Recent advances in nanostructured materials for high-performance supercapacitors and electrochemical water splitting applications

The pressing need for efficient and sustainable energy systems has spurred rapid advancements in materials science that can handle energy conversion and storage. Nanostructured materials are among the most promising options with their distinct physicochemical characteristics, including a high surface area, adjustable porosity, improved electrical conductivity, and a large number of electroactive sites. Recent advancements in porous carbons, heteroatom-doped carbons, MXenes, and transition-metal oxides, sulfides, and phosphides have made it possible for supercapacitors to have qualities that allow for quick charge storage, high power density, and long-term cycle stability. In contrast, nanostructured catalysts, such as perovskites, transition-metal dichalcogenides, layered double hydroxides, and single-atom systems, have shown remarkable activity and durability for the hydrogen evolution reaction and oxygen evolution reaction in electrochemical water splitting. The convergence of design methodologies for both applications is a significant finding from recent research. The creation of bifunctional electrodes and integrated hybrid platforms is made possible by the shared needs of supercapacitors and water-splitting systems, which include high conductivity, accessible redox-active sites, and strong structural stability. Notwithstanding these developments, there are still significant obstacles to overcome, such as the absence of standardized benchmarking procedures, the limited long-term durability under realistic operating circumstances, and the inadequate scalability of synthesis techniques. To bridge laboratory-scale innovations with practical implementation, these challenges must be addressed by operando characterization, sustainable manufacturing approaches, and computationally driven materials discovery. This review focuses on the fundamental synergies in material design, covers current developments in nanostructured materials for electrochemical water splitting and high-performance supercapacitors, and describes obstacles and potential directions. These complementary technologies may be used to create multipurpose energy systems that combine sustainable hydrogen generation with quick energy storage, providing a possible route to a carbon-neutral energy future.