Simultaneous tartrazine-tetracycline removal and hydrogen production in the hybrid electrocoagulation-photocatalytic process using g-C₃N₄/TiNTAs

This study aimed to investigate the removal of tartrazine dye & tetracycline antibiotic and hydrogen (H₂) production simultaneously through the hybrid electrocoagulation-photocatalytic process using g-C₃N₄/TiO₂ nanotube arrays (TiNTAs) nanocomposite. The g-C₃N₄/TiNTAs was used as the photocatalyst. The melamine as the precursor of g-C₃N₄ was varied to obtain the optimal loading on the removal of tartrazine dye & tetracycline antibiotic and hydrogen (H₂) production simultaneously. The integrated acrylic photoreactor was equipped with two 250-W mercury lamps. The nanotubular morphology of TiNTAs and nanostructure features of g-C₃N₄/TiNTAs were examined using FESEM/EDX and HR-TEM/SAED. The XRD patterns indicated the composition of TiNTAs, confirming the presence of anatase and rutile crystalline phases. UV-Vis DRS also showed a redshift in the composite absorbance and a reduced bandgap with g-C₃N₄ introduction. The results showed that when tartrazine and tetracycline were treated simultaneously, tartrazine was more dominantly degraded compared to tetracycline. In mixed pollutant system condition, the H₂ production increased by 17.0% and 41.1% compared to single pollutant system of tartrazine and tetracycline, respectively. The photocatalyst used in the hybrid process was the g-C₃N₄/TiNTAs (3 g) which provide the optimum H₂ production.