The development of highly efficient photocatalysts for
antibiotics
contamination in water remains a severe challenge. In this study,
In2O3 nanoparticle/Bi4O5Br2 nanosheet S-scheme heterojunction with interface oxygen
vacancies (OVs) was constructed by a hydrothermal-calcination approach
and a simple chemical precipitation process. Under simulated sunlight,
this composite showed enhanced degradation efficiency for tetracycline
hydrochloride (TCH) with 92.4%, which was much higher than those of
pure Bi4O5Br2 (50.2%) and In2O3 (28.6%). The excellent removal efficiency was
mainly attributed to the synergistic effect of S-scheme heterojunctions
and interface OVs accelerating the complexation of unwanted electrons
(e–) and holes (h+), thus retaining e– with the strong oxidizing ability and h+ with the strong reducing ability to participate in the reaction.
In addition, the abundant OVs in In2O3 nanoparticles/Bi4O5Br2 nanosheets could enhance the adsorption
of O2 and promote the generation of superoxide radicals
(·O2
–). The toxicity of the tetracycline degradation products and the
catalyst was evaluated by E. coli growth
inhibition experiments. Based on the TCH intermediates detected by
HPLC-MS, three possible TCH degradation pathways were proposed. This
study shows that the construction of S-scheme heterojunctions with
interfacial defects is an effective strategy for the preparation of
efficient photocatalysts.