Unexpected Redispersion Effect of Au Nanoclusters for Enormous Enhancement of Electrocatalytic Stability and Activity

摘要

The irreconcilable conflict between stability and excellent electrocatalytic activityof Au nanoclusters greatly limits their application. Extensive efforts are devotedto fabricating various substrates to immobilize Au nanoclusters while it is stillchallenging to maintain its electrocatalytic activities for long term tasks due tothe highly reactive environments that the Au nanoclusters encounter in electrocatalyticreactions. Herein, an unexpected “redispersion effect” is discoveredwhen Au_(25) nanoclusters are loaded on the nanocomposites of black phosphorusand N-doped graphene (AuCs/BP-NG), forming the sandwich configurationwith the enhanced stability. The size of Au nanoclusters reduce from 1.56 ± 0.5to 1.04 ± 0.2 nm, leading to improved catalytic ability. Such redispersion effectyields a super-high electrocatalytic performance of the AuCs/BP-NG towardCr(Ⅵ) sensing that the detection sensitivity achieved 0.414 μA ppb~(?1), which istwo orders of magnitude higher than the state-of-the-art value. Compared withBP-NG and Au nanoparticles (AuNPs) loaded on BP-NG (AuNPs/BP-NG), thelowest reaction barrier in the rate-determining steps of H_2CrO_4 reduction isobserved. The findings provide an opportunity to develop a superior electrocatalystin the community of energy and environment-related electrocatalysis.