Abstract The voltammetric responses of novel porous Co3O4 spinel materials supported on MOF-derived carbons (MOFDC) have been described. The electrocatalysts were prepared using microwave-assisted hydrothermal methods, obtaining both Rich- and Starved-Co3O4 MOF-derived carbons (i.e., R-Co3O4@MOFDC and S-Co3O4@MOFDC). The physicochemical properties of the porous electrode materials were thoroughly characterized via XRD, SEM, BET, EDX and XPS. The R-Co3O4@MOFDC shows low specific surface area and small pore volume, while the S-Co3O4@MOFDC is characterized with high specific surface area and large pore volume, about four times larger than the former. Using dopamine as a model analyte, the study shows the voltammetric response towards the detection of dopamine detection to be strongly dependent on the diffusive and adsorptive/capacitive modes: R-Co3O4@MOFDC exhibits high diffusive mode with enhanced dopamine detection, while S-Co3O4@MOFDC exhibits high adsorptive mode and relatively poor dopamine detection. The overall voltammetric response is interpreted in terms of fast semi-infinite planar diffusion of dopamine towards the electrode surface and the inhibition of the thin layer diffusion process due to the depletion of the electrolyte trapped within pores (leading to disadvantageous adsorption). At higher concentrations (DA > 3 mM) the adsorption behaviour at these porous electrode follows the Langmuir adsorption isotherm with adsorption equilibrium constant (β) of (1.96 ± 0.16) × 105 and (2.53 ± 0.20) × 105 M−1 for R-Co3O4@MOFDC and S-Co3O4@MOFDC, respectively. This study opens doors for rational design and development of transition metal-based MOFDC for the detection of biomolecules.

中文翻译：

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MOF 衍生碳支持的多孔 Co3O4 尖晶石的伏安响应：多孔体积对多巴胺扩散过程的影响

摘要 描述了负载在 MOF 衍生碳 (MOFDC) 上的新型多孔 Co3O4 尖晶石材料的伏安响应。电催化剂是使用微波辅助水热法制备的，获得了富 Co3O4 MOF 衍生的碳（即 R-Co3O4@MOFDC 和 S-Co3O4@MOFDC）。通过XRD、SEM、BET、EDX和XPS对多孔电极材料的理化性质进行了彻底的表征。R-Co3O4@MOFDC 具有低比表面积和小孔体积的特点，而 S-Co3O4@MOFDC 具有高比表面积和大孔体积的特点，约为前者的 4 倍。该研究使用多巴胺作为模型分析物，表明对多巴胺检测的伏安响应强烈依赖于扩散和吸附/电容模式：R-Co3O4@MOFDC 表现出高扩散模式和增强的多巴胺检测，而 S-Co3O4@MOFDC 表现出高吸附模式和相对较差的多巴胺检测。整体伏安响应被解释为多巴胺向电极表面的快速半无限平面扩散和由于被困在孔隙内的电解质耗尽（导致不利吸附）而抑制薄层扩散过程。在较高浓度 (DA > 3 mM) 下，这些多孔电极的吸附行为遵循 Langmuir 吸附等温线，吸附平衡常数 (β) 为 (1.96 ± 0.16) × 105 和 (2.53 ± 0.20) × 105 M-1，R-分别为 Co3O4@MOFDC 和 S-Co3O4@MOFDC。