Water Electrolysis Using Thin Pt and RuO x Catalysts Deposited by a Flame-Annealing Method on Pencil-Lead Graphite-Rod Electrodes

Ryuki Tsuji; Yuuki Koshino; Hideaki Masutani; Yuichi Haruyama; Masahito Niibe; Satoru Suzuki; Seiji Nakashima; Hironori Fujisawa; Seigo Ito

doi:10.1021/acsomega.0c00074

Water Electrolysis Using Thin Pt and RuO _x Catalysts Deposited by a Flame-Annealing Method on Pencil-Lead Graphite-Rod Electrodes

ACS Omega. 2020 Mar 12;5(11):6090-6099. doi: 10.1021/acsomega.0c00074. eCollection 2020 Mar 24.

Authors

Ryuki Tsuji¹, Yuuki Koshino¹, Hideaki Masutani¹, Yuichi Haruyama^{1

2}, Masahito Niibe^{1

2}, Satoru Suzuki^{1

2}, Seiji Nakashima³, Hironori Fujisawa³, Seigo Ito¹

Affiliations

¹ Department of Materials and Synchrotron Radiation Engineering, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan.
² Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Ako, Hyogo 678-1205, Japan.
³ Department of Electronics and Computer Science, Graduate School of Engineering, University of Hyogo. Shosha, Himeji, Hyogo 671-2280, Japan.

Abstract

An inexpensive, simple, and high-activity catalyst preparation method has been introduced in this work. Pt and RuO _x catalysts were fabricated by soaking inexpensive graphite electrodes (pencil-lead graphite rod: PGR) in catalyst precursor solutions and using a simple flame-annealing method, which results in lower amount of Pt and RuO _x catalyst layers. From X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure analysis, it has been found that platinum and ruthenium were deposited as zero-valence metal (Pt) and oxide (RuO _x ), respectively. Catalytic activities of Pt/PGR and RuO _x /PGR for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were evaluated using neutral 1 M Na₂SO₄ aqueous electrolyte, respectively. Although HER and OER currents using PGR without catalysts were -16 mA cm^-2 (at -1.5 V vs Ag/AgCl) and +20 mA cm^-2 (at +2.0 V vs Ag/AgCl), they were improved to -110 and +80 mA cm^-2 with catalysts (Pt and RuO _x ), respectively. Such an inexpensive and rapid catalyst electrode preparation method on PGR using flame-annealing is a very significant method in the initial catalyst activity evaluation requiring a large amount of trial and error.