Preparation of nano-ZnO using solid state reaction and photocatalytic degradation kinetics of reactive black 5

Nano-ZnO powders were prepared through solid state method at room temperature, using Na2C2O4 and ZnSO4&middot7H2O as raw materials. Reactive black 5 (RB 5) was used as modeling pollutant decomposed by UV/ZnO. The results show that ZnO particle size was around 30nm. The photocatalytic process followed the pseudo first order kinetics and the optimum ZnO loading is 0.3g/L. The surface reaction rate constant (k0) and adsorption equilibrium (KZnO) of ZnO catalyst are 0.0163min-1 and 9.42L/g, respectively. UV/ZnO/H2O2 and UV/ZnO/Fenton process are not followed pseudo first order kinetics. A hyperbolic model can be established and suits for the UV/ZnO/H2O2 and UV/ZnO/Fenton process.