Appendix.

In this work, firstly structural, optical, and morphological properties of Cobalt doped alpha phase iron oxide (hematite: Co-?-Fe2O3) thin films has been carried out. Secondly, Co-?-Fe2O3 and their applications in the area of wastewater treatment and antibacterial were tested. 0.25-1.5 and 2-20wt. % Co-?-Fe2O3 thin films have been deposited on 500ʻC heated glass via spray pyrolysis with moving nozzle (SPMN). For all 0.25-1.5wt. % Co-?-Fe2O3 thin films XRD analysis exhibit the presence of diffraction peaks corresponding to (012), (104), and (110), planes of ?Fe2O3 phase. The average grain size changes with doping concentration, it reaches 38.81nm for 1.5 wt. % Co doping. FTIR study confirms the existence of Fe-O bonds of ?-Fe2O3, with enhanced hydroxyl radical OH on the surface of Fe2O3. Such hydroxyl radical OH is a good result for Photocatalytic application. Photocatalytic activities of 0.25-1.5wt. % Co-?-Fe2O3 samples were studied based on the degradation of methylene blue (MB). This activity increases with cobalt doping concentration, and it is better under sunlight irradiation. For antibacterial test, the doping concentration was varied from 2 to 20wt. %. Analyzing XRD pattern indicated the presence of diffraction peaks corresponding to plans (012), (104), (110), (113), (024), (116), (214), and (300) which signified the hematite phase formation. As a result of doping, two added peaks were appeared and much well with (200) and (311) planes, of Cobalt oxides CoO and Co3O4, respectively. The peak positions correspond to hematite marked a fixed slight shift to lower 2? values. Crystalline size increases in the beginning of doping then decreases with doping concentration. SEM images demonstrate that the clusters of grain size are homogeneous with some agglomerating sites. The average grain sizes clusters are: 166, 200, 227, and 225 nm for 2, 5, 10, and 20wt. %, respectively. The synthesized cobalt doped hematite nanoparticles exhibit an antibacterial activity against E. coli, Listeria innocua, Pseudo mona saeruginosa and Salmonella enteric beyond 5wt. % Co/Fe doping.