The two-dimensional boron monolayer (borophene) stands out from the two-dimensional atomic layered materials due to its structural flexibility and tunable electronic and mechanical properties from a large number of allotropic materials. The stability of pristine borophene polymorphs could possibly be improved via hydrogenation with atomic hydrogen (referred to as borophane). However, the precise adsorption structures and the underlying mechanism are still elusive. Employing first-principles calculations, we demonstrate the optimal configurations of freestanding borophanes and the ones grown on metallic substrates. For freestanding borophenes, the energetically favored hydrogen adsorption sites are sensitive to the polymorphs and corresponding coordination numbers of boron atoms. With various metal substrates, the hydrogenation configurations of borophenes are modulated significantly, attributed to the overlap between B p z and H s orbitals. These findings provide a deep insight into the hydrogenating borophenes and facilitate the stabilization of two-dimensional boron polymorphs by engineering hydrogen adsorption sites and concentrations.

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A facile one-step method is developed to in situ prepare crystalline anatase and rutile TiO2 nanocrystalline on Ti3C2Tx by regulating the metastable Ti ions.

Graphynes (GYs) are a novel type of carbon allotrope composed of sp and sp2 hybridized carbon atoms, boasting both a planar conjugated structure akin to graphene and a pore‐like configuration in three‐dimensional space. Graphdiyne (GDY), the first successfully synthesized member of GYs family, has gained much interest due to its fascinating electrochemical properties including a greater theoretical capacity, high charge mobility and advanced electronic transport properties, making it a promising material for energy storage applications for lithium‐ion and hydrogen storage. Various methods, including heteroatom substitution, embedding, strain, and nanomorphology control, have been employed to further enhance the energy storage performance of GDY. Despite the potential of GDY in energy storage applications, there are still challenges to overcome in scaling up mass production. This review summarizes recent progress in the synthesis and application of GDY in lithium‐ion and hydrogen storage, highlighting the obstacles faced in large‐scale commercial application of GDY‐based energy storage devices. Suggestions on possible solutions to overcome these hurdles have also been provided. Overall, the unique properties of GDY make it a promising material for energy storage applications in lithium‐ion and hydrogen storage devices. The findings presented here will inspire further development of energy storage devices utilizing GDY.