Synthesis of ZnO/Zn nano photocatalyst using modified polysaccharides for photodegradation of dyes

•Nano ZnO/Zn photocatalysts using modified polysaccharides by simple approach.•Effect of preparation conditions on final photodegradation of dyes.•A comparative study on various parameters.

A complete set of experiments in two aspects of studies combining the various factors affecting both the preparation and photocatalytic activity of ZnO/Zn nanocomposite obtained using corn starch and cellulose (native and modified) as chelating agents for the photodegradation of methylene blue, and congo red was carried out and discussed. The resulting ZnO/Zn nanoparticles obtained using modified polysaccharides exhibited super catalytic capability. The ZnO/Zn nanoparticles possessed favored surface area (11.8443–15.7100 m2/g) and pore size (12.3473–13.7453 nm). The photocatalytic degradation of nano ZnO/Zn was directly proportional to the surface area of nano ZnO/Zn. Regardless of the dye pollutants, nano ZnO/Zn obtained using modified corn starch showed enhanced catalytic activity than that of cellulose and methylene blue had comparatively faster degradation rate. Our findings shed light on the optimization of both preparation conditions of photocatalysts and their photocatalytic experimental conditions.