Origin of Electrocatalytic Activity in Amorphous Nickel-Metalloid Electrodeposits


Sarac B., Karazehir T., Micusik M., Halkali C., Gutnik D., Omastova M., ...Daha Fazla

ACS APPLIED MATERIALS & INTERFACES, cilt.13, sa.20, ss.23689-23701, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 13 Sayı: 20
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1021/acsami.1c03007
  • Dergi Adı: ACS APPLIED MATERIALS & INTERFACES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Compendex, EMBASE, INSPEC, MEDLINE
  • Sayfa Sayıları: ss.23689-23701
  • İstanbul Teknik Üniversitesi Adresli: Evet

Özet

In transition metal-based alloys, the nonlinearity of the current at large cathodic potentials reduces the credibility of the linear Tafel slopes for the evaluation of electrocatalytic hydrogen activity. High-precision nonlinear fitting at low current densities describing the kinetics of electrochemical reactions due to charge transfer can overcome this challenge. To show its effectiveness, we introduce a glassy alloy with a highly asymmetric energy barrier: amorphous NiP electrocoatings (with different C and O inclusions) via changing the applied DC and pulsed current and NaH2PO2 content. The highest hydrogen evolution reaction (HER) activity with the lowest cathodic transfer coefficient alpha = 0.130 with high J(0) = -1.07 mA cm(-2) and the largest surface areas without any porosity are observed for the pulsed current deposition. The calculated alpha has a direct relation with morphology, composition, chemical state and coating thickness defined by the electrodeposition conditions. Here, a general evaluation criterion with practicality in assessment and high accuracy for electrocatalytic reactions applicable to different metallic alloy systems is presented.