Comment on “Ferroelectric composite-based piezoelectric energy harvester for self-powered detection of obstructive sleep”

SrTi2O5 particles were claimed by Panda et al. in J. Materiomics 2023;9:609 as a new lead-free ferroelectric material with orthorhombic symmetry and space group of Cmm2, being, therefore, employed as a base of piezoelectric energy harvesters. However, in this comment we express concerns regarding the presence of the piezoelectricity in the studied material and the interpretation of the structural, microstructural, and ferroelectric results in that publication as those associated with SrTi2O5. We also note that the presented dielectric results are contradictory and that many important details are missing.