Ammonium Persulfate Derived N,S-Dual-Doped Graphene─A Versatile Bifunctional Electrode for Electrochemical Energy Storage and Sensing

Bifunctional properties of nanomaterials are currently more focused as well as advantageous in various domains of electrochemistry. The supercapacitor analyses show that the N,S dual-doped graphene derived from ammonium persulfate (APS) and graphene oxide (GO) in a weight ratio of 1:1 delivered an increased gravimetric capacitance of 393 F g–1 in 1 M H2SO4 solution at 0.5 A g–1. The full-cell investigations revealed that the symmetric APSGO-1 cell in 0.01 M KI/1 M H2SO4 attained the energy density of 24 W h kg–1 at 2 A g–1 along with 92% retention from its initial capacitance over 10,000 cycles. The glassy carbon electrodes modified with APSGO (APSGO/GCE) were investigated for electrochemical sensing of dihydroxybenzene isomers, specifically hydroquinone (HQ) and resorcinol (RS). The material demonstrated the ability to simultaneously sense both isomers, displaying well-defined peaks and an adequate potential difference between them. Sensing analysis revealed that APSGO1/GCE exhibited superior performance, achieving low detection limits of 0.1 and 0.2 μM in the linear range from 0.3 to 200.0 μM for HQ and RS, respectively, in 0.1 M PBS (pH 7.0). The practical applicability of the APSGO1/GCE sensor was successfully demonstrated in tap water samples, yielding promising results.