Anodic self-organized TiO2 nanostumps are formed and exploited for self-ordering dewetting of Au–Ag sputtered films. This forms ordered particle configurations at the tube top (crown position) or bottom (ground position). By dealloying from a minimal amount noble metal, porous Au nanoparticles then formed, which, when in crown position, allow drastically improved photocatalytic H2 production compared with produced by conventional processes.

Noble metal dewetting on self-organized TiO₂ nanotubes – nanoscopic design of photocatalysts towards green H₂ generation.

Electrochemical anodization of low-concentration (0.02–0.2 at% Au) TiAu alloys in a fluoride electrolyte leads to self-organized TiO2 nanotubes that show controllable, regular situ decoration with elemental Au nanoclusters ≈5 nm diameter. The degree self-decoration can be adjusted by the concentration alloy and time. Such particle decorated tubes high activity for photocatalytic H2 production from ethanol solutions. As service our authors readers, this journal provides supporting information...

Abstract Separation and transfer of photogenerated charge carriers are key elements in designing photocatalysts. TiO 2 numerous geometries has been for many years the most studied photocatalyst. To overcome kinetic limitations achieve swift transfer, widely investigated with cocatalysts that commonly randomly placed nanoparticles on a surface. The poor control over cocatalyst placement powder technology approaches can drastically hamper photocatalytic efficiencies. Here contrast it is shown...

Abstract Solid‐state dewetting is the heat‐induced agglomeration of thin metal films into defined nanoparticles (NPs). Dewetted Pt are investigated on F‐doped SnO 2 (FTO) substrates as model binder‐free electrodes for hydrogen evolution reaction (HER). Dewetting particles exposes FTO substrate and metal/support (Pt‐FTO) contact line. Despite decrease in electrochemical surface area (ECSA) upon dewetting, dewetted NPs show a >3‐fold increase ECSA‐normalized HER activity compared to...

A little dopey: Ta-doped titania (TiO2) nanotube (NT) arrays can be grown by electrochemical anodization onto low-Ta-concentration (0.03-0.4 at % Ta) Ti-Ta alloys. Under optimized conditions (0.1 Ta, annealing 650 °C and 7 μm thickness), TiO2 NT show a significantly enhanced activity in photoelectrochemical water splitting under simulated sunlight (see figure).

Gleichförmigkeit perfektioniert: Ein hochorientierter Aunp@TiO2-Photokatalysator wurde durch selbstorganisierende Anodisierung eines Ti-Substrats und anschließende Entnetzung Gold-Dünnfilms erhalten. Das Ergebnis: genau ein Au-Nanopartikel (np) pro TiO2-Nanokavität. Solche Anordnungen sind hocheffiziente Photokatalysatoren für die Wasserstofferzeugung aus Ethanol. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are...

Photocatalytic $H_2$ evolution reactions on pristine TiO$_2$ is characterized by low efficiencies due to trapping and recombination of charge carriers, a sluggish kinetics electron transfer. Noble metal (mainly Pt, Pd, Au) nanoparticles are typically decorated as cocatalyst the surface reach reasonable photocatalytic yields. However, owing high cost noble metals, alternative cocatalysts being developed. Here we introduce an approach fabricate efficient free platform for based alloyed NiCu...

In the present work we introduce a technique to form photocatalyst, based on Pt nanoparticles suspended over mouth of TiO2 nanotubes. These structures are obtained by decoration top end highly ordered nanotubes with web nanofibrils, followed sputter deposition minimum amount Pt. A subsequent thermal dewetting step forms 3-6 nm-sized along nanofibrils. structures, when compared conventional techniques nanotubes, show strongly enhanced photocatalytic H2 evolution efficiency.

Cu- or Ni-decorated semiconductors represent a potential low-cost alternative to noble-metal-modified photocatalysts. Even more effective are bimetallic NiCu nanoparticles, which can provide remarkable photocatalytic H2 evolution enhancement compared single-element Cu Ni systems. The main concern of such alloyed co-catalysts is their activity with respect alteration elemental composition and oxidation state over reaction time. Ex situ characterization techniques controversial interpretations...

Abstract The engineering of the electron transport layer (ETL)/light absorber interface is explored in perovskite solar cells. Single‐crystalline TiO 2 nanorod (NR) arrays are used as ETL and methylammonium lead iodide (MAPI) light absorber. A dual surface modification investigated, namely by a TiCl 4 treatment combined with subsequent PC 61 BM monolayer deposition, effects on device photovoltaic performance were evaluated respect to single modifications. Under optimized conditions, for...

Biochar nanoparticles (BC NPs), produced by low temperature pyrolysis (350 °C) of microalgae (Nannochloropsis sp.) and nutshells, are proposed as low-cost sustainable co-catalysts to promote the photocatalytic activity TiO2 nanotube (NT) arrays towards degradation methylene blue (MB) used an organic pollutant model molecule. BC NPs (size < 25 nm) were obtained treating bulk (i.e., biomass after pyrolysis) sonication–centrifugation cycles in a water solution. The filtered dispersion was...

The electrochemical synthesis of

Electrochemical formation of self-organized TiO2 nanotube layers has been a highly active research field for more than 10 years. In the present manuscript we investigate two distinctly different anodic morphologies, 'single walled' and 'double tubes, which are formed mainly depending on nature anodization electrolyte. While widest used electrolytes ethylene glycol (EG) based, forming double walled structures, tubes in dimethyl sulfoxide (DMSO) based show single tube morphology. Here provide...

In the current work, we present a new self-organizing anodization approach of metallic Sn layers to obtain vertically aligned tin oxide nanochannel structures. For this, use sulphide-containing electrolyte and set optimized anodizing parameters. The resulting high aspect ratio morphologies can be converted into crystalline SnO2 by temperature annealing show highly promising H2 sensing properties. We that these anodic operate at relatively low temperatures (∼80 °C), detecting concentrations...

The least is the best. We introduce a technique to strongly reduce Pt use for photocatalytic hydrogen generation from TiO2 nanotubes. By site-selectively depositing thin layers of only at mouth nanotubes and by subsequent thermal dewetting step, we achieve an outstanding improvement with minimal amounts co-catalyst.

We use free-standing TiO2 nanotube membranes that are transferred onto FTO slides in front-side illuminated dye-sensitized solar cells (DSSCs). investigate the key parameters for cell arrangement of self-ordered anodic layers on substrate, namely influence annealing procedure DSSC light conversion efficiency. The results show using an optimal temperature profile can significantly enhance efficiency (in our case η = 9.8%), as it leads to a markedly lower density trapping states tube oxide,...

We investigate the co-catalytic activity of PtCu alloy nanoparticles for photocatalytic H2 evolution from methanol–water solutions. To produce photocatalysts, a few-nanometer-thick Pt–Cu bilayers are deposited on anodic TiO2 nanocavity arrays and converted by solid-state dewetting via suitable thermal treatment into bimetallic nanoparticles. X-ray diffraction (XRD) photoelectron spectroscopy (XPS) results prove formation nanoalloys that carry shell surface oxides. absorption near-edge...