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Photoelectrochemical (PEC) nanomaterials are critical to producing clean oxygenation or value-added chemical production by utilizing sustainable solar energy, but are always limited by simultaneous integration of architectural engineering and electronic regulation in one structure. Directed by density functional theory (DFT) calculations and finite element analysis (FEA), the bio-inspired ivy-like Fe2O3 heterostructures with enriched oxygen defects on TiO2 nanofibers are designed for boosting PEC performances. Ivy-like Fe2O3 photo-sheets remarkably enhanced the light harvesting by multiple light-mater interactions. The oxygen vacancies on Fe2O3 photo-sheets could aid the photons catching and promote the reactivity at active sites. More importantly, demonstrated by a well-designed dynamic observation, the abundant tip-edges within ivy-like Fe2O3 photo-sheets enabled the surface of heterostructure with hydrophilic and aerophobic properties. The functionalized surface allowed the rapid desorption of produced bubbles and thus ensured a high density of unoccupied active sites for electrolyte accessing. Featured by these attributes, the Fe2O3@TiO2 nanofibers delivered an excellent photocurrent of 40.8 mA/mg, high donor density (1.2 × 1018 cm−3), and rapid oxygen production rate (1 mmol/(L·h)). This work demonstrates a new strategy on nano-structural design for enhancing light-harvesting and making a hydrophilic/aerophobic surface on low-dimensional oxide nanomaterial, holding great potential on designing high-performance PEC devices for producing survival source gas, carbon-neutral fuel, and valued-chemicals. [ABSTRACT FROM AUTHOR]

Pt/TiO 2 nanofibers (Pt/T-NFs) composite catalysts are prepared through the combination of an electrospinning technique with a reductive impregnation method. Obtained samples are analyzed by various techniques, such as transmission electron microscopy and X-ray diffraction, which reveal that 21 wt.% Pt/T-NFs sample has a homogeneous distribution of smaller Pt nanoparticles of about 4.5 nm in size on the TiO 2 nanofibers surface without large aggregations. Electrochemical studies are carried out using cyclic voltammetry, chronoamperometry and CO stripping voltammetry, which indicate that 21 wt.% Pt/T-NFs catalyst has higher electrochemical surface area and much better activity for methanol electro-oxidation. All Pt/T-NFs catalysts have enhanced stability and CO tolerance for methanol electro-oxidation than commercial Pt/C. The results suggest that Pt/TiO 2 nanofibers catalysts exhibit the better activity for methanol oxidation and are favorable for improving the tolerance to poisoning species. [ABSTRACT FROM AUTHOR]

• The surface uniformity of substrate was optimized toward sinter-resistant catalyst. • TiO 2 nanofibers were decorated with well-defined rutile nanorods as substrate. • 3 nm-Pt NPs were stabilized under sinter-promoting situations over 600 °C. • Pt NPs on the nanorods-decorated-TiO 2 nanofibers were active for soot oxidation. One of the most urgent concerns for supported catalysts is to enhance their thermal stability against sintering upon high temperatures (above 300 °C). In this work, we decorated the rough surface of TiO 2 nanofibers with a sheath of rutile nanorods to improve their surface uniformity and explored them as new reliable substrates to stabilize Pt nanoparticles without capping shell. During preparation, the surface-initiated grain growth facilitates the decorated TiO 2 crystals to transform into rutile nanorods, exposing rutile {1 1 1} and {1 1 0} facets. With the presence of TiO 2 nanofibers, these rutile nanorods were finely confined against coalescence and reconstruction upon 700 °C, offering reliable supports for stabilizing metal nanoparticles. Therefore, the diminished driving force for sintering enables the whole catalyst system to withstand temperatures up to 500 °C at an oxidative atmosphere. After calcination at 500 °C, the Pt on rutile nanorods-decorated-TiO 2 nanofibers exhibited nearly 3-times higher reaction rate constant (27.8 s−1·g−1·L−1) toward hydrogenation of 4-nitrophenol over those on unmodified TiO 2. Moreover, such a thermally stable catalyst was active for the oxidation of soot particulates, decreasing the conversion temperature and maintaining a small Pt size of 6.99 nm after the sinter-promoting exothermic oxidation. [ABSTRACT FROM AUTHOR]