Recent advances in nitrogen-doped graphdiyne and polyoxometalate–graphdiyne interfaces for energy conversion and storage

Graphdiyne (GDY) is a two-dimensional carbon allotrope constructed from both sp- and sp²-hybridized carbon atoms. Its -conjugated framework connected by butadiyne linkages combines regular nanopores, tunable electronic structures, and abundant chemically modifiable sites. Compared with pristine GDY, nitrogen-containing graphdiyne (N-GDY) provides diverse nitrogen configurations and, in metal-containing derivatives, metal–N coordination motifs; these features can redistribute local charge density, tune intermediate adsorption, and facilitate charge transport. Related composites combining polyoxometalates (POMs), molecular metal–oxo clusters with rich redox chemistry, and graphdiyne supports have been reported, whereas structurally defined POM/N-GDY interfaces remain less established. This review systematically summarizes the recent progress in N-GDY and POM/graphdiyne interfacial systems, covering bottom-up monomer design, post-doping/functionalization strategies, and structural characterization. The applications of these materials in electrocatalysis (ORR, OER, HER, , NRR), energy storage, photocatalysis, sensing, and interfacial engineering are discussed. In N-GDY systems, the role of nitrogen is better understood in terms of site chemistry rather than overall doping level. Different N configurations, including pyridinic, imine-type, sp-N, sp²-N and metal-N coordination sites, can polarize adjacent sp/sp² carbon atoms, regulate intermediate adsorption, and alter interfacial charge-transfer pathways. For reported POM/graphdiyne hybrids and proposed POM/N-GDY interfaces, these effects may couple with POM–carbon interactions and thereby influence cluster retention, redox behavior, and catalytic stability. Finally, the remaining challenges related to precise nitrogen-site and POM-interface construction, scalable synthesis, in situ characterization, identification of true active sites, and device-level validation are discussed, together with possible future directions.