Preparation and characterization of Fe/TiO₂ in the presence of ionic liquid to optimize the photocatalytic degradation of acetaminophen using the response surface methodology

This work was aimed to prepare Fe doped TiO₂ on an ionic liquid template so that nanoparticles (IL-Fe/TiO_2(Ar)) could be formed to degrade acetaminophen (ACE) using the photocatalytic process. The synthesized nanoparticles were characterized using XRD, DRS, FTIR and FESEM–EDX. IL-Fe/TiO_2(Ar) enhanced ACE photodegradation using the response surface methodology based on central composite design. The results evidenced that the presence of the 1-octadecyl-3-methylimidazolium bromide template led to development of nanocrystals with a uniform, small grain size. Moreover, the band gap energy calculated for IL-Fe/TiO_2(Ar) was observed to be 1.6 eV. The ANOVA results of the photodegradation process revealed a second term model with an adjusted R² equal to 0.996. The results also showed an ACE removal efficiency of 90.35% under optimal conditions (IL-Fe/TiO_2(Ar) dosage = 0.63 g/L, pH 9 and UV irradiation time = 90.35 min). According to the findings, the pseudo first order model was introduced to study photodegradation kinetics. The findings also yielded insight into the most effective variables on degradation of ACE, which were time, IL-Fe/TiO_2(Ar) and pH, respectively. Moreover, IL-Fe/TiO_2(Ar) had high potential for the removal of ACE by photodegradation and proved to be an appropriate method to obtain optimum operating conditions.