Anisotropy of Single-Crystal Semiconductors in Photo(electro)Catalysis.

Anisotropy in single-crystal semiconductors has emerged as a key design principle for understanding and advancing photo(electro)catalytic systems. The exposure of well-defined facets in single-crystal semiconductors introduces anisotropic variations in atomic coordination, electronic structure, and surface energetics, giving rise to directional charge transport and facet-specific reactivity. Such intrinsic differences coordinate the entire photocatalytic process, from charge excitation and separation to interfacial reaction kinetics.

Al-Dependent Anisotropic Facet Tailoring on SrTiO Single Crystal for Photocatalytic Overall Water Splitting.

Controllable fabrication of single-crystal metal oxide is of paramount importance for advanced photo(electro)catalytic applications, but achieving nonequilibrium crystal shapes with tailored facets through molten salt synthesis still remains a challenge. Herein, we systematically explored the effect of Al concentration in tailoring crystal facets of SrTiO single crystals and developed a one-step molten salt strategy for engineering anisotropic structures by using miscible AlCl as Al additive. By progressively increasing Al concentration, a series of high-quality SrTiO single crystals exposing {100}, {111}, and {110} facets were sequentially synthesized.

Palladium Hydride Anchored on SrTiO with Efficient Charge Separation and Surface Reaction Kinetics for Enhanced Photocatalytic Overall Water Splitting.

Cocatalyst engineering is critical for advancing photocatalysis, as it suppresses charge carrier recombination, promotes interfacial electron/hole extraction, and serves as active sites for redox reactions. However, the incompatibility existing between the cocatalyst and host photocatalyst, along with its intrinsic properties of active sites, limits further improvements in the charge separation, surface reaction kinetics, and overall performance. Herein, we introduce palladium hydrides (PdH) as an efficient cocatalyst on SrTiO (STO) for photocatalytic overall water splitting, owing to their similar lattice parameters.

Template-free synthesis of single-crystal SrTiO nanocages for photocatalytic overall water splitting.

In this study, we present a novel approach to achieve the template-free fabrication of nanocage-shaped SrTiO (N-STO) single crystals molten salt flux treatment. Systematic characterizations demonstrate the high crystallinity and low defect density of N-STO. The N-STO single crystals enable overall water splitting (OWS) with hydrogen and oxygen evolution rates of 100.