Eco-friendly nanocatalysts for hydrogen generation via sodium borohydride hydrolysis and enhanced fuel cell applications

Sodium borohydride (NaBH₄) hydrolysis is a promising method for sustainable hydrogen production, but its efficiency depends on high-performance and eco-friendly catalysts. This study introduces a green hydrothermal synthesis using tobacco stem extract to fabricate Co–Sb nanoparticles, reducing toxic chemical usage compared to conventional methods. Catalytic tests confirm their high efficiency in NaBH₄ hydrolysis, with hydrogen generation increasing at higher temperatures and NaOH/NaBH₄ concentrations. Structural analyses (XRD, FT-IR, SEM, TEM) reveal an amorphous, porous morphology with spherical particles (∼20–30 nm). Co–Sb nanoparticles achieve a hydrogen generation rate of 5618 mlmin⁻¹g⁻¹, surpassing Co nanoparticles (5360 mlmin⁻¹g⁻¹), with lower activation energy (30.9 kJ mol⁻¹ vs. 35.5 kJ mol⁻¹), highlighting Co–Sb's superior catalytic efficiency—additionally, 1 wt% Sb doping enhances hydrogen production and improves PEM fuel cell performance, reaching a peak power density of 137.3 mW/cm². However, reusability tests of the Co–Sb catalyst revealed a decline in the hydrogen generation rate, indicating catalyst deactivation due to oxidation on active surfaces and the accumulation of by-products. Furthermore, excessive Sb doping was found to block active sites on the catalyst surface, thereby reducing its efficiency. This study underscores the viability of green-synthesized Co–Sb nanoparticles for hydrogen generation and fuel cell applications, offering a sustainable alternative to energy technologies.