g-C3N4/TiO2 S-scheme heterojunction photocatalyst with enhanced photocatalytic Carbamazepine degradation and mineralization

• UVA light-driven g-C 3 N 4 /TiO 2 photocatalyst was successfully synthesized. • The photocatalytic Activity of g-C 3 N 4 /TiO 2 was evaluated with photodegradation of Carbamazepine (CBZ). • Keys factors influencing organic pollutants removal are optimized. • The kinetic of Carbamazepine removal was studied. In the present work, UVA light-driven g-C 3 N 4 /TiO 2 photocatalyst was synthesized for the photodegradation of Carbamazepine (CBZ) in aqueous medium. The morphological, the optical properties and the structure of the TiO 2 , g-C 3 N 4 and the prepared composites were analyzed using X-ray diffraction (XRD), Nitrogen adsorption–desorption isotherm based on BET, Raman Spectroscopy, Scanning Electron Microscopy (SEM) with EDX, UV–vis Diffuse Reflectance Spectroscopy (UV–vis DRS). Optical absorption studies revealed a 2.97 and 2.78 eV of band gap for the developed composites for 10%g-C 3 N 4 /TiO 2 (A10) and 30%g-C 3 N 4 /TiO 2 (A30), respectively. The N 2 adsorption–desorption isotherm showed an 80.64 and 59.67 m 2 /g of specific surface area for A10 and A30, respectively. Photodegradation studies show that A10 a composite photo-catalyst can eliminate 71.41% of CBZ with 30.38 % of mineralization yield within 360 min of UVA irradiation at optimum conditions (10 ppm of initial CBZ concentration and 0.1 g of 10%g-C 3 N 4 /TiO 2 loading). The kinetic results showed that the removal of this pollutant nearly followed a First-order kinetic model with a regression coefficient (R 2 ) values more than 0.98 and a high reaction rate constant recorded of 0.0034 min −1 for A10.