Preparation of flexible composite electrode with bacterial cellulose (BC)-derived carbon aerogel supported low loaded NiS for methanol electrocatalytic oxidation

In this study, carbon aerogel (CA) were obtained by inexpensive bacterial cellulose (BC) hydrogel freeze-dried and carbonized under N2 atmosphere. Then nickel sulfide (NiS)/CA composite aerogel electrodes with different contents were successfully prepared by a one-step solvothermal method. The morphology, phases and surface electronic state of these electrodes were characterized by SEM/TEM, XRD and XPS, respectively, and their electrocatalytical properties for methanol oxidation were investigated by cyclic voltammetry (CV) in the alkaline media of methanol. The NiS particles dispersed uniformly on CA, and the obtained material maintained the reticulated porous structure of BC. The methanol oxidation peak current density of CNS-0.5 at 0.8 V reached 43 mA/cm2 (263 mA/mg). After 1000 cycles, the peak current density retained 92% of the initial state. The composite electrode has good catalytic activity and good cycle performance for methanol catalysis. Nickel sulfide with high crystallinity transforms to nickel oxide with low crystallinity after a long cycle test, which results in excellent cycle performance of the composite. NiS/CA electrodes have the potential for application in portable or wearable devices.