Nitrogen and sulfur co-doped titanium oxide (N─S co-doped TiO2) nanoparticles (NPs) are synthesized using Dactylorhiza hatagirea root extract. After characterization, nanoparticles are used as photocatalysts for the degradation of methyl orange (MO) dye under visible light irradiation.

Abstract

Environmental pollution significantly threatens ecosystems and human health, necessitating effective solutions for pollutants. Photocatalytic degradation has been a promising, effective, and sustainable approach for addressing this challenge due to its efficiency and sustainability. This work describes the green synthesis of nitrogen and sulfur co-doped titanium oxide nanoparticles (N,S co-doped TiO₂NPs) using Dactylorhiza hatagirea root extract and investigated their photocatalytic degradation performance for methyl orange (MO) under visible light irradiation. The synthesized nanoparticles exhibited a uniform spherical morphology with an average size of 155 nm. The successful doping and structural properties of TiO₂ were studied using SEM, XRD, FTIR, DLS, and UV–visible (UV–vis) spectroscopy. Photocatalytic tests demonstrated a remarkable degradation efficiency of 99.5% for MO within 45 min under optimal conditions (pH 12, 30 mg photocatalyst, 10 ppm MO concentration). LC–MS analysis revealed the degradation pathway, identifying various intermediate products. This study underscores the potential of green-synthesized N,S co-doped TiO₂ NPs for efficient photocatalytic applications and developing sustainable environmental remediation technologies with advantages of ecological preservation and public health.