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Abstract: A facile method was used to prepare hollow mesoporous TiO2 and Au@TiO2 spheres using polystyrene (PS) templates. Au nanoparticles (NPs) were simultaneously synthesized and attached on the surface of PS spheres by reducing AuCl4− ions using sodium citrate which resulted in the uniform deposition of Au NPs. The outer coating of titania via sol‐gel produced PS@Au@TiO2 core–shell spheres. Removing the templates from these core–shell spheres through calcination produced hollow mesoporous and crystalline Au@TiO2 spheres with Au NPs inside the TiO2 shell in a single step. Anatase spheres with double Au NPs layers, one inside and another outside of TiO2 shell, were also prepared. Different characterization techniques indicated the hollow mesoporous and crystalline morphology of the prepared spheres with Au NPs. Hollow anatase spheres with Au NPs indicated enhanced harvesting of visible light and therefore demonstrated efficient catalytic activity toward the degradation of organic dyes under the irradiation of visible light as compared to bare TiO2 spheres. [ABSTRACT FROM AUTHOR]

Abstract: Well-aligned TiO2 nanotube (NT) arrays with multilayer architecture were fabricated using periodic anodization method. Periodic pulses, consisting of high and low voltages, were applied to fabricate TiO2 NTs with periodically changing morphology. The approach was simple and allowed for better control in the continuous fabrication of various multilayer TiO2 NT arrays. These TiO2 NT arrays with multilayer morphologies showed a better photocatalytic property than smooth TiO2 NTs, and it is expected to have extensive applications in the fields of selective filters, targeted delivery, solar cells, and photocatalysis. [Copyright &y& Elsevier]

Abstract: A novel solid-phase microextraction (SPME) fiber is fabricated through the anodization of Ti wire substrates in an electrolyte containing ethylene glycol and NH4F. By a combination of field emission scanning electron microscope and X-ray photoelectron spectroscope studies, it is shown that perpendicularly orientated and well-aligned TiO2 nanotubes are grown in situ on the Ti wire substrate. The SPME fiber coupled with gas chromatograph (GC) is then used to extract polycyclic aromatic hydrocarbons (PAHs), anilines, phenols, and alkanes from standard and real water samples, and exhibits high selectivity for PAHs. After the optimization of adsorption factors (pH, ionic strength, time and temperature) and desorption factors (time and temperature) of the SPME fiber for PAHs, the limit of detection (LOD) of less than 0.1μgL−1 is achieved, and the calibration curves are all linear (R 2 ≥0.9898) in the range from 0.1 to 1000μgL−1. Beyond that, the SPME fiber has high strength, large surface area, good stability at high temperature and in acid and alkali solutions, and long service life, making it have strong application potentials in the selective extraction of PAHs from complex samples at trace levels. [Copyright &y& Elsevier]

Abstract: Anatase TiO2 nanotubes (NTs) with the diameter of about 12nm and the length of several hundreds nanometers were synthesized by hydrothermal method. The samples were characterized by X-ray diffraction (XRD), transmitting electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmet–Teller (BET) measurements. The NTs are used to make composites photoanode with pristine TiO2 nanoparticles in dye-sensitized solar cells (DSSCs). It was found that the NT/nanoparticle ratio had a pronounced impact on the performance of solar cells. The electrode composite has better photoelectric properties than the full nanoparticle and NTs solar cells. The optimum content NTs, was found to be 5%, at which content the incident photon to current efficiency was about 63.1%, an 13.8% increment compared to that using full P25 under the same condition. [Copyright &y& Elsevier]

Abstract: Anatase TiO2 nanotubes and titanate nanotubes have been successfully synthesized via hydrothermal synthesis followed by post-treatment from titanium powder. The morphology and crystalline structure of the nanotubes are characterized in detail with transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) respectively. The nanotubes have an average outer diameter of around 9–10 nm and the inner diameter around 3–4 nm with several hundred nanometers in length. A mechanism for the anatase TiO2 nanotubes transformation has also been proposed. Nanotubes are formed during the solvent thermal process, and the compositions are changed by subsequent ionic exchange and dehydration under high temperature. These tubular materials can be very useful in the fields of photocatalysts, photoelectronics and energy-storage technologies. [Copyright &y& Elsevier]

Tunable water adhesion was realized on a TiO2nanotube film with patterned wettability formed viaselective illumination through a mask. Meanwhile, the adhesion can be switched between sliding superhydrophobicity and sticky superhydrophobicity by masked illumination and heat annealing. [ABSTRACT FROM AUTHOR]

Abstract: Micro-and nanoscale spherical anatase TiO2 films have been successfully prepared via evaporizing–deposition route. The morphology and the crystalline structure of the samples were characterized in more detail with field emission scanning electron microscopy (FE–SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The TiO2 films with micro-and nanoscale surface structures can be constructed by simply adjusting the evaporation condition of TiCl4 in the air after being annealed. These surfaces can be turned from super-hydrophilic to super-hydrophobic after modification with a thin layer of hydrophobic silicone, mainly depending on the surface morphology. [Copyright &y& Elsevier]

Molybdenum-doped TiO 2 nanotube arrays (Mo-doped TiO 2 NTs) photoelectrodes with anatase/rutile mixed phase are successfully fabricated via two-step anodization of titanium followed by a hydrothermal doping treatment process. The Mo-doped TiO 2 NT material shows higher photocurrent density and enhanced incident photon to current conversion efficiency (IPCE) compared with the pristine TiO 2 NTs for photoelectrochemical (PEC) water-splitting. The improvement of PEC response results from not only the increasing of oxygen vacancies and reducing of the recombination of photoexcited charges by Mo-doping, but also the new formed heterojunctions of anatase/rutile mixed-phase by hydrothermal treatment. Moreover, the Mo-doped TiO 2 NTs show high stability and obvious visible absorption with considerable photocurrent density under visible light (λ > 420 nm). [ABSTRACT FROM AUTHOR]

Graphical abstract The controllable phase heterojunction structure is afforded with augmented light absorption, high separation of photogenerated electron and hole pairs and unique band structure derived from the synergistic effect of the disordered layer, oxygen vacancy, branched and ordered structure, and phase heterojunction. Particularly, a high photocurrent density of 3.88 mA cm−2 is achieved by this photoelectrode. Highlights • The controllable fabrication of phase heterostructures is implemented by ALD. • The unique band structures suppress the recombination of photogenerated carriers. • The synergistic effect enhances the photocatalytic activity for water splitting. • The hydrogenated photoanode shows high photocurrent density of 3.88 mA cm−2. Abstract In this study, hydrogenated TiO 2 anatase/rutile phase heterojunction is fabricated and used for photoelectrochemical water splitting to generate clean H 2 energy under solar light. This TiO 2 phase heterojunction photocatalyst material with core-shell structures is accurately prepared by a hydrothermal method to grow the core of rutile TiO 2 nanorod arrays and an ALD technology to form the shell of the anatase TiO 2 layer with a controllable thickness, followed with a hydrogenated treatment to introduce some disordered structures and oxygen vacancies to the TiO 2 phase heterojunction. This new structured TiO 2 photocatalyst material yields a high photocurrent density of 3.88 mA cm−2 at 1.23 V vs.RHE under simulated solar light (100 mW cm−2) with a maximum IPCE of 59.7% at the wavelength of 380 nm. These values are almost 3.8 and 7.4 times higher than that of the bare rutile TiO 2 , respectively. The enhanced photoelectrochemical performances are mainly attributed to the synergistic effect of the core-shell phase heterojunction, highly ordered structure and post-hydrogenated treatment to accelarate the separation and transmission of the photogenerated electrons and holes. This hydrogenated TiO 2 core-shell phase heterojunction indicates promising potential applications in the fields of photoelectrocatalysis and photovoltaic devices under solar light. [ABSTRACT FROM AUTHOR]

In this study, titanium dioxide nanotube arrays (TiO 2 -NTs) were prepared on titanium plates through a two-step anodization method and then the SnO 2 nanoparticles were deposited onto TiO 2 -NTs by electrodeposition method to produce SnO 2 -TiO 2 -NTs. The electrodeposition time has a great influence on the photoeletrochemical (PEC) performance of SnO 2 -TiO 2 -NTs composite photoelectrode. The photocurrent density of SnO 2 -TiO 2 -NTs electrode increased up to 4 times as compared to pristine TiO 2 -NTs photoelectrode. Furthermore, open circuit potential and tafel curves were measured to evaluate the photocathodic protection properties of SnO 2 -TiO 2 -NTs. The corrosion potential dropped to -730 mV and the corrosion current density reached to 259.8 μA/cm −2 . The results indicate that SnO 2 deposition into the TiO 2 -NTs photo-electrode is a simple and effective way to protect stainless steel (304SS) from corrosion. [ABSTRACT FROM AUTHOR]

A new photoanode polypyrrole nanowire/TiO 2 nanotube (PPy NW/TiO 2 NT) nanocomposite material with a coaxial heterojunction structure is constructed by electrodeposting p-type polypyrrole nanowire into n-type TiO 2 nanotubes. Photo-induced open circuit potential, photocurrent density, electrochemical impedance spectroscopy, and Tafel curves are measured under visible light to evaluate the photocathodic protection effect and anticorrosion properties of the nanocomposite. The results indicate that the synergistic effect between the photogenerated cathodic protection and the favorable corrosion resistance of the nanocomposite makes PPy NW/TiO 2 NTs nanocomposite a promising material for protecting Ti substrate and the coupled 304 stainless steel from corrosion. [ABSTRACT FROM AUTHOR]

[Display omitted] • SiP QDs was firstly used as a hole-migration cocatalyst for PEC water splitting. • SiP QDs/TiO 2 NRs/Al 2 O 3 showed enhanced PEC activities and stability. • The photocurrent density of composites is 3.29 times that of pure TiO 2 NRs. • Ultra-thin Al 2 O 3 was used as a passivation layer to prevent photo-corrosion. Silicon phosphide (SiP) is a new type of IV–V two-dimensional material with high thermal stability and adjustable bandgap, and it has broad prospects in optics, electricity, and photocatalysis. However, the practical application of SiP for photoelectrochemical (PEC) water splitting was rarely studied. Herein, for the first time, SiP quantum dots (QDs) were introduced as a hole-migration cocatalyst coupled with TiO 2 nanorods (NRs) via a hydrothermal and continuous dip coating method, and then SiP QDs/TiO 2 NRs/Al 2 O 3 was obtained by deposition of Al 2 O 3 layer through atomic layer deposition technology. The photocurrent density of SiP QDs/TiO 2 NRs/ Al 2 O 3 reached 2.14 mA cm−2 at 1.23 V versus RHE, and the IPCE value reached 65.04% at the wavelength of 375 nm under simulated solar light (100 mW cm−2); these values are nearly 3.29 and 4.88 times that of pure TiO 2 NRs, respectively. The enhanced PEC properties may be attributed to the enhanced light harvesting capability and the effective transport of photogenerated holes through the synergistic effects between SiP QDs and Al 2 O 3 passivation layer, which indicates the great potential in the hydrogen generation of solar energy. [ABSTRACT FROM AUTHOR]

In this study, a new photoelectrochemical material is fabricated by loading two-dimensional leaf-like Ti 3 C 2 MXene nanosheets into the TiO 2 nanorod array to form Ti 3 C 2 nanosheets/TiO 2 nanorod (Ti 3 C 2 /TiO 2 NR) composite photoanode materials. The unique two-dimensional/one-dimensional (2D/1D) composite photocatalytic materials enhance the photoelectrochemical water splitting performance under simulated solar light (100 mW cm−2) and yield a high photocurrent density of 1.41 mA cm−2 at 1.23 V vs. reversible hydrogen electrode (V vs. RHE) and photoconversion efficiency of 0.46% at 0.78 V vs. RHE , which are almost 3.13 and 5.82 times higher, respectively, than those of the pure rutile TiO 2 NRs. The enhanced photoelectrochemical performances are attributed to the photogenerated electrons produced by TiO 2 NR which could be quickly transported by Ti 3 C 2 nanosheets due to their good electrical conductivity and increased specific surface area, which improve the separation efficiency of electrons and holes. These Ti 3 C 2 /TiO 2 NR, as new photocatalytic materials, have promising potential applications in the fields of photoelectrochemical water splitting, solar cells, and other photocatalytic devices. • Leaf-like Ti 3 C 2 MXene nanosheets/TiO 2 nanorod photoanode is fabricated. • The Ti 3 C 2 /TiO 2 NRs shows improved PEC performance under simulated solar light. • The photocurrent density of Ti 3 C 2 /TiO 2 NRs is 3.13 times than that of TiO 2 NRs. • The Ti 3 C 2 /TiO 2 NRs shows a good long-term stability under simulated solar light. • The enhanced PEC performances are due to good electrical conductivity of Ti 3 C 2. [ABSTRACT FROM AUTHOR]

Al 2 O 3 anchored carbon quantum dots/TiO 2 nanorods (Al/C/TNRs) achieved high and stable photoelectrochemical performances under solar light, and could provide efficient photocathodic protection for Q235 CS in marine environment. • CQDs modified TiO 2 nanorods (CQDs/TiO 2) were fabricated for solar-driven photocathodic protection property of Q235 carbon steel. • Alumina ultrathin layer deposited by ALD technology is used for enhancing the photoelectrochemical stability of CQDs/TiO 2. • The composite displayed improved photoelectrochemical performances under solar light. • The composite has charge storage ability to maintain photocathodic protection for seven hours in dark. A new photoanode of Al 2 O 3 anchored carbon quantum dots/TiO 2 nanorods (Al/C/TNRs) was constructed for efficient photocathodic protection of Q235 carbon steel (CS) by hydrothermal treatment and ALD process. The Al/C/TNRs photoanode achieved a photocurrent density of 2.28 mA/cm2 under simulated sunlight (AM 1.5 G), and could maintain for 7 days nearly without decay. Potential of Q235 CS was negatively shifted by 620 mV after coupling with Al/C/TNRs in 3.5 wt% NaCl solution, and could maintain more than 7 h. The high and stable photoelectrochemical performances of Al/C/TNRs indicate potential photocathodic protection for Q235 CS in marine environment. [ABSTRACT FROM AUTHOR]