Boosted Photo-Fenton Degradation over a Composite Catalyst Based on FeOOH Nanoparticles Anchored on a Flower-like BaTiO₃ Microsphere

The conventional heterogeneous photo-Fenton systems suffer from limited surface active sites, sluggish Fe 3+ /Fe 2+ cycle, and low activation efficiency of hydrogen peroxide, thus limiting their applications. Herein a 0D/3D FeOOH/BaTiO 3 composite photo-Fenton catalyst system was proposed. The typical microstructure in which FeOOH nanoparticles uniformly anchored on the flower-like BaTiO 3 microsphere endows the composite catalysts with abundant active sites and intimate heterojunctions, which are conducive to charge carrier separation and transportation, as confirmed by the electrochemical and XPS characterization results. Benefiting from these advantages, the degradation rate of RhB with 1:4 FeOOH/BaTiO 3 was significantly increased to 0.23 min –1, which was 40.5 and 7.9 times higher than that of BaTiO 3 and FeOOH when a trace amount of H 2 O 2 (6 mM) was present. In addition, the catalysts also showed superior degradation efficiency in decomposing the antibiotic TC and possessed high recycle stability. The triggered Fenton reactions give rise to abundant • OH, which was confirmed to be the dominated active species. According to the band structure analysis and control experiment results, it was believed the smooth photoelectron transfer from BaTiO 3 to FeOOH accelerated the Fe 3+ /Fe 2+ cycle, facilitated activation of H 2 O 2, and boosted photo-Fenton reactions. This work provides a perspective on the design of high-performance photo-Fenton catalysts to tackle wastewater treatment.