Pd Ion‐Exchange and Ammonia Etching of a Prussian Blue Analogue to Produce a High‐Performance Water‐Splitting Catalyst. (13th December 2020)

• Record Type: Journal Article
• Authors: Zhang, Hao; Jiang, Qianfan; Hadden, Joseph H. L.; Xie, Fang; Riley, D. Jason
• Is Part Of: Advanced functional materials. Volume 31:Number 10(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-13
• Subjects: cation‐exchanges -- CoPd2 -- dodecagon nanosheets -- overall water‐splitting -- Prussian blue analogues; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202008989
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The authors report an ammonia‐assisted in situ cation‐exchange method for the synthesis of dodecagon N‐doped PdCoNi carbon‐based nanosheets (Pd‐e‐NiCo‐PBA‐C) and explore the catalytic performance. Pd‐e‐NiCo‐PBA‐C exerts extremely low overpotential and Tafel slope for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) both in acidic and alkaline media, only 47 mV, 55 mV dec −1 (pH = 0, HER) and 147 mV, 67 mV dec −1 (pH = 14, HER), and 309 mV, 67 mV dec −1 (pH = 14, OER), outperforming commercial IrO2 ‐based and Pt‐based catalysts. In addition, after 5000 cycles, the linear sweep voltammetry curve shows a negligible shift, indicating excellent stability performance. To test its overall water‐splitting performance, Pd‐e‐NiCo‐PBA‐C is applied as both cathode and anode materials. A high current density of 33 mA cm −2 at a battery voltage of 1.6 V is obtained, with the catalytic activity maintained at 97.3% after over 50 h. To get a further insight into the superior OER and HER performance, theoretical calculations are carried out, the better performance originates from the affinity difference of Pd and Ni atoms for gas atoms, and the replacement of inert atoms can decrease the binding energy and enhance the electrocatalytic activity. Abstract : Multicomponent composite nanoparticles are prepared by the ammonia etching and Pd‐ion exchange of a Co‐Ni Prussian blue analogue and the subsequent calcination to yield CoPd2 linked to carbon‐based nanosheets. The synergistic effect of CoPd2, with nitrogen doping, and the 2D nanosheet structures results in excellent hydrogen evolution and oxygen evolution performance of the catalyst.