts. In this study, a series of heterojunction samples comprising phosphorus-doped spinel oxides NiCo2O4 in collaboration with g-C3N4 (NCPx@C3N4, x = 0.25, 0.50, 0.75) were fabricated through a straightforward mixture method for water splitting. Therein, the NCP0.5@C3N4 electrocatalyst exhibits remarkable performance compared to the other synthesized compounds, demonstrating a small overpotential of 247 mV at 10 mA cm–2 for the oxygen evolution reaction (OER), a favorable Tafel slope of 48 mV dec–1, and decent durability. The collaborative interaction between phosphorus doping and g-C3N4 results in the creation of numerous oxygen defects, increasing the electrochemically active surface area in NCP0.5@C3N4 and demonstrating a direct enhancement of the OER. Density functional theory (DFT) calculations verified that the introduction of phosphorus and its collaboration with g-C3N4 effectively regulated the electronic structure and optimized the d-band center position. Based on the results, a resilient synergistic interaction between NCP0.5 and C3N4 sheets contributes to the enhanced electrocatalytic activity of NCP0.5@C3N4. [ABSTRACT FROM AUTHOR]

Published
2024
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41. Alternative thermodiffusion interface for simultaneous speciation of organic and inorganic lead and mercury species by capillary GC-ICPMS using tri-n-propyl-lead chloride as an internal standard

Author

Yan, Dong, Yang, Limin, and Wang, Qiuquan

Subjects
Gas chromatography -- Methods, Mass spectrometry -- Methods, Plasma spectroscopy -- Methods, Lead -- Properties, Mercury -- Properties, Thermal diffusivity -- Research, Chemistry
Abstract

An alternative thermodiffusion interface (TDI) was designed and constructed for the effective online coupling of capillary gas chromatography (cGC) and inductively coupled plasma mass spectrometry (ICPMS). [Pb.sup.2+], [([CH.sub.3]).sub.3][Pb.sup.+], [([C.sub.2] [H.sub.5]).sub.3][Pb.sup.2+], [Hg.sup.2+], [CH.sub.3][Hg.sup.+] and [C.sub.2][H.sub.5][Hg.sup.+] were derived as Pb[([C.sub.4] [H.sub.9]).sub.4], [([CH.sub.3]).sub.3]Pb[C.sub.4][H.sub.9], [(C.sub.2] [H.sub.5]).sub.3]Pb[C.sub.4][H.sub.9], [([C.sub.4][H.sub.9]).sub.2]Hg, [CH.sub.3]Hg[C.sub.4][H.sub.9], and [C.sub.2][H.sub.5]Hg[C.sub.4] [H.sub.9] when butyl magnesium bromide was employed as a derivatization reagent for a proof-of-concept study, avoiding the loss of their species specific information. All these derivatives together with the neutral fully saturated [([CH.sub.3]).sub.4]Pb and [([C.sub.2] [H.sub.5]).sub.4]Pb could be quantitatively separated within 7 min using a 15 m long capillary column, allowing the determination and speciation of organic and inorganic Pb and Hg species in a single run. The method detection limits (3[sigma]) for [Me.sub.4]Pb, [Et.sub.4]Pb, [Me.sub.3][Pb.sup.3+], [Pb.sup.2+], Me[Hg.sup.+], Et[Hg.sup.+], and [Hg.sup.2+] are 0.07, 0.06, 0.04, 7.0, 0.09, 0.1, and 0.2 pg [g.sup.-1], respectively. Moreover, tri-n-propyl-lead chloride was synthesized and used as an alternative internal standard for the accurate and simultaneous speciation analysis of Pb and Hg in complicated environmental and biological samples for the first time. This cGC-TDI-ICPMS method was validated by analyzing Pb and Hg species in certified reference materials and then was applied to simultaneous speciation analysis of Pb and Hg in reallife samples. It is expected that these approaches can be extended to the speciation of other organometallic compounds after suitable modifications and so will aid in monitoring the occurrence, pathways, toxicity, and/or biological effects of these compounds in the environment and in organisms.

Published
2008

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