Band-Gap Engineering of Layered Perovskites by Cu Spacer Insertion as Photocatalysts for Depollution Reaction

Abstract

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.

Effect of the Modification of Catalysts on the Catalytic Performance

“…Raciulete et al [5] developed a multi-step ion-exchange methodology for the fabrication of Cu(LaTa 2 O 7 ) 2 lamellar architectures by exchanging Rb + with a much smaller Cu 2+ spacer in the RbLaTa 2 O 7 host to achieve photocatalysts capable of wastewater depollution. Cu-modified layered perovskites exhibited enhanced photocatalytic activity compared to the RbLaTa 2 O 7 host.…”

The steric effect of exfoliation agent for fabrication of layer niobium oxide nanosheet

“…Nowadays, Two‐dimensional materials (e.g., Graphene, MoS 2 , etc. ) 1–5 and layered perovskite oxides have attracted worldwide attention because their properties can be applied in several applications such as photocatalyst, 6–8 semiconductor, 9 and energy storage 10–12 . The conventional structure of layer perovskite can be categorized into three phases (i.e.…”