Additive manufacturing (AM) has gained significant attention due to its ability to drive technological development as a sustainable, flexible, and customizable manufacturing scheme. Among the various AM techniques, direct ink writing (DIW) has emerged as the most versatile 3D printing technique for the broadest range of materials. DIW allows printing of practically any material, as long as the precursor ink can be engineered to demonstrate appropriate rheological behavior. This technique acts as a unique pathway to introduce design freedom, multifunctionality, and stability simultaneously into its printed structures. Here, a comprehensive review of DIW of complex 3D structures from various materials, including polymers, ceramics, glass, cement, graphene, metals, and their combinations through multimaterial printing is presented. The review begins with an overview of the fundamentals of ink rheology, followed by an in‐depth discussion of the various methods to tailor the ink for DIW of different classes of materials. Then, the diverse applications of DIW ranging from electronics to food to biomedical industries are discussed. Finally, the current challenges and limitations of this technique are highlighted, followed by its prospects as a guideline toward possible futuristic innovations.

Hexagonal boron nitride (h-BN) has emerged as a strong candidate for twodimensional (2D) material owing to its exciting optoelectrical properties combined with mechanical robustness, thermal stability, and chemical inertness. Super-thin h-BN layers have gained significant attention from the scientific community for many applications, including nanoelectronics, photonics, biomedical, anti-corrosion, and catalysis, among others. This review provides a systematic elaboration of the structural, electrical, mechanical, optical, and thermal properties of h-BN followed by a comprehensive account of stateof-the-art synthesis strategies for 2D h-BN, including chemical exfoliation, chemical, and physical vapor deposition, and other methods that have been successfully developed in recent years. It further elaborates a wide variety of processing routes developed for doping, substitution, functionalization, and combination with other materials to form heterostructures. Based on the extraordinary properties and thermal-mechanical-chemical stability of 2D h-BN, various potential applications of these structures are described.The ORCID identification number(s) for the author(s) of this article can be found under

Covalent organic frameworks (COFs) have emerged as an exciting new class of porous materials constructed by organic building blocks via dynamic covalent bonds. They have been extensively explored as potentially superior candidates for electrode materials, electrolytes, and separators, due to their tunable chemistry, tailorable structures, and well‐defined pores. These features enable rational design of targeted functionalities, facilitate the penetration of electrolytes, and enhance ion transport. This review provides an in‐depth summary of the recent progress in the development of COFs for diverse battery applications, including lithium‐ion, lithium–sulfur, sodium‐ion, potassium‐ion, lithium–CO2, zinc‐ion, zinc–air batteries, etc. This comprehensive synopsis pays particular attention to the structure and chemistry of COFs and novel strategies that have been implemented to improve battery performance. Additionally, current challenges, possible solutions, and potential future research directions on COFs for batteries are discussed, laying the groundwork for future advances for this exciting class of material.

As the price of renewable electricity continues to plummet, hydrogen (H2) production via water electrolysis is gaining momentum globally as a route to decarbonize our energy systems. The requirement of...

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