Unveiling the photocatalytic application of niobia based n-n heterojunction for degradation of tetracycline: A sustainable approach for water treatment

Abstract

This study investigates the efficacy of a novel Nb2O5–MoO3 n-n heterojunction as a photocatalyst for the degradation of tetracycline in aqueous solution. The synthesized heterojunction shows remarkable photocatalytic activity attributed to the synergistic effect of niobium pentoxide (Nb2O5) and molybdenum trioxide (MoO3). Various characterization techniques, including X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy etc., were employed to elucidate the structural and morphological features of the heterojunction. The band gap energy and surface area were observed to be 2.55 eV and 32.897 m2/g respectively. The photocatalytic degradation of tetracycline was systematically studied under various experimental conditions, including catalytic dosage, initial tetracycline concentration and wavelength of irradiation light. These results reveal the greater efficiency of Nb2O5–MoO3 heterojunction compared to that of pristine Nb2O5 with a complete degradation achieved in 60 min under visible region with a degradation rate of 4.9 × 102 min−1. Furthermore, the catalyst demonstrates excellent stability over multiple cycles of use.