Promotional Synergistic Effect of Cs–Au NPs on the Performance of Cs–Au/MgFe2O4 Catalysts in Catalysis 3,4-Dihydropyrimidin-2(1H)-Ones and Degradation of RhB Dye

The recent paper deals with the immobilization of hybrid gold–cesium nanoparticles (Au–Cs NPs) onto magnesium ferrites (MgFe 2 O 4 ) surface, and then the prepared composites were characterized by several techniques such as XRD, TEM, SEM, FTIR, UV–Vis diffuse reflectance spectroscopy (DRS), thermal TGA analysis, and N 2 adsorption–desorption. It was found that the MgFe 2 O 4 structure was retained after loading of Au–Cs NPs, and the surface area increased, but the pore diameter decreased that may be due to the deposition of Au–Cs NPs on MgFe 2 O 4 that cause pore blockage. Also, the catalytic performance toward the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and photocatalytic degradation of Rhodamine B dye (10 ppm/100 ml), under a Hg lamp (150 W) as a simulated source of sun-light were investigated by changing various parameters such as Au–Cs content, catalyst weight, reaction time, and the recycling of the catalyst. The catalytic performance of 3,4-dihydropyrimidin-2(1H)-ones over 3.0 wt% Au–Cs/MgFe 2 O 4 nanocomposite (NC) was reached to 99.0% after 2 h. Also, the results showed that the photocatalytic activity of Au–Cs/MgFe 2 O 4 nanocomposite (NC) increases with the modification of MgFe 2 O 4 by changing the content from 1.0 to 5.0 wt% Au–Cs NPs, the sample of 3.0 wt% Au–Cs/MgFe 2 O 4 nanocomposite showed the higher photocatalytic activity. The catalyst is found to be reusable.