Due to their tremendous industrial, environmental, and biological applications, research focusing on the synthesis and applications of silver nanoparticles (Ag NPs) has attracted increased interest from researchers over the past two decades. Their structural as well as textural properties can be easily tuned depending on the synthesis protocol utilized. Combustion synthesis has received increased attention as a one-pot route for the synthesis of a wide spectrum of nanomaterials. In this study, we present the results of synthesizing Ag NPs employing urea as a combustion fuel. The effect of the temperature of calcination on the formation and structural features of Ag NPs has been checked over the 400–700 °C temperature range. The characterization of the synthesized Ag NPs has been performed using XRD, SEM, TEM, and XPS techniques. It was found that Ag NPs, with a crystallite size of 40 nm, start to form at around 400 °C. Conducting the calcination at the 500–700 °C range results in the persistence of the obtained Ag NPs. Moreover, the obtained nanomaterials are characterized by a membrane-like morphology. The activity performance of the synthesized Ag NPs was examined for the hydrolysisof sodium borohydride (NaBH4) over a temperature range of 35–50 °C. Increasing the calcination temperature has led to a decrease in the activity of the Ag NPs during the NaBH4 hydrolysis.