Ni–Al layered double hydroxide-coupled layered mesoporous titanium dioxide (Ni–Al LDH/LM-TiO2) composites with integrated adsorption-photocatalysis performance

Abstract

Nickel aluminum layered double hydroxides (Ni–Al LDHs) and layered mesoporous titanium dioxide (LM-TiO₂) were prepared via a simple precipitation process and novel precipitation–peptization method, respectively, and Ni–Al LDH-coupled LM-TiO₂ (Ni–Al LDH/LM-TiO₂) composites with dual adsorption and photodegradation properties were obtained via the hydrothermal approach. The adsorption and photocatalytic properties were investigated in detail with methyl orange as the target, and the coupling mechanism was systematically studied. The sample with the best performance was recovered after photocatalytic degradation, which was labeled as 11% Ni–Al LDH/LM TiO₂(ST), and characterization and stability studies were carried out. The results showed that Ni–Al LDHs showed good adsorption for pollutants. Ni–Al LDH coupling enhanced the absorption of UV and visible light, and the transmission and separation of photogenerated carriers were also significantly promoted, which was conducive to improving the photocatalytic activity. After treatment in the dark for 30 min, the adsorption of methyl orange by 11% Ni–Al LDHs/LM-TiO₂ reached 55.18%. Under illumination for 30 min, the decolorization rate of methyl orange solution reached 87.54%, and the composites also showed an excellent recycling performance and stability.