Kans biomass inspired fabrication of Ni_0.5Co_0.5Fe₂O (spinel structure) nanocatayst and its application in single pot cellulosic biohydrogen production via fermentation route

Sustainable one-pot method for producing sequential biohydrogen from lignocellulosic waste using nanocatalyst has been reported. Approach of sustainable fabrication of Ni_0.5Co_0.5Fe₂O₄ (spinel structure) nanocatalyst has been adopted and performed following the method of sol-gel using kans grass biomass. Further, characterization studied using techniques like XRD, followed by FT-IR, and Raman along with UV–Vis spectroscopy as well as SEM BET, and XPS have been conducted. Newly synthesized nanocatalyst applied in the solid-state fermentation for enzyme production using kans biomass at different concentrations. Optimized concentration of 10 mg nanocatalyst, 26 IU/gds (International unit per gram of dry substrate), FP and 74 IU/gds BGL produced in 72 h of time incubation, whereas 98 IU/gds EG was recorded in 48 h. The raw enzyme was thermally stable at 60°C, with half-life up to 25 h, and in bioconversion of kans grass biomass substrate, the same enzyme produced maximum 42.0 g/L fermentable glucose in 24 h. Further, the sugar hydrolyzate was set for sequential biohydrogen production followed by dark and photo fermentation and collectively produced cumulative H₂ 2837 ml/L in eleven days with a final fermentation pH of 4.0.