Akademik Veri Yönetim Sistemi
Electrochimica Acta, cilt.526, 2025 (SCI-Expanded)
NiS is a promising supercapacitor electrode with its high electrical conductivity, mechanical/thermal durability, and high theoretical specific capacitance. However, stacking issues arising from the fabrication of NiS electrodes from hydrothermally synthesized NiS nanoparticles limit the device performance. In this study, NiS electrodes were grown directly onto Ni-foam by hydrothermal method and, unlike the literature, the role of short hydrothermal reaction time (15–45 min) on the supercapacitor properties was investigated. FESEM and XRD analyses showed that NiS-15 min had a porous surface consisting of nanosheets (pore size <50 nm) and a high purity hexagonal NiS phase free from other Ni-S secondary phases. As the hydrothermal reaction time decreased, gravimetric and areal specific capacitances increased. NiS-15 min provided specific capacitance at record levels according to the literature (5172 Fg-1 at 2 Ag-1, 4250 Fg-1 at 20 mVs-1, 1.47 Fcm-2 at 1 mAcm-2) and retained 50 % of the initial capacity even at a high current density of 200 Ag-1. Besides, for NiS-15 min, surface capacitive contributions were determined as 35 % and 12 % in oxidation and reduction processes at 1 mVs-1. As a result, porous NiS-nanoleafs having significantly improved charge storage capacity via surface capacitance and pseudocapacitive mechanisms are suitable electrodes for energy storage devices.