Enhancing electrocatalytic performance and Stability: A novel Prussian Blue-Graphene quantum dot nanoarchitecture for H₂O₂ reduction

The reduction reaction of hydrogen peroxide (H2O2) stands as a pivotal electrochemical process holding the promise of revolutionizing energy conversion and water treatment applications. Realizing this potential hinges on the development of electrocatalysts that not only exhibit exceptional activity but also demonstrate unwavering stability. Herein, we propose a pioneering electrocatalyst composed of Prussian blue (PB)-graphene quantum dot (GQD) (PB-GQD) nanoarchitecture fabricated through an in-situ electrochemical method. The PB-GQD nanoarchitecture boasts precisely crafted PB nanoparticles (NPs) that exhibit remarkable electrochemical catalytic activity and stability, offering a substantial advancement over conventional PB NPs structure used as a control. The augmentation of electrocatalytic performance in the PB-GQD nanoarchitecture can be attributed to the symbiotic relationship between PB NPs and GQD. This synergy is engendered through electrostatic attraction and/or coordination interactions between PB precursor's iron cations and GQD's multivalent polyanions. This unique arrangement accelerates heterogeneous electron transport, endows the structure with abundant electrochemically active sites, and shortens mass transfer lengths. Notably, GQD's presence, rich with hydroxyl (-OH) and carboxylic (-COOH) groups, mitigates the decomposition of PB NPs into Fe(OH)(3) in neutral or higher pH solutions. This preservation mechanism ensures sustained, elevated electrocatalytic performance for H2O2 reduction.