A multi-step ion-exchange methodology was developed for the fabrication of Cu(LaTa₂O₇)₂ lamellar architectures capable of wastewater depollution. The (001) diffraction line of RbLaTa₂O₇ depended on the guest species hosted by the starting material. SEM and TEM images confirmed the well-preserved lamellar structure for all intercalated layered perovskites. The UV–Vis, XPS, and photocurrent spectroscopies proved that Cu intercalation induces a red-shift band gap compared to the perovskite host. Moreover, the UV–Vis spectroscopy elucidated the copper ions environment in the Cu-modified layered perovskites. H₂-TPR results confirmed that Cu species located on the surface are reduced at a lower temperature while those from the interlayer occur at higher temperature ranges. The photocatalytic degradation of phenol under simulated solar irradiation was used as a model reaction to assess the performances of the studied catalysts. Increased photocatalytic activity was observed for Cu-modified layered perovskites compared to RbLaTa₂O₇ pristine. This behavior resulted from the efficient separation of photogenerated charge carriers and light absorption induced by copper spacer insertion.

Uniform ruthenium metal nanoparticles with an averagediameter of 5 nm have been prepared and supported on γ-Al₂O₃ up to 6.3 wt%. The Ru/Al₂O₃ catalyst prepared by this method had unusually high activity for ammonia synthesis. The rate of ammonia formation was at least 12 times higher than the rate of non-promoted Ru/Al₂O₃ catalysts prepared by conventional impregnation methods.

The adsorption sites of active carbon were found to promote efficiently the catalytic reduction of concentrated HNO₃ by HCOOH at low temperature.