Ingenious fabrication of Ni-doped Mg2Al-layered double hydroxide/g-C3N4 composite material for efficient photocatalytic degradation of tetracycline

Abstract

A 2D-2D Ni-doped Mg₂Al-layered double hydroxide/g-C₃N₄ (Ni-LDH/g-C₃N₄) composite material was ingeniously designed and prepared utilizing a green and facile strategy, which displayed an excellent photocatalytic performance for tetracycline degradation under visible light irradiation. The morphology of Ni-LDH material was the shape of nanosheets and its size was in the range of 200 to 400 nm, which was incorporated into g-C₃N₄ to construct 2D-2D composite structure. In the Ni-LDH/g-C₃N₄ composite materials, Ni-LDH materials played an important role in improving its separation and transfer efficiency of photo-generated charge carriers, as demonstrated by photoelectrochemical measurement. Thereinto, it can be obtained that the Ni-LDH/g-C₃N₄ materials possessed much higher photocatalytic performance than pristine g-C₃N₄ and Mg₂Al-layered double hydroxide/g-C₃N₄ materials, suggesting that it was much more beneficial to accelerate the photocatalytic reaction process. Additionally, the optimal Ni-LDH/g-C₃N₄ material, namely CNANi-10 sample, achieved a 73.3% degradation rate for tetracycline (10 ppm) within 90 min. Remarkably, the active species trapping experiments were implemented using the CNANi-10 sample, revealing that the superoxide radicals (·O₂⁻) and hole (h⁺) were the major active species to participate in the photocatalytic oxidation process. Prospectively, this work provides an efficient and low-cost strategy to construct efficient photocatalysts for water remediation.