LAUSR

Nowadays, tremendous increase in environmental issue is an alarming threat to the ecosystem. Influence of pH is the major concern for the application of ZnO nanoparticles. These nanoparticles with different tuning defects were prepared by simple combustion method using Zn nitrate as precursor and glucose as fuel and oxidizer. This paper reports the effect of four different pH values 5, 7, 9 and 11 to synthesize ZnO nanoparticles namely PZ1-PZ4. Prepared samples were characterized by several techniques including XRD, FESEM, FTIR, UV Vis, PL, LCR and Raman spectroscopy. These detailed characterization study confirmed that the prepared ZnO nanoparticles are possessing well crystalline and hexagonal wurtzite structure. Interestingly, it was observed that influence of pH greatly effects on morphological and electrical properties. The average grain size is in the range of 40–80nm. Raman spectroscopy exhibited a sharp and strong mode near 487 cm−1 which further confirmed the well crystalline and hexagonal wurtzite structure. Furthermore, ZnO as photocatalyst exhibited photocatalytic degradation towards direct red (DR-31) dye. From the photocatalytic experiment it was observed that degradation percentage increases with increasing pH value up to 9 and thereafter percentage degradation was decreased. Thus an ideal pH value of prepared nanoparticles is pH-9 exhibiting almost completes degradation only in 75 min under UV irradiation. Kinetic studied revealed that all the samples follows first order rate constant and for pH-9 rate constant is 0.04075 min−1.