This study developed a method to fabricate a surface-oxidized rigid carbon foam (ORCF) with hierarchical macro-nanoporous structure via KOH activation of the carbon foam with two kinds of macropores followed by HNO₃ hydrothermal oxidation. The structures of the prepared ORCF were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy, and N₂ adsorption-desorption analyzer. Results demonstrate that the ORCF possesses a fluffy and porous structure with rich oxygen-containing groups. There are numerous through-holes on its pore surfaces connected with two-level macropores forming hierarchical macroporous channels. Meanwhile, the ORCF remains a good bulk structure with a compression strength of 0.74 MPa at a bulk density of 0.09 g cm⁻³. Batch adsorption experiments for malachite green (MG) and Pb²⁺ were studied through the single variable method to investigate the effects of different initial conditions on its adsorption process. The ORCF has maximum adsorption capacities for MG and Pb²⁺ of 587.68 mg g⁻¹ and 157.80 mg g⁻¹ with high partition coefficients of 17.41 mg g⁻¹ µM⁻¹ and 14.86 mg g⁻¹ µM⁻¹, respectively. The experimental data are suitable for Langmuir isotherm and Pseudo-second-order kinetic models, which correspond to monolayer chemisorption. Thermodynamic analysis indicates that the adsorption process is spontaneous and endothermic. Moreover, the removal percentages of MG and Pb²⁺ by the ORCF could remain above 90% after five cycles, implying that the ORCF is an efficient adsorbent with good adsorption ability and cycling stability.

本研究开发了一种通过 KOH 活化具有两种大孔的碳泡沫，然后进行 HNO ₃水热氧化来制造具有分级大纳米孔结构的表面氧化硬质碳泡沫 (ORCF) 的方法。使用扫描电子显微镜、透射电子显微镜、X 射线衍射、傅里叶变换红外 (FTIR) 光谱、X 射线光电子能谱和 N ₂表征制备的 ORCF 的结构。吸附-解吸分析仪。结果表明，ORCF 具有蓬松的多孔结构，并含有丰富的含氧基团。其孔隙表面有许多通孔，与二级大孔相连，形成分级大孔通道。同时，ORCF保持良好的体结构，在0.09 g cm ^-3的体密度下具有0.74 MPa的抗压强度。采用单变量法对孔雀石绿(MG)和Pb ²⁺进行批量吸附实验，研究不同初始条件对其吸附过程的影响。ORCF 对 MG 和 Pb ²⁺的最大吸附容量为587.68 mg g ^-1和 157.80 mg g ^-1分别具有 17.41 mg g ^-1 µM ^-1和 14.86 mg g ^-1 µM ^{-1 的}高分配系数。实验数据适用于朗缪尔等温线和伪二级动力学模型，对应于单层化学吸附。热力学分析表明吸附过程是自发吸热的。此外，ORCF对MG 和Pb ²⁺的去除率在5 个循环后仍可保持在90% 以上，表明ORCF 是一种高效的吸附剂，具有良好的吸附能力和循环稳定性。