Electro-crystallized SnO2 nanoparticles for river-water heavy-metal ion pollutant removal process

SnO2 nanoparticles were electro-crystallized in an electrochemical cell containing two tin electrodes, and an electrolyte solution of C4H12Cl and the effect of growth conditions has been studied on their structural properties. The XRD patterns confirmed the formation of tetragonal tin dioxide at 700 °C. SEM images showed the mean particle size ranges from 12 to 35 nm, depending on growth conditions. The particles synthesized at 25 V, 55 °C, and 0.004 M with mean size of about 12 nm are the smallest particles. The band gap of SnO2 nanoparticles is found to be 4.2 eV. The removal of cobalt and cadmium from laboratory water and Seimareh and Karoon rivers in Iran has been investigated. The results showed that in the optimal removal conditions; 10 V, pH of 13, initial heavy metals’ concentration of 100 mg/L and reaction time of 30 and 50 min, the removal efficiency of cadmium and cobalt is 100% and 99.95%, respectively.