Sol–Gel Synthesis of Metal–Phenolic Coordination Spheres and Their Derived Carbon Composites

Abstract A formaldehyde‐assisted metal–ligand crosslinking strategy is used for the synthesis of metal–phenolic coordination spheres based on sol–gel chemistry. A range of mono‐metal (Co, Fe, Al, Ni, Cu, Zn, Ce), bi‐metal (Fe‐Co, Co‐Zn) and multi‐metal (Fe‐Co‐Ni‐Cu‐Zn) species can be incorporated into the frameworks of the colloidal spheres. The formation of coordination spheres involves the pre‐crosslinking of plant polyphenol (such as tannic acid) by formaldehyde in alkaline ethanol/water solvents, followed by the aggregation assembly of polyphenol oligomers via metal–ligand crosslinking. The coordination spheres can be used as sensors for the analysis of nucleic acid variants with single‐nucleotide discrimination, and a versatile precursor for electrode materials with high electrocatalytic performance.