Heteroatoms doped yolk-shell hierarchically porous carbon derived from ZIF-8 for electrochemical sensing

In this work, we proposed a facile chemical etching/pyrolysis strategy to prepare multi-heteroatoms doped yolk-shell porous carbon by using common ZIF-8 as the precursor and phytic acid as the etching agent. The as-prepared porous carbon was composed by N-doped carbon frame core (N-CF) and N, P-codoped carbon frame shell (N, P-CF) with unique hierarchically porous structure. Besides, the yolk-shell hierarchically porous carbon (N-CF@N, P-CF) exhibited large specific surface and pore volume, promoted electrochemical active area and electron transfer kinetics. Compared with pure ZIF-8 derived N-CF, the as-synthesized N-CF@N, P-CF displayed enhanced electrochemical activity toward the oxidation of various target analytes, including organic pollutants (hydroquinone and catechol), active pharmaceutical molecule (acetaminophen), and small biological molecules (dopamine and uric acid). As a result, a versatile electrochemical sensing platform was successfully developed for the sensing of hydroquinone, catechol, acetaminophen, dopamine and uric acid with high sensitivity and selectivity. Besides, the detection limits were evaluated as 15.4 nM, 18.8 nM, 16.2 nM, 22.2 nM and 24.5 nM, respectively, which were competitive with many other electrode materials. This work helps to prosper the type of carbon-based nanostructure, and provides an advanced electrode material with great application potential for electrochemical sensors design.