Synthesis of magnesium doped bismuth oxide for the photocatalytic degradation of methyl orange and tetracycline

This study focuses on the synthesis of Mg-doped bismuth oxide via precipitation method for the photocatalytic degradation of methyl orange (MO) and tetracycline (TC). The synthesized materials were characterized using XRD, FT-IR, UV-DRS, PL, FE-SEM and EDAX. These analyses confirmed the successful formation of Mg-doped Bi 2 O 3 with agglomerated morphologies and enhanced optical properties. XRD patterns revealed the formation of monoclinic Bi 2 O 3 , and doping-induced alterations in diffraction peak intensities and average crystallite size. Doping Bi 2 O 3 with Mg significantly reduced photoluminescence (PL) emission intensity, indicating suppressed radiative recombination and enhanced charge carrier separation. Mechanistic analysis identified superoxide radicals ( • O 2 − ) and holes (h + ) as the primary active species in pollutant degradation. This investigation underscores the potential of Mg-doped Bi 2 O 3 as efficient photocatalysts for mitigating water pollution caused by persistent organic contaminants like methyl orange and tetracycline. The results contribute valuable insights into the development of advanced materials for environmental remediation and sustainable water treatment technologies. • Mg-doped Bi 2 O 3 was synthesized via a simple precipitation method, showing good structural stability for photocatalytic use. • The catalyst efficiently degraded methyl orange and tetracycline under light, demonstrating strong photocatalytic activity. • Improved performance was linked to enhanced charge separation, s PL quenching, increased photocurrent, and lower EIS resistance. • Scavenger tests confirmed superoxide radicals and holes as the key species driving the pollutant degradation.