Hierarchical flower-like NiAl-layered double hydroxide microspheres encapsulated with black Cu-doped TiO₂ nanoparticles: Highly efficient visible-light-driven composite photocatalysts for environmental remediation

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Herein, highly efficient composite photocatalysts comprising black Cu-doped TiO<SUB>2</SUB> nanoparticles (BCT) encapsulated within hierarchical flower-like NiAl-layered double hydroxide (LDH) microspheres were fabricated via a one-step hydrothermal route. Cu-doping and subsequent reduction treatment led to extended visible-light absorption of TiO<SUB>2</SUB> in the resulting composites, as confirmed by ultraviolet-visible diffuse reflectance spectral analysis. Moreover, thorough investigations confirmed the strong interactions between LDH and BCT in the resulting BCT/LDH composites. Notably, the BCT/LDH composites exhibited remarkable performance in the degradation of hazardous materials (methyl orange and isoniazid), superior to that of the individual components, reference P25, and P25/LDH under visible-light irradiation. Moreover, the BCT/LDH composite containing 30 wt% of BCT displayed the highest photocatalytic performance among the synthesized photocatalysts and also exhibited high stability during recycling tests with no obvious change in the activity. The superior photodegradation activity of the BCT/LDH composites was primarily attributed to efficient transfer and separation of the photoinduced charge carriers, resulting from the intimate contact interfaces between LDH and BCT. This approach represents a promising route for the rational design of highly efficient and visible-light-active LDH-based composite photocatalysts for application in energy harvesting and environmental protection.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel and highly efficient black Cu-doped TiO<SUB>2</SUB>/NiAl-LDH composites were fabricated. </LI> <LI> Both components in the composite system exhibited strong visible-light absorption. </LI> <LI> Composite system showed excellent performance for MO and isoniazid photodegradation. </LI> <LI> Rapid charge transfer at the interface contributed to remarkable photo-activity. </LI> <LI> The composite system exhibited high photostability during recycling experiments. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>