Amorphous FeOOH shell decorated Bi2O4 for the boosted photocatalytic degradation of tetracycline under visible irradiation

At present, the regulation of photocatalyst properties and highly efficient degradation of emerging contaminants are still challenging tasks. Herein, a novel core-shell composite catalyst Bi2O4 @FeOOH was fabricated by in situ depositing amorphous FeOOH nanoparticles on the outside surface of Bi2O4. A series of characterizations were conducted for the fabricated Bi2O4 @FeOOH. The photocatalytic activity of Bi2O4 @FeOOH was assessed via the degradation of tetracycline (TC) under visible irradiation. The formation of the amorphous FeOOH shell improves the visible-light harvesting capability, enlarges the specific surface area, and accelerates the transfer of the photo-induced electron. The synergistic effect of these positive factors enables the prepared Bi2O4 @FeOOH to exhibit a considerably reinforced activity and excellent stability for TC degradation. The degradation efficiency of TC on Bi2O4 @FeOOH is up to 84.2%, which is markedly higher than that over FeOOH (20.4%) and Bi2O4 (43.5%). After five reuses, the activity of Bi2O4 @FeOOH shows no obvious decrease. The degradation rate constant of TC by Bi2O4 @FeOOH is 0.01434 min−1, which is approximately 2.4 and 5.8 times those by Bi2O4 and FeOOH. This work affords a new strategy for the design of highly efficient photocatalysts that can be applied in the photocatalytic decomposition of emerging contaminants.