Investigation on the effect of dopant agents an‎d graphene oxide (GO) on the photocatalytic properties of ZnO nanoparticles

9/13/2025 12:00:00 AM

Photocatalytic degradation of resistant compounds by semiconductors represents an environmentally friendly an‎d cost-effective approach due to their ability to function under various reaction conditions. Among different photocatalysts, zinc oxide (ZnO) has attracted considerable attention owing to its wide ban‎d gap an‎d high electron mobility. However, its photocatalytic performance is limited by the rapid recombination of charge carriers an‎d its limited absorption in the visible light range. Various strategies, such as doping an‎d heterojunction formation, have been explored to overcome these limitations. In this study, to improve the photocatalytic performance of ZnO nanoparticles, a series of optimization approaches were investigated, including the choice of solvent an‎d additives in the synthesis process, doping with alkaline earth metal ions (Ca an‎d Sr), an‎d compositing with graphene oxide (GO). First, the effect of solvent type (ethanol, propanol, an‎d 1,4-butanediol) an‎d polymeric additives on the structure, crystallite size, morphology, an‎d surface properties of the samples was examined. Subsequently, the base ZnO sample was doped with 3 mol% of Ca, Sr, an‎d a co-doped combination of both (Zn-3Ca, Zn-3Sr, Zn-3Ca-3Sr). XRD an‎d FTIR data confirmed the incorporation of dopants into the ZnO lattice an‎d the induction of lattice strain. The ban‎d gap energy decreased from 3.17 eV in the pure ZnO sample to 2.83 eV in the co-doped sample, an‎d the PL intensity significantly dro‎pped, indicating reduced electron-hole recombination. In the final stage, the Zn-3Ca-3Sr sample was composited with 5, 10, an‎d 15 wt% GO. XRD, SEM, BET, an‎d FTIR results showed that the addition of GO improved particle distribution, increased specific surface area (from 17.66 m²/g in the co-doped sample to 21.75 m²/g in the 15% GO sample), an‎d enhanced surface an‎d electronic properties. The ban‎d gap of the sample containing 10% GO reached its minimum value of 2.51 eV, an‎d the highest photocatalytic degradation rate was observed for the Zn-3Ca-3Sr/15%GO sample with a rate constant of k = 0.120 min⁻¹, approximately three times higher than the base sample. Overall, the results demonstrated that the combined strategy of doping an‎d compositing is an effective approach for optimizing the structure an‎d photocatalytic performance of ZnO, with Zn-3Ca-3Sr/10%GO being identified as the final optimal sample.

فوتوكاتاليست , اكسيد روي , آلايش , كامپوزيت , اكسيد گرافن

Photocatalyst , Zinc oxide , Doping , Composite , Graphene oxide

mohammad tashakkori masouleh

Masood Hasheminiasari