Formation of monolithic SrTiO3-TiO2 ceramic heterostructures by reactive hydrothermal sintering

In a one-pot approach, monolithic SrTiO3-TiO2 ceramic heterostructures were obtained using the reactive hydrothermal liquid phase densification (rHLPD). Structural, morphological, and photocatalytic properties of the obtained ceramics were analyzed. The relative density of the formed components reached about 80% with reaction time, temperature, and NaOH concentration variation. It was observed via Rietveld refinement that there was no XRD detectable phase other than TiO2 and SrTiO3 in the final structure. The monolithic SrTiO3-TiO2 ceramics obtained by hydrothermal reaction at 120 degrees C for 24 h in 1 M NaOH concentration showed a dielectric constant being around 500, and the dielectric loss was below 0.25 at frequencies higher than 10 kHz. The SrTiO3-TiO2 heterostructured monoliths having only 20 vol% total porosity and low specific surface area, demonstrated similar to 60% efficiency (in 5 h) in degrading Methylene Blue photo-catalytically.

Automated summary

Monolithic SrTiO3-TiO2 ceramic heterostructures were successfully prepared using the reactive hydrothermal liquid phase densification method. The obtained ceramics were analyzed for structural, morphological, and photocatalytic properties. It was found that the final structure consisted of TiO2 and SrTiO3 phases, and the ceramics showed high dielectric constant and low dielectric loss. The SrTiO3-TiO2 heterostructured monoliths exhibited efficient photocatalytic degradation of Methylene Blue.