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

Abstract

AbstractThe irreconcilable conflict between stability and excellent electrocatalytic activity of Au nanoclusters greatly limits their application. Extensive efforts are devoted to fabricating various substrates to immobilize Au nanoclusters while it is still challenging to maintain its electrocatalytic activities for long term tasks due to the highly reactive environments that the Au nanoclusters encounter in electrocatalytic reactions. Herein, an unexpected “redispersion effect” is discovered when Au25 nanoclusters are loaded on the nanocomposites of black phosphorus and N‐doped graphene (AuCs/BP‐NG), forming the sandwich configuration with the enhanced stability. The size of Au nanoclusters reduce from 1.56 ± 0.5 to 1.04 ± 0.2 nm, leading to improved catalytic ability. Such redispersion effect yields a super‐high electrocatalytic performance of the AuCs/BP‐NG toward Cr(VI) sensing that the detection sensitivity achieved 0.414 µA ppb−1, which is two orders of magnitude higher than the state‐of‐the‐art value. Compared with BP‐NG and Au nanoparticles (AuNPs) loaded on BP‐NG (AuNPs/BP‐NG), the lowest reaction barrier in the rate‐determining steps of H2CrO4 reduction is observed. The findings provide an opportunity to develop a superior electrocatalyst in the community of energy and environment‐related electrocatalysis.