The assembly of molecules to form covalent networks can create varied lattice structures with physical and chemical properties distinct from those of conventional atomic lattices. Using the smallest stable [5,6]fullerene units as building blocks, various 2D C₂₄ networks can be formed with superior stability and strength compared to the recently synthesized monolayer polymeric C₆₀. Monolayer C₂₄ harnesses the properties of both carbon crystals and fullerene molecules, such as stable chemical bonds, suitable band gaps, and large surface area, facilitating photocatalytic water splitting. The electronic band gaps of C₂₄ are comparable to those of TiO₂, providing appropriate band edges with sufficient external potential for overall water splitting over the acidic and neutral pH range. Upon photoexcitation, strong solar absorption enabled by strongly bound bright excitons can generate carriers effectively, while the type-II band alignment between C₂₄ and other 2D monolayers can separate electrons and holes in individual layers simultaneously. Additionally, the number of surface-active sites of C₂₄ monolayers are three times more than that of their C₆₀ counterparts in a much wider pH range, providing spontaneous reaction pathways for the hydrogen evolution reaction. Our work provides insights into materials design using tunable building blocks of fullerene units with tailored functions for energy generation, conversion, and storage.

中文翻译：

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最小的 [5,6] 富勒烯作为 2D 网络的构建块，具有卓越的稳定性和增强的光催化性能


分子组装形成共价网络可以产生不同的晶格结构，其物理和化学性质与传统原子晶格不同。使用最小的稳定 [5,6] 富勒烯单元作为构建单元，可以形成各种 2D C₂₄ 网络，与最近合成的单层聚合物 C₆₀ 相比，具有卓越的稳定性和强度。单层 C₂₄ 利用了碳晶体和富勒烯分子的特性，例如稳定的化学键、合适的带隙和大表面积，促进了光催化分解水。C₂₄ 的电子带隙与 TiO₂ 的电子带隙相当，为在酸性和中性 pH 范围内的整体水分解提供了适当的带边缘和足够的外部电位。在光激发时，强结合的明亮激子实现的强太阳吸收可以有效地产生载流子，而 C₂₄ 和其他 2D 单层之间的 II 型带对齐可以同时分离各个层中的电子和空穴。此外，在更宽的 pH 范围内，C₂₄ 单层的表面活性位点数量是 C₆₀ 对应物的三倍，为析氢反应提供了自发反应途径。我们的工作使用富勒烯单元的可调构建块为材料设计提供了见解，这些单元具有用于能源产生、转换和储存的定制功能。