A high performance supercapacitor based on decoration of MoS2/reduced graphene oxide with NiO nanoparticles

In this report, the capacitive performance of molybdenum disulfide (MoS2) and reduced graphene oxide (rGO) supercapacitors and the effect of NiO nanoparticle incorporation is investigated. A comparison between rGO, MoS2, and MoS2/rGO sheets revealed that the MoS2/rGO composite exhibited higher capacitance owing to better charge transfer in comparison to its individual counterparts. The incorporation of NiO nanoparticles was feasible through sputter deposition of 10 nm NiO film, which upon thermal annealing converted into nanostructures with an average grain size of 35 nm. The NiO-decorated MoS2/rGO electrode showed superior capacitance performance compared to non-decorated samples. The thermal treatment of NiO film was performed at 350 °C in the presence of argon gas for 30 min. The final capacitance of the a:NiO/rGO and a:NiO/MoS2/rGO electrodes was significantly enhanced to 4.8 and 7.38 mF cm−2, respectively, compared with individual rGO (2.31 mF cm−2) or MoS2 (1.01 mF cm−2) electrodes at the same scan rate of 25 mV s−1. Moreover, the a:NiO/MoS2/rGO electrode exhibited a long discharging time of 34.5 s with promising cycle stability (about 90%) over 1000 cycles.