Influence of solvent on solvothermal fabrication of BixOyIz nanophotocatalyst over Zn-Fe spinel for comparative demineralization of orange II and methylene blue under simulated solar light illumination

Novel p-n type BixOyIz/ZnFe2O4 nanoheterojunction was prepared in various solvents via two step solvothermal-precipitation route. The influence of solvent on physicochemical and optical properties of samples were investigated by FESEM, XRD, TEM, FTIR, EDX, pHpzc, BET and, UV-Vis DRS techniques. The results indicate that different solvents lead to distictive physicochemical properties. The results revealed that ethanol mediated samples possess superior performance than ethylene glycol, methanol and, water mediated samples. This is ascribed to band position of nanophotocatalysts as Bi7O9I3/ZnFe2O4 and BiOI/ZnFe2O4 are type I and type II heterojunction structures, respectively. The type II heterojunction is the most effective architecture for the semiconductor heterojunctions. The photocatalytic performance of BixOyIz/ZnFe2O4 is tested under simulated sunlight irradiation via elimination of acid orange 7 and methylene blue. Furthermore, the photocatalytic mechanism of degradation was proposed for the both heterojunctions. The effect of catalyst dosage, dye concentration and pH were also investigated.

Automated summary

In this study, p-n type BixOyIz/ZnFe2O4 nanoheterojunction was prepared using a two-step solvothermal-precipitation route in different solvents. The influence of solvent on the physicochemical and optical properties of the samples was investigated. The results showed that samples mediated by ethanol exhibited superior performance compared to those mediated by ethylene glycol, methanol, and water. This can be attributed to the band position of the nanophotocatalysts, with Bi7O9I3/ZnFe2O4 and BiOI/ZnFe2O4 exhibiting type I and type II heterojunction structures, respectively.