Nanoporous carbon spheres derived from metal-phenolic coordination polymers for supercapacitor and biosensor.

The conversion of plant polyphenol to multi-functional nanoporous carbon spheres (NCSs) is desirable and challenging. Tannic acid (TA), as one kind of plant polyphenol, has been regarded as one of potential renewable carbon sources for nanoporous carbon materials. However, the nanoporous carbon materials derived from TA usually show low surface area and irregular morphology, which partially limit their broad applications. Herein, we demonstrate the successful synthesis of NCSs with high surface area (up to 2221 m/g) and uniform diameter (∼120 nm) by direct carbonization of zinc-phenolic coordination polymer using TA as a carbon source. The zinc contents play an important role in tailoring the porosity of NCSs. The specific surface area of NCSs can be adjusted in the range of 527-2221 m/g as the zinc contents in the coordination polymers changed from 0 to 8.6 wt%. To verify the multi-functions of NCSs, such carbon spheres are further used as a sensing platform for the analysis of nucleic acid variants with high selectivity and low limit of detection, and electrode material for supercapacitor with high specific capacitance, good capacitance retention, and excellent cyclic stability.