The ability to craft high-performance and cost-effective bifunctional oxygen catalysts opens up pivotal perspectives for commercialization of zinc-air batteries (ZABs). Despite recent grand advances in the development of synthetic techniques,...

The ability to craft high‐efficiency and non‐precious bifunctional oxygen catalysts opens an enticing avenue for the real‐world implementation of metal‐air batteries (MABs). Herein, Co3O4 encapsulated within nitrogen defect‐rich g‐C3N4 (denoted Co3O4@ND‐CN) as a bifunctional oxygen catalyst for MABs is prepared by graphitizing the zeolitic imidazolate framework (ZIF)‐67@ND‐CN. Co3O4@ND‐CN possesses superb bifunctional catalytic performance, which facilitates the construction of high‐performance MABs. Concretely, the rechargeable zinc‐air battery based on Co3O4@ND‐CN shows a superior round‐trip efficiency of ≈60% with long‐term durability (over 340 cycles), exceeding the battery with the state‐of‐the‐art noble metals. The corresponding lithium‐oxygen battery using Co3O4@ND‐CN exhibits an excellent maximum discharge/charge capacity (9838.8/9657.6 mAh g−1), an impressive discharge/charge overpotential (1.14 V/0.18 V), and outstanding cycling stability. Such compelling electrocatalytic processes and device performances of Co3O4@ND‐CN originate from concurrent compositional (i.e., defect‐engineering) and structural (i.e., wrinkled morphology with abundant porosity) elaboration as well as the well‐defined synergy between Co3O4 and ND‐CN, which produce an advantageous surface electronic environment corroborated by theoretical modeling. By extension, a rich diversity of other metal oxides@ND‐CN with adjustable defects, architecture, and enhanced activities may be rationally designed and crafted for both scientific research on catalytic properties and technological development in renewable energy conversion and storage systems.

Though solar cells are one of the promising technologies to address the energy crisis, this technology is still far from commercialization. Thermoelectric materials offer a novel opportunity to convert energy between thermal and electrical aspects, which show the feasibility to improve the performance of solar cells via heat management and light harvesting. Polymer–inorganic thermoelectric nanocomposites consisting of inorganic nanomaterials and functional organic polymers represent one kind of advanced hybrid nanomaterials with tunable optical and electrical characteristics and fascinating interfacial and surface chemistry. During the past decades, they have attracted extensive research interest due to their diverse composition, easy synthesis, and large surface area. Such advanced nanomaterials not only inherit low thermal conductivity from polymers and high Seebeck coefficient, and high electrical conductivity from inorganic materials, but also benefit from the additional interface between each component. In this review, we provide an overview of interfacial chemistry engineering and electrical feature of various polymer–inorganic thermoelectric hybrid nanomaterials, including synthetic methods, properties, and applications in thermoelectric devices. In addition, the prospect and challenges of polymer–inorganic nanocomposites are discussed in the field of thermoelectric energy.