High-efficiency treatment of antibiotic wastewater by a self-assembled coated double-heterojunction TiO2/g-C3N4/BN photocatalyst

Abstract

The treatment of antibiotic wastewater is one of the environmental problems that humans must solve. Low-cost and high-activity photocatalysts are the key to the treatment of antibiotic wastewater environments. In this work, a single-layer coated TiO₂/g-C₃N₄/BN (TCB) ternary composite heterojunction photocatalyst was successfully prepared. The appropriate amount of boron nitride (BN) was doped into the composite to form a I/II type double heterogeneous junction, which promoted the charge transfer and improved the separation efficiency of the photogenic carriers. Notably, a heterogeneous photocatalyst was constructed that could degrade tetracycline hydrochloride (TCH) in 30 min with a rapid degradation efficiency of 94.96%. When the light duration was increased to 60 min, the removal rate of TCH from aqueous solution could reach 99.16%. The reaction dynamics constant was 0.10128 s⁻¹, which was 5.73 and 3.27 times higher than that of TiO₂ and TiO₂/g-C₃N₄, respectively. This work reveals the potential application of ternary composites with double heterojunction for photocatalytic degradation as well as provides a reference value for titanium matrix composites for antibiotic wastewater treatment.