Seed-free synthesis of ZnO nanorods through egg white/glycerol medium for photocatalyst applications

Abstract

In this present work, zinc oxide nanorods (ZnO NRs) were synthesized using a simple, inexpensive, seed-free sol-gel method. Three different glycerol concentrations were used as coordinators for the morphologically controlled growth of ZnO NRs in the protein (egg white) medium. The impact of different glycerol concentrations on the structural and optical properties of nanostructures was investigated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV–vis) spectroscopy, photoluminescence (PL), and Brunauer–Emmett–Teller (BET) analyses. The obtained XRD patterns showed hexagonal wurtzite structures for ZnO NRs and exhibited a remarkable change along the (002) plane. The ZnO NRs related to the utilization of 2 mL glycerol exhibited the crystallite size of 53.12 nm, diameter size of about 55 nm, energy bandgap of 2.75 eV, and BET surface area (10.68 m2 g−1), which exhibited remarkably superior photoconductivity and photoluminescence at room temperature under sunlight irradiation in comparison to P25-TiO2 as criterion sample material. The enhancement of the photocatalytic performance is mainly attributed to the synergistic effects of mesoporous structure, increased surface area, reduced energy band gap, extended solar light utilization, and surface modification of ZnO NRs. This present work provides a simple, high-performance, and seed-free approach to the large-scale production of ZnO photocatalyst for water treatment applications.