Hydrogen production from photoelectrochemical (PEC) water splitting using semiconductor photocatalysts has attracted great attention to realize clean and renewable energy from solar energy. The visible light response of WO₃ with a long hole diffusion length (∼150 nm) and good electron mobility (∼12 cm² V⁻¹ s⁻¹) makes it suitable as the photoanode. However, WO₃ suffers from issues including rapid recombination of photoexcited electron–hole pairs, photo-corrosion during the photocatalytic process due to the formation of peroxo-species, sluggish kinetics of photogenerated holes, and slow charge transfer at the semiconductor/electrolyte interface. This work highlights the approaches to overcome these drawbacks of WO₃ photoanodes, including: (i) the manipulation of nanostructured WO₃ photoanodes to decrease the nanoparticle size to promote hole migration to the WO₃/electrolyte interface which benefits the charge separation; (ii) doping or introducing oxygen vacancies to improve electrical conductivity; exposing high energy crystal surfaces to promote the consumption of photogenerated holes on the high-active crystal face, thereby suppressing the recombination of photogenerated electrons and holes; (iii) decorating with co-catalysts to reduce the overpotential which inhibits the formation of peroxo-species; (iv) other methods such as coupling with narrow band semiconductors to accelerate the charge separation and controlling the crystal phase via annealing to reduce defects. These approaches are reviewed with detailed examples.

The inherent brittleness of ceramics, primarily due to restricted atomic motions from rigid ionic or covalent bonded structures, is a persistent challenge. This characteristic hinders dislocation nucleation in ceramics, thereby impeding the enhancement of plasticity through a dislocation-engineering strategy commonly used in metals. Finding a strategy that continuously generates dislocations within ceramics may enhance plasticity. Here, we propose a “borrowing-dislocations” strategy that uses a tailored interfacial structure with well-ordered bonds. Such an approach enables ceramics to have greatly improved tensile ductility by mobilizing a considerable number of dislocations in ceramic borrowed from metal through the interface, thereby overcoming the challenge associated with direct dislocation nucleation within ceramics. This strategy provides a way to enhance tensile ductility in ceramics.

Here we report a facile hydrothermal route for the preparation of BiOBr–Bi₂WO₆ mesoporous nanosheet composites (MNCs) in the presence of titanium isopropoxide, Ti(OⁱPr)₄. High resolution transmission electron microscopy, X-ray diffraction, nitrogen adsorption/desorption analysis and X-ray photoelectron spectroscopy were employed for structural and composition analyses of the MNCs. The photogenerated charge transfer and photocatalytic activity of BiOBr–Bi₂WO₆ MNCs were investigated by Kelvin probe force microscopy and UV-vis spectroscopy. We propose mechanisms to illustrate how titanium alkoxide induces the formation of mesoporous nanosheet heterostructures and the enhanced photodecomposition efficiency of the dye under low light intensity illumination. Overall, our results suggest that titanium alkoxide is not only strongly involved in the growth of BiOBr (001) facets, but also plays a critical role in the pore evolution of the product. Kelvin probe force microscopy analysis allows us to conclude that the resulting nanocomposites demonstrate high photogenerated charge mobility and a long lifetime. Dye molecules can be rapidly and thoroughly decomposed with the photocatalyst under very low light intensity illumination. The enhanced photocatalytic activity is attributed to well matched band edge positions of BiOBr and Bi₂WO₆ and the large specific surface area of the MNCs in view of the incorporation of mesopores and the highly exposed BiOBr (001) facet due to the use of Ti(OⁱPr)₄ during the synthesis. The results presented here are expected to make a contribution toward the development of delicate nanocomposites for photocatalytic water purification and solar energy utilization.