Rod-like borocarbonitride/Ce2(WO4)3 heterojunctions: Experimental and DFT investigation of photocatalytic performance

This study explores the surface-engineered heterojunction formed between cerium tungstate (Ce2(WO4)3) and rod-like borocarbonitride (BCN), synthesized via an ultrasound-assisted physical mixing approach, for enhanced photocatalytic degradation of tetracycline antibiotic (TC). Comprehensive structural characterizations-including X-ray photoelectron spectroscopy (XPS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX), transmission emission spectroscopy (TEM) and X-ray diffraction (XRD)-demonstrated successful hybridization and interfacial integration, leading to favorable surface morphology and chemical environment. The formation of a well-aligned heterojunction facilitated efficient charge separation and broadened light absorption, as evidenced by photoluminescence and UV-vis diffuse reflectance spectroscopy analyses. The hybrid photocatalyst achieved a degradation efficiency of 87.5 %, with a rate constant of 0.0129 min-1, outperforming pristine BCN and Ce2(WO4)3 by factors of 1.2 and 1.6, respectively. Density functional theory (DFT) calculations revealed enhanced surface adsorption of TC on the hybrid interface, confirmed the thermodynamic stability of the BCN/Ce2(WO4)3 junction, and elucidated charge redistribution and chemisorption mechanisms involving boron, cerium, and tungsten active sites. This work presents the first comprehensive experimental-theoretical investigation of a BCN-Ce2(WO4)3 heterojunction, demonstrating a synergistic interface that improves light harvesting, charge separation, and pollutant adsorption compared to the individual components. These insights provide a fundamental basis for guiding the rational design of photo-catalysts for environmental remediation.