Cobalt Oxide Nanoparticles Stabilized by d‑Glucose: Synthesis, Magnetic Properties and Catalytic Activity for...

Hybrid CoO₂@CoO nanoparticles were synthesized for the first time using d-glucose as a stabilizing agent. Their structural, morphological, vibrational, and magnetic properties were systematically studied using a wide range of techniques, such as Transmission Electron Microscopy (TEM, HR-TEM, EDS), X-ray Photoelectron Spectroscopy (XPS) and, DC and AC magnetic magnetization experiments (M-(T), M-(H), and χ-(T,f)). XPS data indicated high chemical stability, while magnetic measurements revealed that the hybrid material exhibited magnetic ordering below 8 K. The susceptibility peak showed a dependence on the excitation-field frequency, a feature commonly found in ensembles of small magnetic particles in the superparamagnetic regime. These nanoparticles were successfully used as catalysts for hydrogen generation via NaBH₄ hydrolysis. Their high catalytic activity sites were attributed to their well-distributed crystallites, which are responsible for the highly dispersed catalytic that promotes the hydrolysis of alkaline sodium borohydride solution. The hydrogen generation rate reached 1452.5 mL H₂ min^-1 g_cat ^-1 at room temperature (25-30 °C) and the apparent activation energy was calculated to be 51.73 kJ mol^-1.