Enhanced reactivity of copper nanoparticles mass-produced by reductive precipitation in a rotating packed bed with blade packings

This investigation concerns the mass-production of copper nanoparticles by reductive precipitation with a CuSO4 concentration of 0.1 mol/L and an NaBH4 concentration of 0.2 mol/L in a rotating packed bed (RPB) with blade packings. Copper nanoparticles that were mass-produced at 25°C, a rotational speed of 900 rpm, and flow rates of aqueous CuSO4 and NaBH4 of 0.9 L/min exhibited an average crystallite size of 15 nm and a mean particle size of 87 nm. A rate of mass-production of copper nanoparticles of 9 kg/day was obtained using the RPB with blade packings with reductive precipitation. The degradation of Reactive Red 2 (RR2) with dissolved oxygen was used to evaluate the reactivity of the mass-produced copper nanoparticles. At 30°C and pH 4, the efficiency of the degradation of RR2 (10 mg/L) using the mass-produced copper nanoparticles at a dosage of 0.3 g/L for 5 min was about 79%, which was much higher than the 26% that was achieved using copper nanoparticles that were obtained from Sigma-Aldrich. The experimental results herein reveal that the mass-produced copper nanoparticles have excellent potential in degrading dyes in water.