Photoelectrochemical performance of facet-controlled TiO2 nanosheets grown hydrothermally on FTO

Spontaneous Dewetting of Au-Thin Layers on Oxide- and Fluorine-Terminated Single Crystalline Anatase and Efficient Use in Photocatalytic H2 Production

In the present work, the spontaneous dewetting of thin Au layers on single crystalline anatase nanosheets into narrow-disperse Au nanoparticles is investigated. Patterns of the Au particles can be formed on the main facets of anatase that provide a high co-catalytic activity for photocatalytic generation of H2 . Dewetting is distinctly influenced by the respective facets (001) and (101), the deposit thickness, and secondary thermal dewetting, but most strongly by the surface termination of the nanosheets. Fluoride termination not only leads to an enhanced Au-phobic behavior but strongly affects the co-catalytic activity for photocatalytic generation of H2 . While fluoride termination with or without Au decoration is detrimental for hole transfer, the interplay of the Au co-catalyst and surface fluoride yields highly beneficial effect for electron transfer. This results in a three-times higher photocatalytic H2 production for the F-terminated surface. The findings suggest that dewetting of Au on surface fluorinated TiO2 is an effective way to modulate surface dewetting and achieve a strongly enhanced photocatalytic activity.

Crystal facet and phase engineering for advanced water splitting

This review covers the principles and recent advances in facet and phase engineering of catalysts for photocatalytic, photoelectrochemical, and electrochemical water splitting. It suggests the basis of catalyst design for advanced water splitting.

A drastic improvement in photocatalytic H2 production by TiO2 nanosheets grown directly on Ta2O5 substrates

Titanium dioxide (TiO₂) is the most frequently studied semiconducting material for photocatalytic water splitting. One of the favored forms of TiO₂ for photocatalytic applications is layers of erected single-crystalline anatase nanosheets (NSs), while the most frequently reported substrate used for its synthesis is a fluorine-doped tin oxide (FTO). Herein we demonstrate that anatase TiO₂ NS layers can be similarly grown on a Ta₂O₅ substrate. We found that a Ta₂O₅ back contact provides a remarkable improvement of the photocatalytic activity of the TiO₂ NSs in comparison to a FTO back contact. The TiO₂ NSs on Ta₂O₅ exhibit a 170-fold increase in photocatalytic H₂ production rate than that obtained by TiO₂ NSs on FTO substrate. The proposed mechanism reveals that such a drastic enhancement of optimized TiO₂ NS arrays on the Ta₂O₅ substrate is attributed to the blocking nature of Ta₂O₅ for photo-generated electrons in the TiO₂ NSs.