Enhanced visible-light-driven photocatalytic degradation of tetracycline by 16% Er3+-Bi2WO6 photocatalyst

The widespread use of antibiotics in drug therapy and agriculture has seriously polluted the aquatic environ -ment. Bismuth tungstate (Bi2WO6) is a new and efficient visible-light catalyst that is simple to prepare, non-toxic, stable, and corrosion resistant. Nonetheless, its efficiency has remained limited, and erbium (Er) mixing has been tested to address this. Here, a new Er3+-mixed Bi2WO6 photocatalyst was successfully prepared through the one-step hydrothermal method; pigments were characterized via XRD, SEM, BET, XPS, Uv-vis, PL and EIS. The results showed that the 16% Er3+-Bi2WO6 photocatalyst is a 250 nm flower-like nanosheet with a specific surface area of 67.1 m(2)/g and bandgap (Eg) of 2.35 eV, which provides the basis for superior performance. When the con-centration of the catalyst was 0.4 g/L, 94.58% of the tetracycline (TC) solution (initial concentration of 10 mg/L) degraded within 60 min under visible light irradiation (lambda >= 420 nm). ESR and LC-MS were used to identify the free radicals and intermediates for the degradation of TC pollutants; a photocatalytic degradation system and pathway were proposed. This solar-driven system will ultimately reduce resource consumption, providing a sustainable and energy-saving environmental decontamination strategy.

Automated summary

A new Er3+-mixed Bi2WO6 photocatalyst was successfully prepared and demonstrated to efficiently degrade tetracycline pollutants under visible light irradiation. The catalyst showed promising characteristics for environmental purification applications and proposed a photocatalytic degradation system and pathway for tetracycline pollutants.