Perovskite Micro-Nano Cage SrTiO₃: Formation Mechanism, Vacancy Analysis, and Exciton Dynamics

Abstract

In the former research, we produced the regular polyhedron single-crystalline SrTiO3 particles with multiple crystal facets exposed by a one-step hydrothermal method. In this work, the dissolution process mechanism of SrTiO3 has been analyzed based on the evidence of the crystal structure and particle morphology with a completely new point of view. The anisotropic formation process of perovskite micro-nano cage SrTiO3 was primarily summarized, and the defective vacancy composition was analyzed. Simultaneously, based on femtosecond transient absorption spectroscopy, the exciton dynamic of SrTiO3 was deduced, and it will play a key role in improving the photoelectric properties of SrTiO3. Furthermore, the abundant defective vacancies promote the ability of SrTiO3 to oxidize Co species, which has a great advantage in the wastewater treatment processes.

A unique octadecahedron SrTiO3 perovskite oxide with a nano step-shaped facet structure for enhanced photoredox and hydrogen evolution performance

“…Meanwhile, TEM mapping (Fig. 1f) shows that the distribution of Sr, Ti, and O for Step-STO-SSR was roughly consistent with that of the octadecahedron STO in the previous work, 12 although the distribution of O was uneven, which is the signal deviation caused by the uneven interface due to the existence of step-shaped facets on the surface of STO. In addition, the impurity attached to STO belonged to the Ti-O compounds, which should be caused by incomplete dispersion.…”

“…Subsequently, we synthesized micro-nano cage SrTiO 3 with (110) crystal facets as a frame and hollowed out (100) crystal facets by a one-step hydrothermal method for the rst time. 11,12 The multi-defect vacancies of hollow micro-nano cage SrTiO 3 possessed a selftrapping exciton feature and, consequently, higher efficiency for separation and longer carrier lifetime were achieved.…”

CO2 Pressure‐Induced Self‐Trapped Excitons in SrTiO3

“…The TA data of SrTiO 3 under SC CO 2 treatment display that excited‐state absorption occurs at ≈300 fs followed by immediate excited radiation, which is the process from carrier generation to recombination, and finally STEs were produced. [ 28 ] With the increase of delay time, the STE–PIA signal of SrTiO 3 under SC CO 2 treatment becomes stronger and finally maintains a positive absorption signal quickly, while the positive signal appears after a negative oscillation of the ultrasonic sample, whose signal strength is lower than SC‐CO 2 ‐treated SrTiO 3 .…”

Pressure Coupled Lanthanide Ion Doping to Enhance Optical Properties in BaTiO3

“…Moreover, the formation process of STEs is shown in Figure 3e. The TA data display that excited state absorption occurs at ≈220 fs followed by immediate excited radiation, which is the process from carrier generation to recombination, and finally STEs were produced [ 27 ] . With the increase in delay time, the STE–PIA signal becomes stronger and finally maintains a positive absorption signal quickly.…”