Synthesis of high yield, crystalline and thermally stable rare earth (Sm, Eu, Gd) oxide square nanoplates for near-infrared light activatable photocatalysis

Abstract

Nanomaterial-mediated photocatalytic dye degradations are playing a key role in environmental remediation applications. However, most of the photocatalysts are typically activated by ultraviolet (UV) or visible light, whereas the utilization of near-infrared (NIR) light is seldom reported. To this end, here we present a cost-effective and straightforward method for preparing high-yield, active surface, thermally stable rare earth oxide (REO) square nanoplates (SNPs) for NIR light photocatalytic dye degradation applications. Herein, we present a process involving hydrothermolysis followed by a thermal calcination strategy for the preparation of REO photocatalysts, which offers crystalline and thermally stable REO SNPs with greater yields. Furthermore, the NIR photocatalytic dye degradation ability on the calcinated REO SNPs with an active surface is better than that on non-calcinated REO SNPs. Specifically, a 7-fold higher degradation efficiency was achieved on the calcinated REO SNPs within 240 minutes. The enhanced photocatalytic degradation on the REO SNPs is mainly attributed to the dominant generation of reactive oxygen species (such as ˙OH and ¹O₂) under NIR light excitation. Overall, we strongly believe that the present simple fabrication strategy of high purity REO-based nanocrystals will open a new path to develop highly active nanomaterials for future photocatalytic applications.