Electrocatalytic oxygen reduction performances of surface Ag granular packs electrodeposited from dual-phase Ag35.5Zn64.5 precursor alloys by triangle wave potential cycling

• 作者: Jia-Yu Luo Piao-Piao Han Zhen-Hua Dan Tao Tang Feng-Xiang Qin Hui Chang Lian Zhou
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（12）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 3531-3542
• 页数: 12页
• 语种: 英文

摘要

Surface Ag granular packs (SAgPs) have been fabricated from dual-phase Ag35.5Zn64.5 precursor alloy consisting of both ε and γ phases by using a facile one-step triangle wave potential cycling in 0.5 mol·L-1 KOH.During the continuous potential cyclic sweeping,the γ phases preferentially dissolve during the anodic scan and dominant reduction reactions of Ag cations lead to rede-position and accumulation of Ag atoms together to form SAgPs during cathodic scan.The ε phases stay inactive to form a continuous skeleton in the inner regions.SAgPs with an average particle size of 94-129 nm can be obtained at scan rates of 25,50 and 100 mV·s-1 for 100 triangle wave potential cycles.SAgPs formed at a scan rate of 50 mV·s-1 exhibit superior oxygen reduction reaction performances with the onset potential of 0.93 V,half-wave potential of 0.72 V and an electron transfer number of 4.0.The above-mentioned SAgPs have superior stabilities as ORR catalysts.