Degradation of methylene blue-ciprofloxacin and hydrogen production simultaneously using combination of electrocoagulation and photocatalytic process with Fe-TiNTAs

The study reported in this paper combines the electrocoagulation and photocatalysis for the simultaneous degradation of methylene blue dyes (MB)-antibiotic ciprofloxacin (CP) and production of hydrogen. The pollutant removal process was conducted by combining adsorption by electrocoagulation and degradation by photocatalysis. Meanwhile, H₂ was produced by reducing the H⁺ on the cathode and the photocatalyst surface in a reactor made of acrylic equipped with aluminum as the anode, stainless steel 316 plates as a cathode, Fe-doped titania nanotube arrays (TiNTAs) as a photocatalyst, and a 250-W mercury lamp as the light source. TiNTAs were synthesized via anodization and followed by the successive ionic layer adsorption and reaction (SILAR) method to incorporate Fe as the dopant. In particular, the effects of Fe loading in the composite photocatalyst are investigated. XRD results showed that TiO₂ nanotubes arrays comprise a 100% anatase phase. FESEM, EDX, TEM, and HRTEM analysis confirmed the formation of the nanotubular structure of TiO₂ and the presence of Fe deposited on the surface. The UV–Vis DRS indicated that the bandgap of Fe-TiNTAs reduced with Fe introduction, as compared to that of the undoped TiNTAs. The results showed that accumulation of the produced hydrogen from the combination of electrocoagulation-photocatalytic system is greater than that which is obtained using individual electrocoagulation or photocatalytic system. The combined process exhibited an enhanced degradation ability of methylene blue and ciprofloxacin, as well as in the H₂ production.