Structural study of atomically precise doped Au38−xAgx NCs@ZIF-8 electrode material for energy storage application

Abstract

Fast-charging storage devices have attained attention in recent years due to their prospective wide range of applications in microelectronic gadgets and hybrid electric vehicles. In the pursuit of new efficient high-capacity electrodes, the implication of atomically precise metal nanoclusters (NCs) in the field of supercapacitors is rare. Herein, structurally distorted atomically precise doped Au38−xAgx NCs protected by 2,4-dimethylbenzenethiolate (2,4-DMBT) were synthesized by doping Ag atoms to the parent monometallic Au38 NCs. A general strategy to integrate structurally distorted atomically precise doped Au38−xAgx NCs with ZIF-8 (Au38−xAgx NCs@ZIF-8) was employed for methodical electrochemical and physicochemical studies of intrinsic energy storage mechanisms. The structural changes of doped Au38−xAgx NCs@ZIF-8 were systematically revealed and the effect of heteroatom doping, synergistic effect, reduced HOMO-LUMO gap (HLG) of highly distorted doped Au38−xAgx NCs@ZIF-8 resulted in enhanced electronic transfer kinetics, ultimately improving specific capacitance 2.2 times higher than the parent monometallic Au38 NCs. Doped Au38−xAgx NCs@ZIF-8 based hybrid supercapacitor (HSC) provides a high energy density of 14.75 Wh kg−1 and power density of 2212.8 W kg−1. The development of structurally distorted atomically precise doped Au38−xAgx NCs@ZIF-8 electrode material can pave the ways for doped metal nanoclusters for next-generation energy storage devices.