A hierarchical 3D hybrid CoAl-layered double hydroxide/TiO2/Ti3C2 MXene S-scheme photocatalyst with 2D/0D/2D contact interfaces for sustainable pollutant degradation

초록

Environmental pollution, particularly that derived from waterborne antibiotics, is a rising concern because of its detrimental effects on aquatic ecosystems and human health. Hence, in this study, we present a hierarchical 3D-structured hybrid photocatalyst comprising a CoAl-layered double hydroxide (LDH), TiO2, and Ti3C2 MXene synthesized using an in situ hydrothermal method. Various characterization techniques revealed that the hybrid CoAl-LDH/TiO2/Ti3C2 photocatalyst exhibited improved optical absorption, and the tailored 2D/0D/2D contact interfaces among the constituents enhanced charge migration and minimized electron-hole recombination. The results of electron paramagnetic resonance and in situ-irradiated X-ray photoelectron spectroscopy analyses confirmed that the hybrid photocatalyst follows an S-scheme mechanism that not only promotes the separation of photoinduced electron-hole pairs but also preserves their robust redox capability. The amalgamation of the three components resulted in synergistic advantages. Consequently, the optimized CoAl-LDH/TiO2/Ti3C2 photo-catalyst exhibited remarkable performance in degrading and mineralizing the antibiotic diclofenac sodium (DFS) and the dyes rhodamine B and indigo carmine, surpassing its constituents and previously reported photo-catalysts. Furthermore, the hybrid retained high efficiency across multiple cycles, underscoring its potential reusability. Therefore, this study demonstrates the potential of the developed hybrid photocatalyst for sustain-able water treatment, thereby fostering cleaner aqueous environments.

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