Enhanced visible-light-driven photocatalytic performance of g-C3N4/BaTiO3 hybrids for efficient organic dye degradation

Abstract

Congo red (CR) dye, a known carcinogen present in wastewater, has been associated with bladder cancer, highlighting the urgent need for its effective and eco-friendly removal using non-toxic photocatalytic materials. This study investigates the structural, morphological, optical, elemental, specific surface area and visible-light-driven photocatalytic decolourizations of Congo red dye degradation behaviour of the g-C₃N₄/BaTiO₃ hybrids were characterized. X-ray diffraction result confirmed phase purity and crystal structure of g-C₃N₄, BaTiO₃, and g-C₃N₄/BaTiO₃ hybrids. Scanning electron and Transmission electron microscopy images revealed a sheet-like morphology, nearly spherical and mixed morphology of g-C₃N₄, BaTiO₃ and g-C₃N₄/BaTiO₃, respectively. Ultra-violet diffuse reflectance spectral result indicated a blue shift in the absorption edge and a reduced band gap, suggesting enhanced visible-light absorption for the hybrid materials. X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy results confirmed the element composition and oxidation states of C, N, Ba, Ti, and O elements. Brunauer–Emmett–Teller results revealed mesoporous structure of prepared samples. The g-C₃N₄/BaTiO₃ hybrids exhibited higher efficiency (85 % degradation at 90 min) and a higher rate constant (0.011 min⁻¹) under visible light. A potential degradation mechanism was proposed based on the surface area, pholuminescence, electronegativity and optical absorbance behavior. These results demonstrate that visible-light-active g-C₃N₄/BaTiO₃ hybrids photocatalysts are highly promising for the efficient removal of Congo red model dye, offering a sustainable approach to reduce its carcinogenic effects.