Modified TiO2 Film Research Articles

SYNTHESIS OF Ag-MODIFIED TiO2 SOL-GEL FILMS AND ITS APPLICATION AS PHOTOCATALYSTS FOR METHYLENE BLUE DEGRADATION

In the study, the photocatalytic activity of TiO2 films that are created by dip-coating from a sol that contained titanium (IV) isopropoxide, monoethanolamine, and 2-methoxyethanol is demonstrated. Through photo-fixation of Ag (I) ions with varied concentration (10-2 - 10-4 M) in the water phase under UV illumination, the films are subsequently surface-modified with Ag co-catalyst layers. Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Ultraviolet-Visible (UV) Spectroscopy, and Electron Paramagnetic Resonance (EPR) techniques are used to physically characterize the samples. Results reveal that the modification of the co-catalyst had no impact on the thickness and porosity of the films. In addition, the study show that the modified TiO2 films had increased photocatalytic activity. All the characterization methods used have shown the formationof surface - bound Ag (I) species and metallic silver nanoclusters. By measuring the Methylene Blue (MB) dye degradation under UV light illumination, as - prepared and Ag -modified TiO2 films are evaluated for their photocatalytic activity, and the impact of the silver precursor concentration during photo-fixation is investigated.The highest catalytic activity is seen for films that have been modified at a concentration of Ag (I) of 10-2 M. Ordered from highest to lowest, the MB photodegradation rate constants are TiO2 < TiO2 /Ag, 10-4 < TiO2 /Ag, 10-3 < TiO2 / Ag, 10-2.

Transition metals Fe3+, Ni2+ modified titanium dioxide (TiO2) film sensors fabricated by CPT method to sense some toxic environmental pollutant gases

The present investigation deals synthesis of undoped TiO2, Ni2+ doped TiO2, and Fe3+ doped TiO2 nanoparticles by low-cost co-precipitation (CPT) method. The thick film sensors of all the fabricated modified TiO2 nanoparticles were designed by a screen printing strategy. The prepared thick film sensors were characterized by various sophisticated techniques. The structural parameters of undoped TiO2 and modified TiO2 film sensors were characterized by X-Ray Diffraction (XRD) which confirmed anatase phase of TiO2 lattice. The surface morphological properties of all the prepared materials were confirmed by means of scanning electron microscope (SEM). The energy dispersive spectroscopy (EDS) confirms the elemental composition of all the prepared materials. High-Resolution Transmission Electron Microscopy (HR-TEM) was utilized to investigate the crystal lattice of fabricated TiO2 material. The HR-TEM results revealed the anatase phase crystal morphology of prepared material. The prepared TiO2 materials were also characterized by means of X-Ray photoelectron spectroscopy (XPS) to confirm the surface doping, specific biding energies, chemical states and elemental composition of modified TiO2 materials. The Brunauer–Emmett–Teller (BET) study was carried to investigate the specific surface area of all the prepared sensors. The Fe3+ doped TiO2 sensor found with enhanced surface area (83.10 ​m2/g) in comparison to Ni2+ doped TiO2 and bare TiO2 (67.34 ​m2/g). All the prepared materials were investigated for gas sensing characteristics. The NO2, SO2, and CO2 gases were investigated for all the prepared sensors. The reusability test confirms that the Fe3+ doped TiO2 is reproducible and stable sensor for long time repeated sensing of SO2 and NO2 vapors. Importantly, Fe3+ doped TiO2 sensor showed rapid response and recovery towards SO2 and NO2 vapors.

TiO2 composite films on different substrates with enhanced visible light photocatalytic performance

For the sake of improving the photocatalytic performance of TiO2, we prepared the B/Ag/Fe tridoped TiO2 films on common glass and stone substrates by the sol–gel method. In this work, the optical absorption, recombination of photogenerated electrons (e−) and holes (h[Formula: see text]), crystal types, thermal stability, composition, specific surface area and photocatalytic activity of the modified TiO2 films were investigated. The results indicated that B/Ag/Fe tridoping not only enhanced the absorption of visible light by TiO2, but inhibited the recombination of electron–hole (e−/h[Formula: see text]) pairs. The tridoping also promoted the formation of anatase and prevented the transformation of anatase to rutile at high temperature. The composite TiO2 has a large specific surface area, about three times that of pure TiO2. The photocatalytic activity of the TiO2 films were evaluated by methyl green (MG) and formaldehyde degradation. In all samples, the B/Ag/Fe tridoped TiO2 film exhibited the highest degradation rate of MG under both ultraviolet and visible light irradiation. The improvement of photocatalytic performance of TiO2 films is due to the synergistic effect of the B/Ag/Fe tridoping, which enhances the absorption of visible light and prolongs the lifetime of e−/h[Formula: see text] pairs and facilitates transfer of interface charge.

Synthesis and Modification of TiO2 nanostructured Materials for Energy Storage

Increasing energy demand is inexorably linked to the need for efficient energy storage techniques. For practical applications, it is highly desirable to decrease the size of electrical components and to increase the storage capacities while maintaining power, stability, and charging-discharging speeds. Much focus has been directed towards the development of supercapacitors. These are often fabricated from carbonaceous or metal oxide materials with high surface areas to maximize electrode/electrolyte interactions. The use of nanostructured TiO2 electrodes has been explored for this application due to their low cost, high stability, and highly tunable morphology.Here we present the fabrication of nanostructured TiO2 films via a facile anodic process. Characterization of the films was carried out by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. Electrochemical reduction of the formed TiO2 film was further performed to increase its capacitance, which was confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. The performance of the symmetric capacitor constructed with the modified TiO2 films will be presented.

Surface modification of TiO2 for photoelectrochemical DNA biosensors

AbstractA photoelectrochemical (PEC) DNA biosensor is developed using surface‐modified TiO2 nanoparticles (NPs) as a sensitive transducer. Different catecholates and gallates are used as sensitizers for TiO2 NPs. The molecules are adsorbed on TiO2 via the catecholate type bonding mechanism to enhance light absorption in the visible range. The adsorbed molecules act as charge transfer mediators and enhance photocurrent. Despite the similar bonding mechanism of the molecules, the TiO2 NPs exhibit significant differences in photocurrent. The modified TiO2 films showed photocurrent increase in the order: 3,4‐dihydroxy‐L‐phenylalanine < 2,3,4‐trihydroxybenzoic acid < 3,4‐dihydroxybenzoic acid < 2,3,4‐trihydroxybenzaldehyde < 3,4‐dihydroxyphenylacetic acid < 3,4‐dihydroxybenzaldehyde < caffeic acid. Testing results provide an insight into the influence of the structure and properties of the organic molecules on their adsorption and photocurrents of modified TiO2 films. The TiO2 NPs modified with caffeic acid are used for the fabrication of PEC DNA biosensor by forming photoelectrodes and immobilizing probe single‐stranded DNA on their surface. The caffeic acid‐modified TiO2‐based photoelectrodes offer the required signal magnitude to distinguish between complementary and non‐complementary DNA sequences in the 100 nM–1 pM DNA concentration range and with a limit of detection of 1.38 pM, paving the way towards PEC DNA sensing.

Synthesis of eosin modified TiO2 film with co-exposed {001} and {101} facets for photocatalytic degradation of para-aminobenzoic acid and solar H2 production

Owing to the increasing photosensitivity and DNA damage properties of para-aminobenzoic acid (PABA), concerns have been raised over the exposure of humans to PABA. Solar light-driven photocatalysis (SPC) provides a promising solution for the effective removal of organic pollutants especially when directed towards sulfate radical (SO4−) production. Herein, we have developed a sulfite-enhanced SPC using Eosin-Y sensitized TiO2/Ti film as a photocatalyst. The removal efficiency of PABA was enhanced by coupling Eosin-Y with TiO2/Ti film as revealed from 23.6 and 48.9 % PABA degradation by reference-TiO2/solar and Eosin-TiO2/solar, respectively. The apparent rate constant of PABA degradation by Eosin-TiO2 was improved by 4.7 times in presence of 5 mM sulfite. Interestingly, Eosin-TiO2 showed appreciable H2 production rate under visible light illumination. Solar/sulfite/Eosin-TiO2 system is a promising technology for environmental sustainability by using the renewable solar energy and air pollutants since sulfite is a waste from flue gas desulfurization process.

Efficient photoelectrochemical water splitting of stainless steel electrocatalyst modified TiO2 films

abstract Stainless steel (ST) is widely used in many different fields due to its low cost and excellent stability. However, the electrocatalytic property of ST film for water oxidation, especially combined with TiO 2 photoanode, is seldom investigated. In this paper, we report a one-step sputtering strategy to synthesize ST film electrocatalysts on TiO 2 film in order to boost the oxygen evolution reaction (OER) in water splitting. Compared to pristine TiO 2 electrode, the ST modified electrode achieved a largely enhanced PEC performance. Such enhancement could be manipulated in an optimal manner when the ST film thickness was further varied, where the 80 nm ST modified TiO 2 (ST-80-TiO 2 ) showed the lowest overpotential of 132 mV, with the highest photocurrent density enhancements of nearly 18-fold and 11-fold under dark and simulated sunlight illumination, respectively. This facile and effective decoration approach makes it possible to design ST electrocatalyst-semiconductor structures for other general photoanode improvements.

Colorful nanostructured TiO2 film with superhydrophobic–superhydrophilic switchable wettability and anti-fouling property

Superhydrophobic nanostructured TiO2 film was successfully fabricated on the Ti plate by anodic oxidation and lauric acid modification. By varying the applied voltage, TiO2 films with various nanostructures and colors were prepared. The water contact angles (WCA) on the modified TiO2 film increased as the applied voltage increased, and the highest WCA on the TiO2 nanovesuvianite film was about 161.23°. When the applied voltage was 5 V and 20 V, the obtained TiO2 nanopores and TiO2 nanotubes could be used to build two improved Cassie models for designing superhydrophobic surface. Moreover, the superhydrophobic TiO2 film showed good anti-fouling property, particularly it could maintain superhydrophobicity both when immersed in and taken out from the organic solvents. The superhydrophobic film could be changed into superhydrophilic under ultraviolet (UV) irradiation, and the superhydrophilic film recovered to hydrophobic or superhydrophobic gradually at 60 °C in the dark. Additionally, the superhydrophilic film showed underwater superoleophobicity, which exhibited excellent anti-fouling property by degrading the oil under UV light.

Fabrication of superhydrophobic TiO2 quadrangular nanorod film with self-cleaning, anti-icing properties

Abstract Superhydrophobic TiO2 quadrangular nanorod film was fabricated by hydrothermal reaction and stearic acid modification. X-ray diffractometer and Fourier transform infrared spectrometer were employed to characterize the surface crystal structures and chemical compositions of the superhydrophobic TiO2 film, respectively. The effects of the titanium source (titanium tetraisopropoxide (TTIP)) amount and reaction time on the morphology and wettability of the TiO2 film were studied by scanning electron microscope and contact angle meter. The results show that the diameter of the TiO2 quadrangular nanorods increases and then the water contact angle on modified TiO2 film decreases with the increase of the reaction time and TTIP amount. Moreover, when the TTIP amount is 0.3 mL and solvent is 30 mL, the wetted state of the superhydrophobic TiO2 film surface conforms to an improved Cassie model. Besides, the superhydrophobic TiO2 film shows good low adhesion, self-cleaning and anti-icing properties. Particularly, the anti-icing property decreases with the increase of the reaction time and TTIP amount.

Enhanced performance of planar perovskite solar cells based on low-temperature processed TiO2 electron transport layer modified by Li2SiO3

Planar perovskite solar cells based on Li2SiO3 modified TiO2 electron transport layer are fabricated by one-step method. Here the Li2SiO3 modified TiO2 films are prepared by a simple soaking process at 65 °C. The effect of Li2SiO3 modification on the photoelectric properties of TiO2 films and devices has been systematically investigated. Compared to the reference TiO2, the modified TiO2 demonstrates better characteristics such as better surface wetting properties of perovskite precursor, enhanced electron mobility and reduced electron trap state density, which contribute to the favorable photovoltaic performance. At the optimized process, the device based on the modified TiO2 film yields a champion power conversion efficiency of 18.67%, being much higher than 14.78% of the reference device. The improved performance is primarily attributed to the promoted charge transport and reduced charge recombination in the modified electron transport layer. This work provides a simple route to obtain efficient planar perovskite solar cells by low-temperature process, which will be compatible with flexible plastic substrates in future practical applications.

Enhanced photoelectrochemical performance of iron and carbon self-doped TiO2 photoanodes modified with nitrogen

The photoelectrochemical performance and the semiconducting properties of iron, carbon and nitrogen modified TiO2 films prepared by a sol-gel method and deposited on 304 stainless steel (304SS) plates by a dip-coating technique were studied. Iron and carbon co-doped films were prepared for comparative purposes. The morphological, structural, optical and photoelectrochemical properties of the as-prepared materials were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy, grazing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), and open circuit potential (OCP), linear sweep voltammetry and Mott-Schottky (M-S) analyses. FESEM images of the tri-doped films showed the formation of a homogenous surface with one layer deposited on 304SS, while a cracked surface was observed when the number of layers was increased to three. GIXRD indicated the presence of the anatase phase in the films. XPS showed the doping of the TiO2 with nitrogen, iron and carbon. DRS showed an adsorption edge displacement from 3.00 eV for TiO2 films with one layer to 2.75 eV after nitrogen modification. OCP and M-S measurements obtained in 0.1 M HClO4 at pH 1 showed that the flat band potential tends to be more negative after nitrogen modification, therefore increasing the charge carrier density and improving the photoelectrochemical performance. Furthermore, decreasing the number of layers increases the electrochemical efficiency due to the diminution of the grain boundaries. The synergistic effect promoted by iron, carbon and nitrogen introduces the tri-doped TiO2 films as an alternative for photoelectrochemical applications under visible light illumination.

Long-Term Photoelectrochemical Cathodic Protection by Co(OH)2-Modified TiO2 on 304 Stainless Steel in Marine Environment

The long-term photoelectrochemical cathodic protection by Co(OH)2-surface modified TiO2 of anatase nanotubes and rutile type, prepared by anodic oxidation has been studied in aqueous 3.5 wt% NaCl solution. Electrochemical measurements have been used to evaluate the photoelectrochemical protective properties of both Co(OH)2-modified TiO2 coupled with 304 stainless steel in 3.5 wt% NaCl solution under illumination and in the dark. Morphologies, crystal structures, surface compositions, and light response range of both Co(OH)2-surface modified TiO2 films before and after immersion were characterized, respectively, by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometry. The results show that the photogenerated electrode potential of both types of TiO2 films modified with Co(OH)2 is more negative affording protection of 304 stainless steel than that of the non-modified TiO2 under illumination. These TiO2 films provide a long period (12 h) of protection. The anatase-TiO2 nanotube film always shows a better protection performance than rutile-TiO2 film.

A one-step preparation and enhanced electrochemical properties of C-TiO2 composite films

In order to improve the capacitive properties of TiO2 materials for supercapacitors, the carbon-modified TiO2 (denoted as C-TiO2) composite films was synthesized by gas thermal penetration of pure Ti plate with methanol as the drop agent under the temperature of 550°C. The structure and composition of C-TiO2 was investigated by SEM, XRD, RAMAN, XPS and XANES. The electrochemical performance of C-TiO2 was evaluated by electrochemical impedance spectra (EIS), cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) tests. Results show that the film is composed of a large amount of rutile TiO2 and a little anatase TiO2, and meantime the carbon is deposited on the film through the methanol decomposition during the gas thermal penetration, which greatly influences the electrochemical properties of the composite films. The prepared C-TiO2 yields the largest specific capacities of 47.46mCcm−2 at the scan rate of 10mVs−1 based on the CV curves, and 7.35mCcm−2 at the current density of 0.075mAcm−2 based on the galvanostatic charge/discharge curves, which compares favorably with many other similar modified TiO2 film materials reported nowadays. The excellent large charge storage properties of C-TiO2 films are attributed to the deposition of a certain amount of graphitized carbon and organic carbon containing hydroxyl groups and carbanyl groups and the formation of Ti3+ in the form of TiO1.5 under methanol reductive atmosphere be means of the improvement of the pseudocapacitance property and the conductivity of the composite films.

Wastewater treatment by sonophotocatalysis using PEG modified TiO2 film in a circular Photocatalytic-Ultrasonic system

TiO2 photocatalyst film recently has been utilized as the potential candidate for the wastewater treatment, due to its high stability and low toxicity. In order to further increase the photocatalytic ability and stability, different molecular weight of polyethylene glycol (PEG) were used to modify TiO2 structure to synthesize porous thin film used in the developed Photocatalytic-Ultrasonic system in this work. The results showed that PEG2000 modified TiO2 calcinated under 450°C for 2h exhibited the highest photocatalytic activity, attributed to the smallest crystallite size and optimal particle size. Over 95.0% of rhodamine B (Rh B) was photocatalytically degraded by optimized PEG2000-TiO2 film after 60min of UV irradiation, while only about 50.8% of Rh B was decolored over pure TiO2 film. Furthermore, optimized PEG2000-TiO2 film was used in a circular Photocatalytic-Ultrasonic system, and the obtained synergy (0.6519) of sonophotocatalysis indicated its extremely high efficiency for Rh B degradation. In this Photocatalytic-Ultrasonic system, larger amount of PEG2000-TiO2 coated glass beads, stronger ultrasonic power and longer experimental time could result to higher degradation efficiency of Rh B. In addition, repetitive experiments showed that about 97.2% of Rh B were still degraded in the fifth experiment by sonophotocatalysis using PEG2000-TiO2 film. Therefore, PEG2000-TiO2 film used in Photocatalytic-Ultrasonic system has promising potential for wastewater treatment, due to its excellent photocatalytic activity and high stability.

Tailoring of the TiO2 film by H2SO4 treatment and UV-irradiation for improving anticoagulant ability and cell compatibility

Event Abstract Back to Event Tailoring of the TiO2 film by H2SO4 treatment and UV-irradiation for improving anticoagulant ability and cell compatibility Jiang Chen1, Yuzhen Liao1, Linhua Li1, Ping Yang1, Hong Sun1 and Nan Huang1 1 Ministry of Education, Southwest Jiaotong University, Key Laboratory for Advanced Technologies of Materials,, China Introduction: Good anticoagulant ability and good endothelial cells (ECs) compatibility were important to the cardiovascular implants. Recently, UV irradiation has been reported to easily improve the anticoagulant ability[1], which was related to the changes in the nature of the TiO2 film caused by the photo-generated ROS[2]. On the other hands, H2SO4 treatment has been reported to improve the cell compatibility, which was related to the enhancement of the positive charge of the TiO2 film[3]. In this study, the TiO2 films were treated successively with H2SO4 and the UV irradiation, then the materials detection and the biological detection was performed to determine: (1) whether the H2SO4 and the UV treatment improving the anticoagulant and the cell compatibility of the TiO2 film at the same time; (2) the relationship between the anticoagulant ability /cell compatibility and the changes in the nature of the TiO2 film. Materials and methods: As shown in Fig. 1, TiO2 film on Si substratum was firstly treated by H2SO4 (67 wt %) in 120 °C for 5min; after that, the TiO2 film was UV-irradiated for 1h with UV light intensity of 16 mW/cm2 (λ = 365nm). The physicochemical properties of modified TiO2 surface were characterized. The anticoagulant ability and the cell compatibility were also evaluated. Fig. 1. Preparation of H2SO4-treated and UV-irradiated TiO2 film Results and Discussion: According to Fig.2, UV irradiation significantly shifted the shoulder peaks at about 288 eV to a higher bonding energy, indicating the oxidation of the hydrocarbon contaminants which adsorbed on the TiO2 surface. H2SO4 treatment slightly shifted the shoulder peaks to a higher bonding energy (Fig.2A), indicating the slightly oxidation of the hydrocarbon contaminants. Both UV irradiation and H2SO4 treatment reduced the atomic percentages of carbon on the TiO2 films and induced the increasing of positive charge. However, the H2SO4 treatment induced more positive charge on the TiO2 surface than UV irradiation (Fig. 2B). The results of platelet adhesion and fibrinogen adsorption showed the UV irradiation significantly improved the anticoagulant ability of TiO2 films by suppressing the fibrinogen adsorption and platelet adhesion. On the other hand, the H2SO4 improved the anticoagulant ability of TiO2 films slightly, which could be related to the slightly oxidation of the hydrocarbon contaminants adsorbed on the TiO2 surface (Fig. 2C). The results of ECs and Macrophages culture revealed that the H2SO4 treatment strongly enhanced the cellular adhesion and proliferation, which could be related to the increasing of the positive charge on the H2SO4-treated TiO2 surface (Fig 2D and E). According to the results above, the UV-irradiated and H2SO4-treated TiO2 films showed good anticoagulant ability and cell compatibility. Fig. 2. The change of the physicochemical properties and the biocompatibility of modified TiO2 films: (A) The close-up view of the XPS C 1s peak. (B) The change of the atomic percentage of carbon and the surface charge. (C) Anticoagulant ability, (D) ECs adhesion. (E) Macrophages adhesion. Conclusions: This study provides a novel and facile construction method for improving both the anticoagulant ability and cell compatibility of TiO2 film. The improving of the anticoagulant ability could be related to the oxidation of the adsorbed hydrocarbon contaminants which could be caused by the photo-generated ROS. On the other hand, the improving of the cell compatibility induced by the H2SO4 treatment could be related to the increasing of the positive charge of the TiO2 surface, which could be caused by the degradation of the adsorbed hydrocarbon contaminants on the TiO2 surface. The National Natural Science Founda-tion of China (No. 31570963); The National Natural Science Founda-tion of China (No. 81401522)

Superhydrophilic TiO2 thin film by nanometer scale surface roughness and dangling bonds

A remarkable enhancement in the hydrophilic nature of titanium dioxide (TiO2) films is obtained by surface modification in DC-glow discharge plasma. Thin transparent TiO2 films were coated on glass substrate by sol–gel dip coating method, and exposed in DC-glow discharge plasma. The plasma exposed TiO2 film exhibited a significant change in its wetting property contact angle, which is a representative of wetting property, has reduced to considerable limits 3.02° and 1.85° from its initial value 54.40° and 48.82° for deionized water and ethylene glycol, respectively. It is elucidated that the hydrophilic property of plasma exposed TiO2 films dependent mainly upon nanometer scale surface roughness. Variation, from 4.6nm to 19.8nm, in the film surface roughness with exposure time was observed by atomic force microscopy (AFM). Analysis of variation in the values of contact angle and surface roughness with increasing plasma exposure time reveal that the surface roughness is the main factor which makes the modified TiO2 film superhydrophilic. However, a contribution of change in the surface states, to the hydrophilic property, is also observed for small values of the plasma exposure time. Based upon nanometer scale surface roughness and dangling bonds, a variation in the surface energy of TiO2 film from 49.38 to 88.92mJ/m2 is also observed. X-ray photoelectron spectroscopy (XPS) results show change in the surface states of titanium and oxygen. The observed antifogging properties are the direct results of the development of the superhydrophilic wetting characteristics to TiO2 films.

Photocatalytic degradation of formaldehyde by nanostructured TiO2 composite films

Interest in the photocatalytic oxidation of formaldehyde from contaminated wastewater is growing rapidly. The photocatalytic activity of the nanocrystalline Fe3+/F− co-doped TiO2–SiO2 composite film for the degradation of formaldehyde solution under visible light was discussed in this study. The films were characterised by field emission scanning electron microscopy (FE-SEM) equipped with energy-dispersive spectroscopy, X-ray diffraction (XRD), BET surface area, UV–Vis absorption spectroscopy, and photoluminescence spectroscopy. The FE-SEM results revealed that the Fe3+/F− co-doped TiO2–SiO2 film was composed of uniform round-like nanoparticles or aggregates with the size range of 5–10 nm. The XRD results indicated that only the anatase phase was observed in the film. Compared with a pure TiO2 film and a singly modified TiO2 film, the Fe3+/F− co-doped TiO2–SiO2 composite film showed the best photocatalytic properties due to its strong visible light adsorption and diminished electrons-holes recombination.

Enhanced photoelectrochemical and photocatalytic activity of WO3-surface modified TiO2 thin film.

Development of nanostructured photocatalysts for harnessing solar energy in energy-efficient and environmentally benign way remains an important area of research. Pure and WO3-surface modified thin films of TiO2 were prepared by magnetron sputtering on indium tin oxide glass, and photoelectrochemical and photocatalytic activities of these films were studied. TiO2 particles were <50 nm, while deposited WO3 particles were <20 nm in size. An enhancement in the photocurrent was observed when the TiO2 surface was modified WO3 nanoparticles. Effect of potential, WO3 amount, and radiations of different wavelengths on the photoelectrochemical activity of TiO2 electrodes was investigated. Photocatalytic activity of TiO2 and WO3-modified TiO2 for the decolorization of methyl orange was tested.Graphical abstractWO3-surface modified TiO2 film showing better photocatalytic and photoelectrocatalytic activity.

A robust, anti-acid, and high-temperature–humidity-resistant superhydrophobic surface of wood based on a modified TiO2 film by fluoroalkyl silane

A two-step method containing low-temperature hydrothermal synthesis with TiO2 precursor solution and subsequent modification with fluoroalkyl silane on wooden substrates was investigated. Scanning electron microscopy (Scanning electron microscope) images showed that the TiO2-treated wood substrate was covered with uniform TiO2 particles, which generated a roughness on the wood surface favoring the formation of the superhydrophobic surface, and the decoration of (heptadecafluoro-1,1,2,2-tetradecyl)trimethoxysilane on TiO2-based wood surface acted as a crucial role in improving the repellency toward water. The superhydrophobic wood surface with the water contact angle (WCA) of 152.9°, maintained superhydrophobic property with the WCA larger than 150° after immerse in 0.1M hydrochloric acid solution for one week, irradiating under UV light for 24h, or boiling at 150°C for 10h. The prepared wood surface showed multi-functions including super repellency toward water, anti-acid, and high-temperature–humidity-resistant. On the basis of the results, the functional coating on the wood surface provided an enlarged field of the wood works, such as historic structure protection.

Template free titiania photoanodes modified with carbon black or multi-wall carbon nanotubes: Thermal treatment at low and high temperature for the fabrication of quasi-solid state dye sensitized solar cells

A simple procedure was developed to prepare modified titiania (TiO2) photoanodes for dye sensitized solar cells at low and high temperature in order to improve overall cell efficiency. Modification of TiO2 films achieved by the incorporation of either carbon black powder (CBP) or multi-wall carbon nanotubes (MWCNTs). A small quantity of titanium alkoxide was added in a dispersion of titiania (TiO2) powder consisting of nanoparticles at room temperature, which after alkoxide׳s hydrolysis helps to the connection between titiania (TiO2) particles and to the formation of mechanically stable relatively thick films on conductive glass substrates. The absence of surfactant allowed us to prepare films at relatively low temperature (~100°C), while the effect of sintering at a higher temperature (500°C) was also studied. The structural properties of the films were examined with porosimetry method and microscopy analysis. Better electrical results were obtained for the MWCNT (0.1wt%) modified TiO2 films, with 3.14% and 4.68% conversion efficiencies under 1sun illumination after treatment at 100°C and 500°C, respectively. The enhancement in photocurrent for MWCNT-TiO2 films compared to pure TiO2 films is attributed to the improved interconnectivity between TiO2 nanoparticles, which further improved the electron transport through the film. For carbon doped CBP-TiO2 cells, lower efficiencies were observed compared to pure TiO2.