Highly ordered rutile TiO 2 nanorod arrays (NRAs) are promising architectures in dye-sensitized solar cells (DSCs). However, the efficiency of DSCs based on such photoanodes is still relatively low, largely due to the limited internal surface area. Herein, we report that highly oriented rutile TiO 2 NRAs with film thickness up to $30 mm was developed by a facile hydrothermal method. More importantly, an optimized porous rutile TiO 2 NRAs with a large internal surface area was fabricated on the FTO (fluorine-doped tin oxide) substrate via a secondary hydrothermal treatment and when applied as the photoanodes in DSCs, a record efficiency of 7.91% was achieved. Broader contextOne-dimensional (1-D) single-crystalline rutile TiO 2 nanorod arrays (NRAs) have attracted much attention in various applications due to its unique optoelectronic properties, such as sensors, photocatalysts, electrochromism, ultraviolet photodetectors, solar water splitting, self-cleaning coatings and solar cells. In general, a large surface area is of great signicance in most of its applications that require sufficient reaction sites on the surface of TiO 2 . In our present work, we provide a facile hydrothermal method for preparation of rutile TiO 2 NRAs with a high surface area. Our strategies focused on developing thicker rutile TiO 2 NRAs by proper treatment of the FTO substrates and adopting a hydrothermal etching route for further enhancing its surface area. The selective etching route introduced in our work may become a general method for developing other wide-band semiconductor nanorod/nanotube materials (e.g. ZnO, Nb 2 O 5 , SnO 2 and TiO 2 with other crystal phases) with a large surface area, which would be highly benecial for their applications in solar water splitting, photocatalysts or dyesensitized solar cells. Moreover, such a material provided in this report (i.e. 1-D single-crystalline rutile TiO 2 NRAs) may nd its promising applications in the related energy and environmental applications due to its well-dened porous array structure and large surface area.

The oxide layer spontaneously formed on zinc and an ''electrochemically reduced'' oxide has been characterised by a combination of X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE). The onset of the main electronic absorption, which is directly related to the bandgap, is extracted from the SE measurements. The SE results are compared with simulations on the basis of zinc and bulk zinc oxide optical constant data. Measurements in the ultraviolet and visible (UV-vis) spectral range show the presence of an absorption at B1.8 eV (680 nm) which is unaccounted for from the bulk data, and is likely to originate from intragap energy levels, implicating the presence of surface defects in the layers. Analysis of the Zn LMM Auger peaks in XPS data show the presence of Zn different from bulk zinc and bulk ZnO, attributed to excess Zn in the oxide films. Mid-infrared (IR) ellipsometry shows two peaks around 0.12 and 0.15 eV (1000 and 1200 cm À1 ), which strengthen the assumption of the presence of a locally distorted structure in the oxide layers. Electrochemically reduced samples show a much thinner oxide layer and higher Zn-doping concentration films than samples purely dipped in NaOH solution. Using a self-contained multiple sample SE analysis, estimates of the refractive index and absorption coefficient (i.e., the optical constants) of the oxide films are presented from 1.5-4.4 eV (280 to 810 nm).

An active oxygen species in molten carbonate is the key to elucidate the complex mechanism of the cathode reaction in MCFC. However, under acidic condition of MCFC operation (P CO 2 > 1.01 × 10 4 Pa), the exact chemical state of the active oxygen species remains unclear and is a subject of continuous debates. In this work, we present the first experimental observation of peroxocarbonate/peroxodicarbonate species in acidic molten carbonate by using in-situ Raman spectroscopic technique. The results indicate that the predominant oxygen species (O 2 2-) in basic lithium-rich melts became unstable with the increase of acidity level in the melts and reacted with CO 2 to produce peroxocarbonate or peroxodicarbonate anion. In combination with the result of theoretical calculation, it is deduced that the peroxodicarbonate mechanism is the dominant feature in the cathode reaction path in MCFC.

Sodium tungstate (Na 2 WO 4 ) and hexamethylene tetramine (HMTA) are both eco-friendly corrosion inhibitors. In this work, their synergistic corrosion inhibition effects on reinforcing steel in the simulated polluted concrete pore solution containing Cl − were studied by electrochemical techniques including electrochemical impedance spectroscopy and potentiodynamic anodic polarization curve measurements. The morphologies and compositions of the steel surface were characterized by Electron Micro-Probe Analyzer, X-ray photoelectron spectroscopy, and Raman spectroscopy. The results showed that the serious steel corrosion took place in the solution with pH 11.00 and 0.5 M NaCl. However, a stable passive region occurred in the anodic polarization curve of the steel and its corrosion current density decreased dramatically after addition of a mixed inhibitor with 0.01 M Na 2 WO 4 and 0.01 M HMTA to the solution. The inhibition efficiency of the mixed inhibitor reached 97.1%. The surface analyses revealed that a protective composite film was formed on the steel in the solution with the mixed inhibitor, which indicated that the mixed inhibitor had a synergistic inhibition effect on the steel corrosion. Our study also indicated that the mixed inhibitor could effectively control corrosion of the reinforcing steel in cement mortar.Reinforcing steel in concrete is normally protected from corrosion by the passive film formed on its surface under high alkaline conditions of concrete. However, the passivity of the reinforcing steel may be destroyed and corrosion take place while aggressive species from the environment such as Cl − , CO 2 , SO 2 , etc., reach the steel-concrete interface through the porous concrete. 1-4 The damage of reinforced concrete structures and economic losses caused by reinforcing steel corrosion are still serious problems. Hence, many techniques have been developed to protect reinforcing steel from corrosion. The application of corrosion inhibitors is one of the most practical methods to control the corrosion of reinforcing steel. 5-7 In recent years, increasing attention has been paid to the environment-friendly corrosion inhibitors and natural products such as plant extracts, amino acids, some inorganic salts, proteins and bio-polymers. [8][9][10][11][12][13][14][15][16][17][18][19] Tungstate has been extensively studied in the protection of iron as an environmental-friendly anodic type inorganic corrosion inhibitor, 20-27 and is one of the most effective corrosion inhibitor. However, tungstate is not feasible to be used alone for corrosion protection of carbon steel due to its low oxidizing ability, high cost and low efficiency at a low concentration. Therefore, many co-inhibitors are used, such as polyaspartic acid, 28-30 metaborates and metaphosphates, 22,24,31 sodium silicate, 27 sodium tartrate, 32 phosphates and zinc salts. 26 The compounds of tungstate synergistically in combination with small molecule compounds (such as amine) for the protection of steel are supposed to be good corrosion inhibi...

Adsorbed silver nanoparticles were prepared by means of electron beam evaporation of silver on ultra thin Si-supported heptadecafluoro-1-decene plasma polymer films and self-assembled heptadecafluorodecyl-trimethoxysilane monolayers. The morphology of the silver nanoparticles, characterized by their size, size distribution, shape and interparticle separation, was observed to depend on the type, chemical composition and surface energy of the sub-layer as well as the amount of silver deposited. Field emission-scanning electron microscopy was used to study the change in the morphology of the silver nanoparticles as a function of the preparation parameters. The silver nanoparticles on the ultra thin plasma polymer films demonstrated a much smaller and narrower size distribution due to the cross-linking within the film, which more effectively hinders the penetration of silver through the film in comparison to the self-assembled monolayers. Moreover, the optical properties of the resulting silver nanoparticles on the ultra thin fluorocarbon plasma polymers and their correlation to size and size distribution were investigated by spectroscopic ellipsometry in the wavelength range between 300 and 800 nm.

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