Evolution of silver to a better electrocatalyst: Water-assisted oxygen reduction reaction at silver chloride nanowires in alkaline solution. (June 2018)

• Record Type: Journal Article
• Authors: Kim, Su-jin; Lee, Seung-Cheol; Lee, Chongmok; Kim, Myung Hwa; Lee, Youngmi
• Is Part Of: Nano energy. Volume 48(2018)
• Page Start: 134
• Page End: 143
• Publication Date: 2018-06
• Subjects: Oxygen reduction reaction -- Electrocatalysis -- Silver halide -- Nanowires -- DFT calculation; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.03.041
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: Oxygen reduction reaction (ORR) is of great interest in various areas, including energy conversion. This paper presents the simple synthesis and characterization of one-dimensional silver halides nanowires (AgClNW and AgBrNW) as an electrocatalyst for ORR in alkaline media, as well as an investigation of the ORR pathway at AgCl. AgClNW and AgBrNW were prepared via a galvanic replacement reaction (GRR) between silver nanowires (AgNW) and a halide precursor. AgClNW exhibited excellent ORR catalytic activity that was comparable to or better than that for commercial Pt (20 wt% Pt loading on Vulcan carbon), demonstrating potential to replace Pt-based catalysts. A scanning electrochemical microscopy (SECM) analysis supports the existence of an associative ORR pathway at AgCl, and first-principles density functional theory (DFT) calculations suggest that the high ORR activity of AgCl is possibly attributed to the up-shifted Ag d-band center energy in AgCl as well as the assistance of adsorbed water molecules. Graphical abstract: Silver chloride nanowires show an excellent electrocatalytic activity for oxygen reduction reaction via water assistance. fx1 Highlights: AgCl nanowires show an excellent catalytic activity for oxygen reduction reaction. AgCl nanowires are synthesized from Ag nanowires via galvanic replacement reaction. d-band center energy of Ag in AgCl is upshifted to become closer to that of Pt. Water adsorption on AgCl plays a critical role in the improved activity of AgCl.