Charge carrier recombination processes, intragap defect states, and photoluminescence mechanisms in stoichiometric and reduced TiO brookite nanorods: an interpretation scheme through photoluminescence excitation spectroscopy in controlled environment.

The study of titanium dioxide (TiO) in the brookite phase is gaining popularity as evidence has shown the efficient photocatalytic performance of this less investigated polymorph. It has been recently reported that defective anisotropic brookite TiO nanorods display remarkable substrate-specific reactivity towards alcohol photoreforming, with rates of hydrogen production significantly (18-fold) higher than those exhibited by anatase TiO nanoparticles. To elucidate the basic photo-physical mechanisms and peculiarities leading to such an improvement in the photoactive efficiency, we investigated the recombination processes of photoexcited charge carriers in both stoichiometric and reduced brookite nanorods photoluminescence excitation spectroscopy in controlled environment.

Nanoporous Titanium Oxynitride Nanotube Metamaterials with Deep Subwavelength Heat Dissipation for Perfect Solar Absorption.

We report a quasi-unitary broadband absorption over the ultraviolet-visible-near-infrared range in spaced high aspect ratio, nanoporous titanium oxynitride nanotubes, an ideal platform for several photothermal applications. We explain such an efficient light-heat conversion in terms of localized field distribution and heat dissipation within the nanopores, whose sparsity can be controlled during fabrication. The extremely large heat dissipation could not be explained in terms of effective medium theories, which are typically used to describe small geometrical features associated with relatively large optical structures.

Ultrasound-Driven Defect Engineering in TiO Nanotubes─Toward Highly Efficient Platinum Single Atom-Enhanced Photocatalytic Water Splitting.

Single-atom catalysts (SACs) have demonstrated superior catalytic activity and selectivity compared to nanoparticle catalysts due to their high reactivity and atom efficiency. However, stabilizing SACs within hosting substrates and their controllable loading preventing single atom clustering remain the key challenges in this field. Moreover, the direct comparison of (co-) catalytic effect of single atoms vs nanoparticles is still highly challenging.