Spatial charge separation achieved on the anisotropic facets of high symmetry SrTiO ₃ nanocrystals for highly efficient photocatalytic overall water splitting.

The integrated architecture enables the Ta₃N₅photoanode to approach the theoretical photocurrent limit for solar water splitting.

Stable emission in glass: Lead halide perovskites can exhibit bright, narrow band photoluminescence but have stability issues related to formation of inactive phases and the loss of lead ions. Hou et al . show that the black, photoactive phase of cesium lead iodide can be stabilized by forming a composite with a glassy phase of a metal-organic framework through liquid-phase sintering. The photoluminescence is at least two orders of magnitude greater than that of the pure perovskite. The glass stabilizes the perovskite under high laser excitation, and about 80% of the photoluminescence was maintained after 10,000 hours of water immersion. —PDS

Providing sufficient driving force for charge separation and transfer (CST) is a critical issue in photoelectrochemical (PEC) energy conversion. Normally, the driving force is derived mainly from band bending at the photoelectrode/electrolyte interface but negligible in the bulk. To boost the bulky driving force, we report a rational strategy to create effective electric field via controllable lattice distortion in the bulk of a semiconductor film. This concept is verified by the lithiation of a classic TiO₂ (Li-TiO₂) photoelectrode, which leads to significant distortion of the TiO₆ unit cells in the bulk with well-aligned dipole moment. A remarkable internal built-in electric field of ~2.1 × 10² V m⁻¹ throughout the Li-TiO₂ film is created to provide strong driving force for bulky CST. The photoelectrode demonstrates an over 750% improvement of photocurrent density and 100 mV negative shift of onset potential upon the lithiation compared to that of pristine TiO₂ film.