Silver-doped molybdenum oxide ternary nanoparticles with excellent supercapacitor and hydrogen peroxide-sensing performance

Doped MoO3 is an electrocatalyst and an effective active material for supercapacitors. In this study, we achieved the synthesis of Ag/MoO3@graphene-like C3N4 (GL-C3N4) ternary nanoparticles via high-temperature calcination in N2 atmosphere using {Ag6Mo7O24}@Ag-MOF as the precursor. The synthesized material exhibited a high specific surface area with a primarily mesoporous structure, which facilitated rapid ion transfer due to the successful doping of GL-C3N4. Ag/MoO3@GL-C3N4 delivered a high specific capacitance of 3174.2 F g−1 at 1 A g−1 and remarkable cycling stability, with a retention rate of 91.06% after 5000 cycles. A fully symmetrical button battery, with nickel foam as the current collector, was fabricated based on Ag/MoO3@GL-C3N4. The battery delivered a high energy density of 28.1 W h kg−1 at a power density of 506.7 W kg−1. Finally, electrochemical sensors were fabricated based on Ag/MoO3@GL-C3N4 for the detection of H2O2. The sensors presented a linear detection range from 0.25 μM to 0.43 mM, with a detection limit of 0.64 μM. It is expected that the results of this study will open new avenues for the development of high-performance electrocatalysts and high-efficiency active materials for supercapacitors.