Topotactic Epitaxy of SrTiO₃ Mesocrystal Superstructures with Anisotropic Construction for Efficient Overall Water Splitting

Abstract

The higher-order structures of semiconductor-based photocatalysts play crucial roles in their physicochemical properties for efficient light-to-energy conversion. A novel perovskite SrTiO mesocrystal superstructure with well-defined orientation of assembled cubic nanocrystals was synthesized by topotactic epitaxy from TiO mesocrystals through a facile hydrothermal treatment. The SrTiO mesocrystal exhibits three times the efficiency for the hydrogen evolution of conventional disordered systems in alkaline aqueous solution. It also exhibits a high quantum yield of 6.7 % at 360 nm in overall water splitting and even good durability up to 1 day. Temporal and spatial spectroscopic observations revealed that the synergy of the efficient electron flow along the internal nanocube network and efficient collection at the larger external cubes produces remarkably long-lived charges for enhanced photocatalysis.

Recent Progress in Photocatalytic CO2 Reduction Over Perovskite Oxides

“…The topotactic epitaxial growth of nanostructured SrTiO 3 /TiO 2 creates abundant interfaces that promote charge separation and transfer. Recently, Majima et al used temporal and spatial spectroscopy to investigate the photo‐charge dynamics of an epitaxially grown SrTiO 3 nanocube mesocrystal superstructure (Figure ) . The nanocubes were in intimate contact within the mesocrystal superstructure, ensuring effective electron transfer channel between nanocubes.…”

From Solute, Fluidic and Particulate Precursors to Complex Organizations of Matter

“…(b) Mineral bridges and secondary nucleation: (i) continuity of crystal lattices of the adjacent tablets comprising a biogenic mineral and (ii) heterostructured microparticles comprising of vaterite cores and equatorial calcite ridges . (c) Topotactic phase transformation: topotactic epitaxy of SrTiO 3 mesocrystals originating from TiO 2 mesocrystals under hydrothermal conditions . (d) Alignment by particle surface stabilization: rationally designed polymer for directing the long‐range organization of laponite particles .…”

“…Here the temporal developments of distinct spatial patterns within the mineral particles reflect a potent spatiotemporal regulation of secondary nucleation achieved via the combined application of additives. Topochemical transformations also facilitate superstructured crystals, as evident by strontium titanate mesocrystals formed via single crystal anatase and SrTiO 3 mesocrystals grown from TiO 2 mesocrystals under hydrothermal conditions, (Figure c). Additives preferentially binding to crystal faces also govern particle co‐alignment and self‐association.…”

Highly Efficient Degradation of Tobacco Specific N‐Nitrosamines by TiO2 Mesocrystals with Robust and Tailored Microporous Structure

“…Furthermore, mesocrystals have remarkable versatility in chemical compositions compared with zeolites, and would hold a variety of promising properties. Mesocrystals also permit the advantages of single crystals as well as large surface area, making them more promising in the applications of catalysis, sensing and energy storage and conversion . In our and other group's previous work, TiO 2 mesocrystals with different phase and morphology were synthesized, which exhibited superior performance in energy storage and conversion, sensing and photocatalysis .…”