Temperature-induced lattice distortion in CuGeO3 nanocrystals

Lattice distortion represents the fundamental factor of crystalline materials and contributes significantly to structural-related properties. Herein, we discover an unexpected temperature-induced lattice distortion in CuGeO3 nanocrystals, resulting in color changes of CuGeO3. The structural distortions in CuGeO3 nanocrystals are characterized by Rietveld analysis in detail, where its cell parameter b and cell volume reveal first decrease and then increase characteristics and correspond well with the XRD patterns and Raman spectra. Besides, both the experimental characterizations and theoretical calculations confirm that the optical and band structural changes mainly arise from the twisted octahedral field of [CuO6], where the lattice distortions regulate the crystal field splitting energy of [CuO6] and account for its changed d-d transition. Furthermore, tetracycline photodegradation is employed as an example to evaluate the effect of lattice distortion on photocatalytic performance, which also highlights the importance of modulating lattice distortion in photocatalysis. This work provides an approach to simply regulate the lattice distortion for nanorods by manipulating calcination temperatures.