Nickel aluminum layered double hydroxide nanosheets grown on oxygen vacancy-rich TiO2 nanobelts for enhanced photodegradation of an antibiotic

Nickel aluminum layered double hydroxide nanosheets were grown on oxygen vacancy-rich TiO2 nanobelts to form heterostructured TiO2/NiALLDH photocatalysts. The as-prepared samples were characterized systematically by various techniques. The visible-light response of NiAl-LDH and oxygen-vacancy rich TiO2 created a direct Z-scheme heterojunction, thus contributing to the excellent photoactivity of the composite photocatalysts. Specifically, the close contact between NiAl-LDH and TiO2 at the interface promoted the directional transport of charge carriers. Tetracycline hydrochloride was selected as the target pollutant to examine the catalytic activity of samples under visible light irradiation. The results indicated that the optimal sample 2TiO(2)-4/NiALLDH exhibited excellent activity in the degradation of tetracycline hydrochloride (TC-H), and it's degradation rate was 5 and 2.5 times than that of NiAl-LDH and TiO2-4, respectively. Moreover, the active species h(+), O-center dot(2)-, and (OH)-O-center dot played significant roles in the process. According to the experimental results, the visible-light driven degradation mechanism of TC-H over 2TiO(2)-4/NiALLDH was elucidated.

Automated summary

The growth of nickel aluminum layered double hydroxide nanosheets on oxygen vacancy-rich TiO2 nanobelts resulted in the formation of heterostructured TiO2/NiAL-LDH photocatalysts, contributing to excellent photoactivity. The direct Z-scheme heterojunction between NiAl-LDH and oxygen-vacancy rich TiO2, along with the role of active species, significantly influenced the degradation mechanism of tetracycline hydrochloride under visible light irradiation. The directional transport of charge carriers between NiAl-LDH and TiO2 at the interface played a crucial role in enhancing the catalytic activity of the composite photocatalysts.