Efficient hydrogen evolution from NaBH4 using bimetallic nanoparticles (Ni–Co) supported on recycled Zn–C battery electrolyte paste

Abstract

Electrolytic paste (EP) from used batteries was innovatively utilized as a support for Ni–Co nanoparticles (Ni–Co NPs) to catalyze hydrogen evolution from NaBH4. The materials exhibited a porous and heterogeneous morphology, characterized by a ZnMn2O4 interplanar distance of 0.34 nm, as confirmed by SAED analysis. Elemental analysis identified carbon, nitrogen, hydrogen, and sulfur, while ICP-MS quantified zinc, manganese, and iron. XRD unveiled an amorphous broad peak at 2θ = 13.3–39.8°, with additional phases identified as ZnO, graphite, simonkolleite, manganese oxides, and hetaerolite. Raman spectroscopy showcased characteristic bands typical of carbonaceous materials. FTIR detected functional groups alongside Ni–O, Co–O, and Zn–O bonds. Various Ni/Co ratios were assessed, and the 25:75 and 20:80 (w/w) ratios showed optimal performance, yielding hydrogen at rates of 238.1 and 278.0 mL H2 gcatalyst−1 min−1, respectively. The determined activation energy was 32.76 kJ mol−1. The turnover frequency reached 1823.93 mL H2 gcatalyst−1 min−1 (328.15 K), and the catalyst exhibited satisfactory performance over 16 reuse cycles.