Metal-free amino-graphdiyne for applications in electrocatalytic hydrogen evolution

Graphdiyne-based metal-free catalysts demonstrate outstanding performances in electrocatalysis. In order to accurately understand the activity origin of metal-free electrocatalytic hydrogen production at the atomic level, we have successfully designed and prepared a new metal-free catalyst of 1,2,4-triamino-graphdiyne (TAGDY). Structural characterizations showed that TAGDY has unique nanostructure, which guarantees the fast proton-electron transfer during the catalytic process. Experimental studies revealed that TAGDY possesses excellent electrocatalytic activities and long-term durability towards hydrogen evolution in acidic conditions, better than the most reported metal-free electrocatalysts. Density functional theory calculations and Born-Oppenheimer molecular dynamics simulations revealed that the interaction of (H++e) pair with alkyne bond induces the transition between -C equivalent to C- and -C equivalent to C- in TAGDY, which effectively enhanced the catalytic activities of initial inert carbon sites. Combination of theory and experiment as well as the structural characterization, a new level of knowledge for the activity origin and catalytic mechanism of graphdiyne-based metal-free electrocatalysts are presented. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Graphdiyne-based metal-free catalysts, such as 1,2,4-triamino-graphdiyne (TAGDY), exhibit excellent electrocatalytic performances for hydrogen evolution in acidic conditions due to their unique nanostructure facilitating fast proton-electron transfer. Experimental studies and theoretical calculations reveal that TAGDY enhances catalytic activities by inducing transition between certain carbon sites, presenting a new level of understanding for the catalytic mechanism of metal-free catalysts.