• Title/Summary/Keyword: transition metal

Search Result 1,212, Processing Time 0.279 seconds

Transition Metal-Based Layered Double Hydroxides for Oxygen Evolution Reaction Catalysts (전이금속 이중층 수산화물 기반 산소발생반응 촉매 연구 동향)

  • Da-Un Han;Gyeongbae Park
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.37 no.4
    • /
    • pp.358-373
    • /
    • 2024

  • Oxygen evolution reaction is a critical bottleneck for the development of efficient electrochemical hydrogen production because of its sluggish reaction. Among various catalysts, transition metal-based layered double hydroxide has drawn significant attention due to their excellent catalytic properties and cost-effectiveness. This paper begins with basic crystal structures, and then conventional adsorbate evolution mechanism of layered double hydroxide. Strategies for enhancing catalytic properties based on adsorbate evolution mechanism and lattice oxygen mechanism that could surpass theoretical limit of adsorbate evolution mechanism are discussed. This paper ends with a brief discussion on the challenges and future directions of layered double hydroxide-based oxygen evolution reaction catalysts.

  • https://doi.org/10.4313/JKEM.2024.37.4.2 인용 PDF

Chemiluminescence System with Air Pump as a Sensor for Determination of Metal Levels in Rain

  • Hong, Hyuck-Gi;Lim, H.B.
    • Bulletin of the Korean Chemical Society
    • /
    • v.26 no.12
    • /
    • pp.1937-1940
    • /
    • 2005

  • A lab-made chemiluminescence system with air pump was developed for monitoring of some metal levels in rain. The air pump enabled injection of 17.7 $\mu$g samples into a glass cell filled with luminol-$H_2O_2$ reagent of typically 300 $\mu$L for chemiluminescence measurement. The monitored trend of total metal ions in the rain collected in our campus was compared with analytical results of each metal ion from GFAAS. The system was also demonstrated to determine $Cr^{6+}$ by reduction to $Cr^{3+}$ using $SnCl_2$. The limit of detection for $Cr^{6+}$ obtained by 4 measurements was 85.0 pg $mL^{-1}$ with a relative standard deviation of 3.4%. Although this system doesn’t have selectivity due to the characteristics of chemiluminescence, application of it to environmental monitoring as a sensor for some transition metal ions was demonstrated.

  • https://doi.org/10.5012/bkcs.2005.26.12.1937 인용 PDF KSCI

Electrical Phase Transition of Poly (4,4'-Aminotriphenylene Hexafluoroisopropylidenediphthalimide) by Photogenerated Charged Carrier Injection

  • Im, Gyu-Uk;Lee, Gyeong-Jae;Lee, Mun-Ho;Gang, Tae-Hui;Jeong, Seok-Min;Yang, Mi-Hyeon;Kumar, Yogesh
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.02a
    • /
    • pp.266-266
    • /
    • 2013

  • We show a set-up of poly (4,4'-aminotriphenylene hexafluoroisopropylidenediphthalimide) (6F-TPA PI)/Al sample in which holes are injected by photoelectron emission process instead of direct charge carrier injection via metal electrode. In this process, an irreversible electrical phase transition of 6F-TPA PI is found in contrast to the Al/6F-TPA PI/Al structure, leading to a write-once-readmany behavior. The photoelectron spectroscopy results measured before and after the switching process revealed that the irreversible electrical phase transition of 6F-TPA PI is attributed to the chemical modification of the carbonyl group in phthalimide moiety.

  • PDF