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Hematite (α-Fe 2 O 3 ) is a promising photoanode material for light-driven water splitting to make solar fuels. Herein, boron incorporated hematite photoanodes are successfully fabricated by a simple impregnation treatment in borate solution before annealing the iron oxyhydroxide (FeOOH) precursor. X-ray diffraction, Raman and X-ray photoelectron spectroscopies revealed regional enrichment of boron and oxygen vacancy near the outmost surface of the photoanode, forming a unique heterostructure. The boron modified photoanodes exhibited significantly improved photoelectrochemical (PEC) water oxidation efficiency, with up to 37 times enhancement in photocurrent density, approaching 1.12 mA cm −2 at 1.23 V RHE under AM 1.5 G illumination. Electrochemical impedance spectroscopy demonstrated a more favorable hole transfer process in the modified photoanode, which can be ascribed to the surface heterostructure induced build-in electric field, as well as the increase in carrier density introduced by oxygen vacancy. [ABSTRACT FROM AUTHOR]

Abstract: The supported nano-TiO2 electrode was prepared by sol–gel and hydrothermal method, and the photoelectrocatalytic degradation of 4-chlorophenol (4-CP) under UV irradiation has been investigated to reveal the roles of hydroxyl radicals and dissolved oxygen species for TiO2-assisted photocatalytic reactions. The degradation kinetics, the formation and decay of intermediates, the isotopic tracer experiments with H2O18, the removal yield of total organic carbon and the formation of active radical species in the presence of oxygen or not were examined by HPLC, GC–MS, TOC and spin-trap ESR spectrometry. It was found that most of ls in the primary hydroxylated intermediates derived from the oxidation of adsorbed H2O or HO− by photo-holes in the electrochemically assisted TiO2 photocatalytic system. It also indicates that the enhancement in the separation efficiency of photogenerated charges by applying a positive bias (+0.5V vs SCE) has little role in the following decomposition and mineralization of these hydroxylated intermediates in the absence of oxygen. According to above experimental results, the pathway of 4-CP photocatalytic degradation was deduced initially. Due to the combined effect of ls and dissolved oxygen species, the hydroxylated 4-chlorphenol, via cis, cis-3-chloromuconic acid, was decomposed into low molecular weight acid and CO2. [Copyright &y& Elsevier]

Nanosized coupled ZnO/SnO2 photocatalysts with different Sn contents were prepared using the coprecipitation method, and characterized by X-ray diffraction, specific surface area and UV-Vis diffuse reflectance spectroscopy. The phases, mean grain sizes and band gap energy of the coupled ZnO/SnO2 photocatalysts varied with the Sn contents and the calcination temperatures. The photocatalytic activities of the coupled ZnO/SnO2 photocatalysts, evaluated using the photodegradation of methyl orange as a probe reaction, were also found to be related to the calcination temperatures and the Sn contents. The photocatalytic activities of the coupled ZnO/SnO2 photocatalysts decreased with the increasing calcination temperatures. The maximum photocatalytic activity of the coupled ZnO/SnO2 photocatalyst, which is about 1.3 times the photocatalytic activity of ZnO and 21.3 times that of SnO2, was observed with a Sn content of 33.3 mol% under calcination at 500 °C for 10 h. The enhancement of the photocatalytic activity might arise from the hetero-junctions ZnO/SnO2 in the coupled oxides. The photo-stability of the ZnO/SnO2 photocatalyst was also studied. [Copyright &y& Elsevier]

Two dye-sensitized semiconductor titanium dioxide films containing copper(II) phthalocyaninechloride (CuPcCl14–15) and copper(II) phthalocyaninetetrasulfonic acid (CuPcTs) TiO2 films were prepared. Their bactericidal effects under visible light irradiation were measured. Experimental results indicate that these films inhibit the growth of Escherichia coli under visible light irradiation, and the bactericidal efficiency is related to the coverage of the TiO2 films. A possible mechanism was proposed. [Copyright &y& Elsevier]

Transparent mesoporous TiO2 (MTiO2) and TiO2 nanometer thin films were prepared on fused quartz via the modified reverse micellar and sol–gel methods. The MTiO2 and TiO2 films were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray diffraction (XRD), BET surface area and UV–Vis spectrophotometry. The photoinduced super-hydrophilicity and photocatalytic activity of the films were evaluated by the water contact angle measurement and photocatalytic oxidation of acetone in air, respectively. It was found that MTiO2 thin films at 500 °C showed higher photocatalytic activity and better light-induced hydrophilicity than the TiO2 thin films. This is attributed to the following reasons: (1) MTiO2 thin films are composed of smaller monodisperse spherical particles about 15 nm diameter, and possess more mesopores between spherical particles and higher surface areas and surface roughness, (2) the monodispersity of MTiO2 particles was beneficial to the transfer and separation of photo-generated electrons and holes inside of and on the surface of TiO2 particles, and reduced the recombination of photo-generated electrons and holes. At 900 °C, the MTiO2 and TiO2 films appeared to be in the rutile phase, but showed photoinduced hydrophilicity and no photocatalytic activity. This confirmed that the mechanism of photoinduced super-hydrophilicity of the films is different from that of photocatalytic oxidation. [Copyright &y& Elsevier]