Polymer/Graphene Composite with Multiple Active Sites Enables Membrane‐Free Decoupled Hydrogen Production in Acidic Electrolyte

Decoupled water electrolysis using solid-state redox mediators (SRMs) enables spatial and temporal separation of hydrogen and oxygen production without relying on membranes. Here, a nitrogen-containing heterocyclic quinone polymer (PYTQ) was integrated with reduced graphene oxide (RGO) via vacuum-assisted filtration to synthesize the composite material (PYTQ-RGO). Benefiting from the multiple active sites for PYTQ and the strong π-π interactions between PYTQ and RGO, the composite exhibits high specific capacity and excellent stability. A membrane-free decoupled water electrolysis architecture is successfully achieved using PYTQ-RGO as a solid-state redox mediator, which could be driven by renewable energies.