Fig. 3From: Optimization of metal dopant effect on ZnO nanoparticles for enhanced visible LED photocatalytic degradation of citalopram: comparative study and application to pharmaceutical cleaning validationNitrogen adsorption–desorption isotherms (a) undoped ZnO (b) Mg/ZnO (c) Cu/ZnO (d) Sn/ZnOBack to article page