Development of livestock poultry waste based Ni-Co/S green nanocomposite catalysts: a facile one-pot in situ solvothermal method for alkaline methanol oxidation and super capacitor applications

The varying molar ratios of nickel-cobalt/sulphide nanoparticles coated on bio-carbon (Ni1.5Co0.5S/C, Ni1Co1S/C and Ni0.5Co1.5S/C), nickel-chalcogenide/bio-carbon (NiS/C) and cobalt-chalcogenide/bio-carbon (CoS/C) have been prepared though a facile single-step in situ solvothermal route using livestock poultry waste chicken feathers as sources for bio-carbon and bio-sulphur. The catalysts developed were characterized using different analytical techniques, viz., X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDAX) and cyclic voltammetry. The results obtained from the electrochemical characterization studies, it was inferred that the Ni1Co1S/C nanocatalyst possesses the higher methanol (0.5 M) oxidation current density in 0.5 M KOH with minimum onset potential when compared to that of other green composite catalysts, Ni1.5Co0.5S/C, Ni0.5Co1.5S/C and NiS/C developed in the present work. Further, the green nanocomposite Ni1Co1S/C synthesized was subjected to different studies in order to assess and ascertain its super capacitor characteristics. The results confirmed that the green nanocatalyst Ni1Co1S/C possesses the maximum value of specific capacitance of 785 F g(-1) at a current density of 1 A g(-1) in 3.0 M KOH solution. The enhanced performance of Ni1Co1S/C catalyst developed in the present work makes it suitable for the power generation and storage application, in addition to have an advantage of value added product of bio-carbon and sulphur derived from sustainable and renewable resource of livestock poultry waste. The present work is also considered as the first attempt to develop green nanocomposite Ni-Co sulphide/C electrocatalysts through a facile and cost-effective method and can be used for the development of direct methanol fuel cells (DMFCs) and super capacitor device design applications.