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W-doped/undoped TiO2 nanotube array (TNAs) photoelectrodes with different nanostructures were successfully fabricated using the anodization method. Their morphology and characteristics were studied using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and ultra violet/visible light diffuse reflectance spectra (UV/vis/DRS). Their electronic structure and optical properties were studied by means of first-principle. Photocatalytic (PC) performance of W-TNAs photoelectrodes with different crystal structures was evaluated using the decomposition rates of Rhodamine B (Rh.B) under xenon light illumination. The results demonstrated that W substituting Ti broadened the width of conduction band (CB) and valence band (VB) of anatase and rutile TiO2, reduced the band gap of rutile TiO2 and even caused its red-shift. W incorporated into TNAs photoelectrodes extended light absorption threshold and enhanced its utilization of solar light and PC activity, particularly, the PC performance of W-TNAs photoelectrodes with mixed crystal and rutile crystal structure. [ABSTRACT FROM AUTHOR]

Abstract In this research Ag2Mn8O16 nanocrystals/TiO2 nanotubes, photoelectrodes were successfully prepared through anodization and annihilation steps, followed by electrodeposition of MnO2 and Ag in a three electrodes cell. The obtained photoelectrodes were dried, then annealed for crystallization, the morphology and structure of the fabricated electrodes were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The light absorption and harvesting properties were investigated through UV–visible diffuse reflectance spectrum (DRS), photocatalytic performances were evaluated by degradation of 50 mL of Rhodamine B (5 mg L−1) under Xenon light irradiation for 2 h. Results illustrated that the fabricated photoelectrodes show remarkable photo-degradation properties of organic pollutants in aqueous mediums. [ABSTRACT FROM AUTHOR]

To improve the visible light photocatalytic (PC) activity of TiO2 photocatalyst, the well-aligned TiO2 nano-tubes (TiO2 NTs) were in-situ grown by anodization of Ti foils, and the graphene film was anodic electrodeposited onto the aforementioned TiO2 NTs to constructed graphene film decorated TiO, NTs (GF/TiOj NTs) photoelectrode. Apparent morphology, surface composition and light absorption ability of the resulting photoelectrodes were characterized by scanning electron microscopy ( SEM ), X-ray photoelectron spectroscopy (XPS) and UV-visible light diffuse reflection spectroscopy (UV-vis DRS). It was found that the graphene were successfully decorated onto the surface of TiO2 NTs electrode, and existed as the transparent film. In addition, the light absorption of GF/TiO2 NTs photoelectrode was greatly red-shifted to visible light region. Furthermore, the methyl blue (MB) was served as the probing molecules, and the effects of deposition voltage and deposition time on the PC performances were mainly investigated. It was found that when the deposition voltage and applied time were +0. 8 V and 10 min, respectively, the optimal photodecomposition of MB could be obtained. Under the simulated sunlight irradiation within 120 min, the 65. 9% degradation rate of MB could be achieved, which was 1. 35 time larger than that of pristine TiO2 NTs photoelectrode. [ABSTRACT FROM AUTHOR]

Highlights: [•] The influences of calcination temperature on TiO2 nanobelts were analyzed. [•] The optimal properties were obtained by calcination at 550°C. [•] This photocatalyst showed high efficiency in photocatalytic removal of amikacin. [ABSTRACT FROM AUTHOR]

To improve the visible light photocatalytic activity of TiO2, in this study, TiO2 nano-tubes arrays (TNTAs) were in-situ grown by anodization of Ti foils, and noble Pd nano-crystallites were electrochemical deposited onto the as-prepared TNTAs photoelectrode. The morphology, surface state and light absorption ability of the resulting electrodes were characterized by scanning electron microscopy (SEM), X -ray photoelectron spectroscopy (XPS) and UV-visible light diffuse reflection spectroscopy (UV-vis DRS), respectively. It was found that Pd nano-crystallites were successfully decorated onto the surface of TNTAs electrode, and existed as the form of Pd0. In addition, the light absorption of Pd/TNTAs photoelectrode was greatly red-shifted to visible region. Furthermore, methyl blue (MB) was served as the probe molecules, and the effects of deposition voltage and time on the photocatalytic (PC) performance were mainly investigated. It was found that when the deposition voltage and time were -0. 8 V and 10 rain, respectively, the optimal photodegradation of MB could be obtained, which fitted well with the pseudo-first-order kinetics formula. Under the simulated sunlight irradiation within 120 min, the 71.4% degradation rate of MB could be achieved, which was 1.5 times larger than that of bare TNTAs photoelectrode. [ABSTRACT FROM AUTHOR]

Highlights: [•] N-S-TiO2/TiO2 nanotube electrodes were prepared combined anodization and ultrasonic. [•] The photoelectrocatalytic properties of photoanodes were investigated in detail. [•] The enhanced visible light photocatalytic mechanism was proposed. [ABSTRACT FROM AUTHOR]

Abstract: Two different TiO2 nano-tubes arrays (TNTAs) have been successfully fabricated through constant potential anodic oxidization method, followed with post-annealing treatment. Morphologies and crystal structures of the as-fabricated TNTAs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that both TNTAs were comprised of anatase and rutile phase, while TNTAs-NH4F exhibited highly ordered nano-tubular structure. In addition, their photoelectrochemical (PECH) properties were investigated through open circuit potential (OCP) and photocurrent response. As a result, TNTAs-NH4F performed higher OCP (0.16mAcm−2), photovoltage (0.1897Vcm−2) and photo-convention efficiency (0.18%) than that of TNTAs-NaF which could result in the more effective separation and transfer of photoinduced electrons and holes. Furthermore, the analysis of photocatalytic (PC) performance and output of hydroxyl radicals ( OH) demonstrated that TNTAs-NH4F photoanode possessed higher PC activity than that of TNTAs-NaF for photodegradation of methyl blue (MB). The higher PECH and PC performance could be ascribed to the highly ordered nano-tubular structure and higher separation and transfer efficiency of photoinduced charge carriers. [Copyright &y& Elsevier]

Highlights: [•] Pd/TNTs photoelectrodes have been prepared through electrochemical deposition method. [•] The role of Pd on the enhancement of PC and PEC performance has been investigated. [•] Contribution of series of active species on the degradation of diclofenac has been investigated. [•] The enhanced PC mechanism of Pd/TNTs photoelectrode was proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] We prepared successfully immobilized TiO2 nanobelts by electrochemical anodization. [•] The morphology of TiO2 nanobelts is controlled by the composition of electrolyte, applied voltage and anodization time. [•] The formation of TiO2 nanobelts is a combined result of field-assisted etching and chemical dissolution. [•] The TiO2 nanobelts exhibit higher photoelectrochemical and photocatalytic activities than nanotubes. [ABSTRACT FROM AUTHOR]

Abstract: TiO2/Ti Nanotube array (TNTa) photoelectrodes were prepared by galvanostatic and potentiostatic anodization technique, and annealed at different temperature. The morphology and structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectra. Optical properties and photoelectrochemical (PECH) properties were investigated by surface photovoltage (SPV), ultra UV–vis diffuse reflectance spectra (UV/vis/DRS), open-circuit potential (OCP) and transient photocurrent. Photodecomposition performances were evaluated by the yield of •OH radicals and photocatalytic (PC) degradation rate of 4-nonylphenol (4-NP) under xenon light. The results showed that with the increase of post-treatment temperature, PECH and PC properties increased gradually and then decreased. The photocurrent densities, yield of ⁎OH radicals and photodecomposition rates of 4-NP were following the trend of TNT-823>TNT-873>TNT-773>TNT-673>TNT-973>TNT-298. When the annealing temperature was 823K, the photoelectrodes were composed of mixed crystal structure and ordered nanotube array, which exhibited superior PECH properties. When the annealed temperature arrived to 973K, the nanotube collapsed and the PECH and PC properties of TNTa photoelectrodes decreased. For TNT-823 photoelectrodes, after the assistant potential was applied, the degradation rate of 4-NP increased significantly from 77% to 97% after 120min illumination. [Copyright &y& Elsevier]

Abstract: TiO2 photocatalysts with high photocatalytic activity are potentially applied to degrade pollutants, split water and transform solar energy. Herein, TiO2 nanobelts (TiO2 NB) arrays originating from nanotubes arrays were successfully prepared via simple anodization. The surface morphology, structure, elemental composition, photoluminescence spectra (PL), photoelectrochemical (PEC) properties and photocatalytic activity of the resulting samples were investigated. The results show that as-prepared TiO2 NB arrays exhibited significant enhancement in separation efficiency of photogenerated electrons (e−) and holes (h+) pairs and then in photocatalytic activity under simulative solar irradiation compared with TiO2 nanotubes (TiO2 NT) arrays, which could be attributed to the following aspects: (i) specific belt-like morphology leads to higher accessibility of TiO2 NB arrays for reactants and more active sites on the surface of TiO2 NB; (ii) single-crystalline anatase phase structure gives rise to faster electron mobility and less electron-trapping sites in the bulk; and (iii) exposed crystal face (101) yields an enhanced reactivity with molecular O2, facilitating the trapping of photogenerated electrons and generation of superoxide radical. Otherwise, this TiO2 NB arrays overcome the deficiency of filtering separation from water and exhibit excellent photocatalytic stability, thus it is promising to be applied in pollutants elimination and photocatalytic decomposition of water. [Copyright &y& Elsevier]

Several kinds of N-doped/undoped TiO photoelectrodes with different nanostructures have been successfully prepared by anodization method and plasma-based ion implantation (PBII) technique. The morphology and structure of as-prepared photoelectrodes were studied by scanning electron microscopy, X-ray diffraction, and ultra violet/visible light diffuse reflectance spectra. Electronic structure and optical properties were calculated by means of first-principle. Photocatalytic (PC) and photoelectrocatalytic (PEC) performance were measured by the decomposition of terephthalic acid (TA) and Rhodamine B under xenon light illumination. Theoretical calculation results demonstrated that crystal phases have great influence on the electric and optical properties, and N-doped TiO photoelectrodes have isolated N impurity states nearby the top of the valence band. The optical properties and UV/Vis analysis confirmed that the absorption edge of N-TiO emerged red-shift and high photosensitivity. The discrepancy of PC and PEC performance of as-prepared TiO photoelectrodes were ascribed to band gap narrowing, N impurity states, self-semiconductor coupling effect, and long-range ordered orientation of photogenerated carries originated from applied electric field. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 photoelectrodes with various nanostructures have been successfully prepared by the anodization method. The morphology, microstructure and optical properties of as-prepared photoelectrodes were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), ultraviolet/visible light diffuse reflectance spectra (UV/vis/DRS), surface photovoltage spectroscopy (SPS) and photocurrent. The electronic structure and optical properties of La doped/undoped TiO2 photoelectrodes with different crystal structures were calculated by the density function theory. The photocatalytic and photoelectrocatalytic activities of as-prepared photoelectrodes were evaluated. The results showed that the anodization potentials played a crucial role in the surface morphology and microstructure. Both results of theoretical calculations and experimental tests demonstrated that La-doped photoelectrodes were more sensitive to light than undoped one. The difference of photoelectrodes performance was ascribed to the crystal configuration, impurity energy levels and long-range orientation moving of photogenerated carriers. [Copyright &y& Elsevier]

Abstract: Wormhole-shaped TiO2/Ti (WT) and nanotube-shaped TiO2/Ti (TNT) photoelectrodes were prepared by anodic oxidation method. The morphology and structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was found that both crystal types of WT and TNT photoelectrodes were composed of anatase and rutile TiO2 phases; however TNT photoelectrodes had highly ordered nanostructure. The photoelectrochemical (PECH) and photoelectrocatalytic (PEC) properties of WT and TNT photoelectrodes were investigated by photocurrent transient, open-circuit potential and degradation rate of alachlor under the artificial solar light illumination. All results showed that TNT photoelectrodes prepared in NaF–Na2SO4 solution have more excellent photoelectron properties than WT photoelectrodes prepared in H2SO4 solution. The photocatalytic (PC) and PEC experiments of alachlor showed that PC and PEC activities of TNT photoelectrodes were superior to WT photoelectrodes. At applied bias potentials the degradation rate of alachlor at TNT photoelectrodes increased significantly to 94.5%. The higher PC and PEC performance of TNT photoelectrodes were ascribed to the long-range ordered structure and short-orientation diffusion distance of photogenerated carries. [Copyright &y& Elsevier]

Abstract: Nitrogen doped TiO2/Ti photoelectrodes were prepared by a sequence of anodization and plasma based ion implantation (PBII). The properties of this photoelectrode were characterized by scanning electronic microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS), Ultra violet/visible light diffuse reflectance spectra (UV/vis/DRS), surface photovoltage (SPV), etc. Photoelectrocatalytic (PEC) performance of N-doped TiO2/Ti photoelectrode was tested under visible light irradiation. Their photocatalytic activity was evaluated by degradation of Rhodamine B (Rh.B). The results of XPS showed that nitrogen element was in form of three species, i.e. β-N, molecular γ-N and O–Ti–N, which existed in the lattices of TiO2 and gaps between molecules. The results of UV/vis/DRS spectra and SPV revealed that proper doping of nitrogen could expand the response of photoelectrodes towards visible light and diminish the recombination of photo-generated holes and electrons, respectively. The photoelectrocatalytic activity of N-doped TiO2/Ti photoelectrodes was superior to those of undoped one under visible light region irradiation. [Copyright &y& Elsevier]

[Display omitted] • Exfoliation coupled Cu(II) anchoring strategy was developed to modulate the configuration of vermiculite. • The sample exhibited adsorption/photocatalytic synergy ability toward TC removal. • The loaded Cu(II) provided complexation sites for increasing TC enrichment. • The generated heterogeneous Cu(III) was responsible for further TC oxidation. Integrated adsorption and photocatalysis is a worth frontier strategy for recalcitrant organics elimination, yet the current challenge is developing materials featured with dual functions of adsorption/photocatalytic ability. In this scenario, a novel attractive exfoliated vermiculite coupling with Cu(II) composite (eVT@Cu) was tactfully engineered. Specifically, exfoliated structure containing vast negative charge was conductive for Cu(II) loading. The anchored Cu(II) played triple roles in this system, that is, regulating electron configuration of photocatalyst with narrow bandgap, as well as providing complexation sites for tetracycline (TC) enrichment. With the help of inherent Fe(III), Cu(II) was readily to form heterogeneous high-valence Cu(III) driven by photonic energy. Benefited by these effects, eVT@Cu exhibited extremely augment on TC removal compared to pristine VT and eVT, with ca. 80% removal efficiency through the synergy of adsorption and photocatalysis. Overall, this study not only provides an excellent environmental candidate for TC removal but also opens a brand-new perspective for the generation of heterogeneous high-valence Cu(III) over eVT@Cu under visible light. [ABSTRACT FROM AUTHOR]

Ag/GO/g-C 3 N 4 composites were successfully synthesized by a sonochemical method. The structure and properties of the composites at various Ag loadings were characterized, and the Ag nanoparticles were confirmed by XRD, TEM and XPS measurements. UV–Vis diffuse reflectance spectra showed the presence of surface plasmon peak for Ag at 550 nm. The Ag/GO/g-C 3 N 4 composites demonstrated excellent activity in photocatalytic degradation of Rh B under visible light irradiation, and 5% of Ag nanoparticle was found to be the most suitable loading. The enhanced photocatalytic activity was ascribed to the role of GO nanosheets and Ag nanoparticles. The GO nanosheets acted as electrons transporter and acceptor in the composite and inhibited the charge recombination. The Ag nanoparticles acted as an electron traps to facilitate the separation of photogenerated electron-hole pairs and promoted interfacial electrons transfer. The OH ads and h + were the major radicals to be involved in the photocatalytic process. [ABSTRACT FROM AUTHOR]

In this study, Ag-Ag 2 O/reduced TiO 2 (denoted as Ag-Ag 2 O/r-TiO 2 ) nano-photocatalyst had been fabricated through one-step solution reduction strategy in the presence of potassium borohydride. Afterwards, physicochemical properties of the resulting samples were investigated by scanning electron microscope (SEM), N 2 adsorption/desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV-vis DRS), electron spin resonance (ESR) and time-resolved surface photovoltage (TR-SPV) techniques. Results indicated that potassium borohydride treatment could simutaneously induce the generation of Ti 3+ self-doping energy level between the forbidden band of TiO 2 and metallic Ag species existed in the forms of Ag 0 and Ag 2 O nanocrystalline, thereby resulting in the greatly enhanced visible light absorbance and photoinduced charge separation efficiency. In addition, the visible light driven (VLD) photocatalytic (PC) performance was evaluated through the degradation of diclofenac and generation of ·OH radicals. As-expected, Ag-Ag 2 O/r-TiO 2 sample exhibited higher VLD PC performance and larger generation amount of ·OH radicals. Furthermore, the enhanced VLD PC mechanism was proposed and confirmed, which was mainly attributed to the synergistic effect originated from the localized SPR of Ag 0 nanocrystalline and Ti 3+ self-doping which responsible for the intense visible light absorbance, high photoinduced charge separation efficiency and VLD PC performance. [ABSTRACT FROM AUTHOR]

In this study, we reported a facile strategy to fabricate N, Ti 3+ codoped TiO 2 nanotubes (N-Ti 3+ /TiO 2 NTs) photoelectrode through one-step solution reduction process. The hydrazine hydrate treatment induced the simultaneous formation of Ti 3+ species and N-doping in the lattice of TiO 2 NTs. In addition, the N-Ti 3+ /TiO 2 NTs photoelectrode exhibited intense visible light absorption ranging from 400 to 800 nm, high transient photoinduced current of 0.213 mA cm −2 , charge carriers concentration of 0.92 × 10 19 cm −3 , generation of hydroxyl radicals and PEC efficiency of 100% for the degradation of diclofenac solution within 4 h visible light irradiation. The enhanced-visible-light PEC performance was mainly attributed to the enhancement of visible light absorbance, narrow band gap energy and high separation efficiency of photoinduced charge carriers. This study provides a facile strategy to construct intense visible light active catalyst, which could be applied in the fields of wastewater/air purification, solar energy conversion and water splitting. [ABSTRACT FROM AUTHOR]

In the present work, narrow band gap Ag 2 S nano-crystallites decorated TiO 2 nanotubes arrays (Ag 2 S NCs/TiO 2 NTAs) photoelectrode was successfully constructed through anodization, followed by successive ionic layer adsorption and reaction (SILAR) strategy. Subsequently, morphologies and chemical structures were investigated through scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). In addition, the optical and photoelectrochemical (PECH) properties were recorded through Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), transient photocurrent density and Mott-Schottky measurements. Furthermore, the photocatalytic (PC) performance was evaluated through the yield of hydroxyl (·OH) radicals and degradation of methyl blue under visible light illumination. All results indicated that Ag 2 S NCs/TiO 2 NTAs photoelectrode exhibited intense visible light absorbance, high transient photocurrent of 0.098 mA · cm −2 and charge carrier concentration of 1.58 × 10 19 · cm −3 , as well as effective PC performance of 83.6% for the degradation of methyl blue. Besides, · OH radicals was the dominated responsible active species during the PC process. The enhanced visible light PC performance was mainly attributed to the intense visible light absorbance and high charge carrier separation efficiency. [ABSTRACT FROM AUTHOR]

In order to improve the separation efficiency of photogenerated charge carriers and photocatalytic (PC) performance of TiO 2 nanotubes (TiO 2 NTs) photoelectrode, Pd nanoparticles and reduced graphene oxide co-modified TiO 2 NTs (Pd-RGO/TiO 2 NTs) photoelectrode was fabricated through two-step electro-deposition in this study. Subsequently, physicochemical properties of the resulting samples were investigated through SEM, XRD, XPS and Raman techniques. Additionally, the generation of OH was detected by fluorescence spectra using terephthalic acid as the probing molecule. Furthermore, the photoelectrochemical properties of Pd-RGO/TiO 2 NTs photoelectrode were studied through UV–vis DRS, photocurrent density and electrochemical impedance spectroscopy. As a result, Pd-RGO/TiO 2 NTs photoelectrode exhibited a significantly enhanced photocurrent density of 0.111 mA cm −2 and charge carrier concentration of 1.43 × 10 19 cm −3 , as well as efficient PC performance of 58.4% for the degradation of diclofenac aqueous solution. Moreover, the enhanced-PC mechanism was proposed. The efficient visible PC performance of Pd-RGO/TiO 2 NTs photoelectrode could mainly be attributed to the co-modification of Pd and RGO species, which could not only improve the light harvesting property, but also the effective separation of photogenerated charge carriers. Furthermore, the enhanced PC mechanism for degradation of diclofenac was proposed and confirmed. This study provides an effective strategy to fabricate TiO 2 NTs-based photoelectrode which could be applied in the fields of organic pollutants elimination and wastewater treatment. [ABSTRACT FROM AUTHOR]

• A flexible filter-membrane-like peroxydisulfate-coupled photocatalytic system is developed. • The system can produce energetic active species (·OH, SO 4 ·−, h +, O 2 ·− and 1O 2). • The system exhibits a superior performance towards tetracycline degradation. • The pretreatment guarantees microbial diversity and richness. • The pretreatment reduces the emergence and dissemination risk of antibiotic resistance genes. The direct biological treatment of antibiotics containing wastewater brings about a potential risk of antibiotic resistance genes (ARGs) spread. Although advanced oxidation technologies based on photocatalysis generally appear effective at degrading antibiotics in wastewater, the fate of ARGs in succeeding biological treatment system is still unknown. Herein, a filter-membrane-like carbon cloth-immobilized Fe 2 O 3 /g-C 3 N 4 photocatalyst is fabricated through immersion-calcination method. Peroxydisulfate-coupled photocatalysis system is developed to degrade tetracycline (TC, an emerging refractory antibiotic pollutant). The system can produce energetic active species (·OH, SO 4 ·−, h +, O 2 ·− and 1O 2), exhibiting a superior performance towards TC degradation in static and continuous flow processes under visible-light irradiation. The pretreatment can eliminate the antibacterial activity of antibiotics wastewater, and the chemical oxygen demand removal is greatly enhanced in subsequent anaerobic or aerobic process. The microbial diversity and richness in activated sludge for pretreated water sample are significantly higher than those for the water sample without pretreatment. Meanwhile, the pretreatment can decrease the relative abundance of potential hosts of ARGs and reduce the emergence as well as dissemination risk of ARGs. This study uncovers the effect of pretreatment of antibiotics containing wastewater using advanced oxidation technologies on the treatment efficacy and antibiotic resistome fate in biological treatment system. [Display omitted] [ABSTRACT FROM AUTHOR]