Carbon, nitrogen co-doped TiO2 nanoparticles via sol-gel route: An approach for chlorpyrifos degradation
Nur Adilah Adanan, Nurul Hidayah Mohamad Idris, Hooi Ling Lee
Abstract
The photocatalytic degradation of wastewater is the most promising environmental remediation. This study focused on chlorpyrifos as a model pollutant due to its widespread use as an organophosphate insecticide. Carbon and nitrogen co-doped titanium dioxide nanoparticles (C, N-TiO 2 NPs) were synthesized using a sol-gel method, employing titanium isopropoxide, urea, and carboxymethylcellulose as titanium, nitrogen, and carbon precursors, respectively. The C, N-TiO 2 NPs were characterized using X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, UV-visible diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy (HRTEM) for the optical, chemical and physical characteristics. Analytical results from XRD and HRTEM revealed anatase-phase structures with a reduced bandgap energy of 2.95 eV. Compared to pure anatase TiO 2 , the synthesized C, N-TiO 2 NPs exhibited slower electron-hole pair recombination, according to PL analysis. Under solar light irradiation, an optimal catalyst dosage of 0.12 g achieved 90% chlorpyrifos breakdown at 8 ppm concentration and 62.1% mineralization degree, with superoxide radicals (•O 2 - ) as the dominant ROS. The photocatalyst exhibited remarkable reusability, achieving 79.5% removal of chlorpyrifos over five cycles during photodegradation processes. Thus, this study creates TiO 2 NPs doped with carbon and nitrogen as an effective photocatalyst for wastewater treatment. • The creation of visible light-activated C, N-TiO 2 photocatalyst by sol-gel method • The synergistic effect of C and N doping improves its photocatalytic performance • Enhanced optical and photocatalytic photocatalyst boost chlorpyrifos degradation • •O 2 - plays a key role in the degradation mechanism of chlorpyrifos • Great reusable C, N-TiO 2 photocatalyst for wastewater treatment applications