Abstract Oxygen-enriched boron carbonitrides – known as boron carbon oxinitrides, BCNOs – have exhibited remarkable properties with numerous works reporting on their performance as phosphors and some few ones as H2-adsorbents. However, the study of BCNOs capability for CO2 uptaking has yet to be achieved. Herein, we have designed a simple process for preparation of freestanding three-dimensional (3D) BCNO structures via pyrolysis of supramolecular gels formed by H-bonding of melamine, boric acid and glucose. The 3D porous materials obtained by pyrolysis of supramolecular gels containing glucose exhibited a seaweed-like 3D structure formed by BCNO nanocrystals embedded within a carbonaceous matrix with a certain content of amorphous hydrogenated carbon. The particularly narrow porosities exhibited by these samples proved effective for CO2 adsorption with uptakes of up to ca. 1.8 mmol/g at 25 °C. More interestingly, those samples prepared with high concentration of glucose behaved as molecular sieves and exhibited an excellent performance for CO2–CH4 separation, especially at low pressures with kH values of up to 1.04∙103.

中文翻译：

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氢键超分子水凝胶作为制备含有 BCNO 纳米晶体并具有高 CO 2 /CH 4 吸附比的独立式 3D 碳质结构的有效前体

摘要 富氧硼碳氮化物 - 被称为硼碳氧氮化物，BCNOs - 已表现出卓越的性能，许多工作报告了它们作为磷光体的性能，以及一些作为 H2 吸附剂的性能。然而，对 BCNOs 吸收 CO2 能力的研究尚未完成。在此，我们设计了一种简单的方法，通过热解由三聚氰胺、硼酸和葡萄糖的 H 键形成的超分子凝胶来制备独立的三维 (3D) BCNO 结构。通过热解含有葡萄糖的超分子凝胶获得的 3D 多孔材料表现出类似海藻的 3D 结构，由嵌入具有一定含量无定形氢化碳的碳质基质中的 BCNO 纳米晶体形成。这些样品表现出的特别窄的孔隙率证明对 CO2 吸附有效，吸收量高达约 在 25°C 时为 1.8 mmol/g。更有趣的是，那些用高浓度葡萄糖制备的样品表现为分子筛，并表现出优异的 CO2-CH4 分离性能，尤其是在 kH 值高达 1.04∙103 的低压下。