Exploiting Pr0.66(MoO4)-rGO nanocomposite for effective energy storage and electrochemical sensing applications

Abstract

The multi-functional composites derived from rare-earth-based materials offer favorable properties for numerous applications. Given this, here we explore the energy storage and the sensing application of praseodymium molybdate-reduced graphene oxide [Pr0.66(MoO4)-rGO] nanocomposite for silibinin (SIL) for the first time. The [Pr0.66(MoO4)-rGO] composite was prepared hydrothermally and examined by XRD, SEM with EDX, FT-IR, AFM, particle size analyzer, zeta potential, and thermal methods. Detailed electrochemical properties of the Pr0.66(MoO4)-rGO nanocomposite over nickel foam (NF) were explored for energy storage applications. As a supercapacitor, the Pr0.66(MoO4)-rGO/NF electrode exhibited an impressive specific discharge capacitance value of 684.25 F g−1 with significant cycle stability of over 2000 cycles. Furthermore, Pr0.66(MoO4)-rGO/glassy carbon electrode (GCE) was fabricated for the electrochemical sensing of an anticancer drug, SIL, employed to treat a wide range of cancers. The peak current of SIL was enhanced by 38 – folds at Pr0.66(MoO4)-rGO/GCE compared to that at bare GCE. The effect of pH, scan rate, accumulation time and amount of suspension of Pr0.66(MoO4)-rGO on the electrochemical behavior of SIL was studied. SIL exhibited well-defined peaks in phosphate buffer of pH 3.0. Linearity between the peak current and concentration of SIL was noticed in the range of 2.04–44.89 μM for square wave voltammetric and 3.0–50 μM for differential pulse voltammetric methods. The developed methods were successfully applied for the determination of SIL in pharmaceutical formulations and biological samples. The accuracy and precision of the developed electrochemical methods were evident by higher percentage recovery and lower relative standard deviation (RSD) values.