Plant polyphenol-derived ordered mesoporous carbon materials via metal ion cross-linking

Critical assessment of plant polyphenols (ferulic acid, quercetin, caffeic acid, gallic acid, arbutin, proanthocyanide) that can be used for forming ordered mesoporous carbons (OMCs) via metal ion (Fe, Co, Ni, Zn, Zr, Mg, Ce, La) and bimetal ion (MgFe, CoNi) cross-linking chemistry is reported. In the methodology, coordination interactions between aromatic hydroxyl groups of polyphenol molecules and metal ion cross-linkers initiate OMC formation via ethanol evaporation induced self-assembly (EISA). Aromatic hydroxyl content, solubility in the evaporating solvent and low to moderate molecular mass are key factors in selecting plant polyphenols for OMC formation. The as-prepared metal-functionalized OMCs were applied to electrocatalytic reduction of nitrate to nitrogen (conversion 85.5%, nitrogen selectivity 99.8%), catalytic hydrogenation of furfural to tetrahydrofurfuryl alcohol (conversion 100%, tetrahydrofurfuryl alcohol selectivity 100%), and electrode materials for supercapacitors (specific capacitance, 222 F/g at 0.5 A/g). Using the proposed techniques, a wide range plant polyphenols can be used to form OMCs that are directly applicable to environmental applications after carbonization in a nitrogen atmosphere without further post-processing, doping or modification.