NaBH4 Hydrolysis over Silver Nanoparticles Synthesized via Combustion Route

Solution combustion synthesis (SCS) is a powerful route for synthesizing a wide range of nanostructures. The fine adjustment of the experimental parameters (fuel type, fuel/oxidizer ratio, pretreatment temperature, etc.) plays a crucial role in controlling the structural as well as the textural features of the resulting nanomaterial. In this study, we investigate the synthesis of silver nanoparticles (Ag NPs) using the combustion method with glycine as a fuel. The calcination of the silver nitrate/glycine precursor was performed over a temperature range of 150–600°C. The obtained Ag NPs were characterized by XRD, FTIR, TEM, and XPS techniques. XRD diffraction patterns revealed that the development of Ag NPs started at 150°C. FTIR spectroscopy confirmed the presence of various functional groups in the calcined samples. TEM images revealed that increasing the temperature from 200 to 600°C resulted in a morphology change from accumulated spheres into inter-welded capsules. XPS analysis detected Ag, O, and C at the surface of the prepared Ag NPs. NaBH4 hydrolysis, at the temperature range of 30–50°C, was chosen for evaluating the activity of the prepared Ag NPs. It was found that the activity increased with increasing reaction temperature, with the optimal activity exhibited by the sample calcined at 400°C. The investigation was extended to check the effect of various parameters including NaBH4 weight, alkalinity, and recycling on the activity of the optimal catalyst.