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The dual Z-scheme heterojunction CuBi2O4/Bi2Sn2O7/Sn3O4(CBS) was successfully constructed through in situ growth methods, and its photocatalytic performance was evaluated via degradation of tetracycline hydrochloride under visible light. Out of all samples, CBS-2 exhibited the highest photocatalytic activity, with an apparent rate constant of 2.34, 20.16, and 44.17 times that of Bi2Sn2O7, CuBi2O4, and Sn3O4, respectively. Even after four cycles, the photocatalytic efficiency remained above 85%. The improvement can be attributed to the construction of the Z-scheme heterojunction, which effectively promotes the separation and migration of photogenerated carriers. The possible photocatalytic degradation mechanism of dual Z-scheme heterojunction CBS was deduced based on the theory of free radical capture and energy band. [ABSTRACT FROM AUTHOR]

Constructing heterostructures with efficient charge separation is a promising route to improve photocatalytic hydrogen production. In this paper, MoS x /CdS/KTaO 3 ternary heterojunction photocatalysts were successfully prepared by a two-step method (hydrothermal method and photo deposition method), which improved the photocatalytic hydrogen evolution activity. The results show that the rate of hydrogen evolution for the optimized photocatalyst is 2.697 mmol g−1·h−1under visible light, which is 17 times and 2.6 times of the original CdS (0.159 mmol g−1 h−1) and the optimal CdS/KTaO 3 (1.033 mmol g−1 h−1), respectively, and the ternary photocatalyst also shows good stability. The improvement on photocatalytic hydrogen evolution performance can be attributed to the formation of heterojunction between the prepared composite materials, which effectively promotes the separation and migration of photo-generated carriers. Amorphous MoS x acts as an electron trap to capture photogenerated electrons, providing active sites for proton reduction. This provides beneficial enlightenment for hydrogen production by efficiently utilizing sunlight to decompose water. • Successful preparation of a novel MoS x cocatalyst-modified CdS/KTO heterostructure without noble metals. • Composite catalysts exhibit excellent photocatalytic hydrogen evolution performance. • The hydrogen production rate of the composite is 17 times and 2.6 times that of pure CdS and CdS/KTO. • Amorphous MoS x acts as a trap to capture photogenerated electrons, providing active sites for proton reduction. [ABSTRACT FROM AUTHOR]

• Double Z heterojunction g-C 3 N 4 /Bi 2 O 2 CO 3 /MnWO 4 with strong internal electric field was successfully prepared. • Under visible light irradiation, the double Z-scheme heterojunction g-C 3 N 4 /Bi 2 O 2 CO 3 /MnWO 4 coupled with the activation of PMS efficiently degrades 90.07 % of Iohexol within 40 min. • The catalytic system shows good cycle stability. • By constructing a double Z-scheme heterojunction, the electron transfer within g g-C 3 N 4 /Bi 2 O 2 CO 3 /MnWO 4 can be effectively facilitated, accelerating the electron transfer and enhancing the migration rate of photogenerated carriers. • Activating PMS can generate more reactive free radicals, among which, 1O 2 and h + are the main reactive radical and · OH, · SO 4 - and · O 2 – provided most of the help for the elimination of Iohexol. This paper describes the preparation of a double Z heterojunction photocatalyst, g-C 3 N 4 /Bi 2 O 2 CO 3 /MnWO 4 (CBCM), with a potent internal electric field using the hydrothermal method. The degradation efficiency can be further improved by combining photocatalytic technology with activated persulfate (PMS) technology. The synthesis of CBCM-7 was validated through XRD and TEM analyses, while XPS provided evidence of electron transfer and the establishment of heterojunctions within its structure. Additionally, PL, PC, and EIS measurements underscored CBCM-7′s proficient rate of photogenerated charge separation and robust charge transfer properties. The experimental results showed that the photocatalytic degradation of the iodinated contrast agent was substantially enhanced by this catalyst coupled with PMS. The degradation rate of Iohexol was up to more than 90 % within 40 min. After the completion of the recycling experiment, the degradation efficiency of this system remained above 80 %. Mechanistic analyses, including EPR tests, indicate that the main active groups generated by the degradation of this dual Z-scheme heterostructured photocatalyst coupled with activated PMS were superoxide radicals and hydroxyl radicals. [ABSTRACT FROM AUTHOR]

• A novel BiOBr/BiOCOOH p-n heterojunction photocatalyst was prepared for the first time. • The composites exhibited significantly enhanced activity for Levofloxacin degradation. • The heterojunctions promote the photo-generated carriers transmission and separation. BiOBr/BiOCOOH p-n heterojunction photocatalysts were fabricated via a two-step solvothermal method. The photocatalytic performance of as-prepared heterojunctions was evaluated under visible light for the degradation of Levofloxacin. The composite samples exhibited significantly accelerative degradation rate compared to both pure catalysts (BiOBr and BiOCOOH). Besides, the apparent rate constant of the optimal sample for Levofloxacin degradation was 1.7 and 144.8 times higher than that of pure BiOBr and BiOCOOH. The improved activity can be attributed to the high charge separation efficiency. Furthermore, quenching experiment was also carried out. The results indicated that the photogenerated hole (h+) and superoxide radical (O 2 −) were the dominant reactive radicals responsible for the degradation of Levofloxacin. Cycling test also reveals that the sample owned good stability. In the end, a possible photocatalytic degradation mechanism was proposed. This work would provide a good example for the design and preparation of bismuth based p-n heterojunction composite photocatalysts with high visible-light-responsive performance for environment purification. [ABSTRACT FROM AUTHOR]

Novel CdS/La 2 Ti 2 O 7 /NiS 2 ternary composite photocatalysts without noble metal were successfully constructed by a simple hydrothermal method. Under visible light irradiation (λ > 400 nm), the optimal CdS/La 2 Ti 2 O 7 /NiS 2 composite produced H 2 at a rate of about 12.77 mmol g−1 h−1, which was 84 times as high as that of pure CdS. This performance enhancement can be attributed to the formation of multiple heterojunctions (including CdS/NiS 2 , CdS/La 2 Ti 2 O 7 and CdS/La 2 Ti 2 O 7 /NiS 2 interface structures) between the three components in the as-prepared CdS/La 2 Ti 2 O 7 /NiS 2 composites. The formed multiple heterojunctions help to separate electron-hole pairs more quickly and efficiently, thus greatly increasing the photocatalytic activity of the CdS/La 2 Ti 2 O 7 /NiS 2 composites. This is very important for the utlization of solar energy for water splitting. • CdS/La 2 Ti 2 O 7 /NiS 2 ternary composite photocatalysts were prepared for the first time. • The composites exhibited greatly enhanced photocatalytic hydrogen evolution rate. • Multiple heterojunctions between NiS 2 , La 2 Ti 2 O 7 and CdS contributed to the high activity. [ABSTRACT FROM AUTHOR]

Highlights • A novel Bi 2 MoO 6 /BiOCOOH heterojunction photocatalyst was prepared for the first time. • The composites exhibited significantly enhanced activity for Ofloxacin degradation. • The heterojunctions promote the photo-generated carriers transmission and separation. Abstract Bi 2 MoO 6 /BiOCOOH heterojunction photocatalysts were successfully fabricated via a facile solvothermal method. The as-fabricated composite photocatalysts displayed greatly accelerated degradation rate toward Levofloxacin under visible-light irradiation. Typically, the incorporation ratio of Bi 2 MoO 6 had apparent effect on the performance of the heterojunction photocatalysts. The apparent rate constant of optimal sample for Levofloxacin degradation was 11.3 and 241.3 times higher than that of pure Bi 2 MoO 6 and BiOCOOH, respectively. The main reason for the improved performance was ascribed to the formation of heterojunctions between the two components. Results of the quenching studies indicated that both photogenerated hole (h+) and superoxide radical (·O 2 −) were main reactive radicals responsible for the degradation of Levofloxacin. Herein, the Bi 2 MoO 6 /BiOCOOH heterojunction could be a favorable material for visible-light-utilized water purification. Graphical abstract Image, graphical abstract Bi 2 MoO 6 /BiOCOOH heterojunction photocatalysts were successfully fabricated via a facile solvothermal method for the first time. The as-obtained photocatalysts showed significantly enhanced activity for Ofloxacin degradation under visible light irradiation. The optimum apparent rate constant reached up to 11.3 and 241.3 times as that of pure Bi 2 MoO 6 and BiOCOOH, respectively. [ABSTRACT FROM AUTHOR]

In this work, we prepared a new wide band gap semiconductor, p -block metal oxyhydroxide InOOH, which exhibits efficient activity for perfluorooctanoic acid (PFOA) degradation under mild conditions and UV light irradiation. The apparent rate constant for PFOA degradation by InOOH is 27.6 times higher than that for P25 titania. Results show that ionized PFOA (C 7 F 15 COO − ) can be adsorbed much more efficiently on the surface of InOOH than P25. Then, the adsorbed C 7 F 15 COO − can be decomposed directly by photo-generated holes to form C 7 F 15 COO radicals. This process is the key step for the photocalytic degradation of PFOA. Major degradation intermediates, fluoride ions and perfluorinated carboxylic acids (PFCAs) with shorter chain lengths were detected during PFOA degradation. A possible pathway for photocatalytic degradation of PFOA is proposed based on the experimental results. Therefore, this studies indicates a potential new material and method for the efficient treatment of PFCA pollutants under mild conditions. [ABSTRACT FROM AUTHOR]

The construction of a Z-scheme heterojunction favors the improvement of the photocatalytic activity of photocatalysts. Herein, the LaVO 4 /Bi 3 O 4 Cl Z-scheme heterojunction was designed reasonably by the method of in situ growth. The obtained heterojunction was further used as a photocatalyst for the degradation of ofloxacin (OFX), an antibiotic, in wastewater. The degradation efficiency of OFX by the optimal sample (LBC-2) was 94.3 % and the values of k were about 114.7 and 2.4 times those of LaVO 4 and Bi 3 O 4 Cl, respectively. In addition, LBC-2 maintained high activity after 4 cycles. The significantly reduced recombination rate of carriers in LBC-2 was reflected by the results of the photoluminescence (PL), photocurrent (PC), and electrochemical impedance spectroscopy (EIS) studies. The degradation pathways of OFX were proposed accounting to the intermediates detected by liquid chromatography-mass spectroscopy (LC-MS). Toxicity estimations showed that the toxicity of some intermediates decreased. This work provides new insight into the development of Z-scheme photocatalysts for the removal of antibiotics as pollutants. • Novel Z-scheme LaVO 4 /Bi 3 O 4 Cl composite photocatalysts were synthesized. • LaVO 4 /Bi 3 O 4 Cl composites exhibited excellent activity for ofloxacin degradation. • The apparent rate constant for ofloxacin degradation was about 114.7 and 2.4 times as that of LaVO 4 and Bi 3 O 4 Cl. • Z-scheme heterojunction boosted the fast transfer of charge carriers. • The degradation pathway of ofloxacin was deduced. [ABSTRACT FROM AUTHOR]

• Novle Z-scheme Bi 4 O 5 I 2 /Bi 3 TaO 7 composite photocatalysts were synthesized. • The photocatalyst exhibited high performance for levofloxacin degradation. • The apparent rate constant for levofloxacin degradation was 4.1 and 14.1 times as that of Bi 4 O 5 I 2 and Bi 3 TaO 7. • The mechanism on the enhanced performance was discussed deeply. Constructing a Z-scheme heterojunction with excellent oxidation–reduction ability is an effective way to develop high-efficiency photocatalysts for environmental pollution control. Herein, the synthesis and characterization of a novel Z-scheme Bi 4 O 5 I 2 /Bi 3 TaO 7 heterojunction photocatalyst are reported, and the photocatalytic performance of samples is evaluated by the degradation of levofloxacin (LVFX) under visible light. The optimal composite photocatalyst (BIT-3) showed the highest photocatalytic activity, and its apparent rate constants were 4.09 and 14.13 times as that of Bi 4 O 5 I 2 and Bi 3 TaO 7 , respectively. The improvement of photocatalytic activity can be attributed to the formation of 2D/0D heterojunction (conformed by TEM) between Bi 4 O 5 I 2 and Bi 3 TaO 7 , which effectively promotes the separation and migration of photogenerated electron-hole pairs (conformed by PL and photocurrent), and retains photogenerated carriers with strong redox ability. According to the results of radical capture and energy band theory, the photocatalytic reaction mechanism of direct Z-scheme Bi 4 O 5 I 2 /Bi 3 TaO 7 was proposed. The intermediate products in the degradation process of LVFX were determined by liquid chromatography-mass spectrometry (LC-MS), and the possible degradation pathway was put forward. [ABSTRACT FROM AUTHOR]

The direct Z-scheme Bi 3 TaO 7 /Mn 0.5 Cd 0.5 S (MCS) composite photocatalyst was successfully constructed by an in-situ growth method. The performance for levofloxacin degradation by the composite catalysts under visible light irradiation was studied. The k value of BMCS-3 is the highest (0.05813 min−1), which is 3.1 times larger than that of BTO (0.01846 min−1) and 7.0 times larger than that of pure MCS (0.00825 min−1). The photocurrent (PC), photoluminescence (PL) spectroscopy and electrochemical impedance spectroscopy (EIS) suggested that the migration rate of photogenerated electrons and holes were greatly improved after the combination of Bi 3 TaO 7 and Mn 0.5 Cd 0.5 S. On one hand, the separation efficiency of photogenerated electron-hole pairs of the composite material was improved due to the formation of Z-scheme heterojunction. On the other hand, the redox ability of photogenerated electron-hole pairs was maintained, which helped the composite material to exhibit enhanced photocatalytic performance. Meanwhile, the possible pathways of levofloxacin degradation and the toxicity of the produced intermediates were investigated. [Display omitted] • Novel Z-scheme Bi 3 TaO 7 /Mn 0.5 Cd 0.5 S composite photocatalysts were synthesized. • The photocatalyst exhibited high performance for the degradation of levofloxacin. • The rate constant improved by a factor of 3.1 and 7.0 compared to Bi 3 TaO 7 and Mn 0.5 Cd 0.5 S. • The mechanism on the enhanced performance was discussed deeply. • The deductive degradation pathway of levofloxacin was also proposed. [ABSTRACT FROM AUTHOR]

Abstract: ZnIn2S4 microspheres have been synthesized by a facile hydrothermal method at 80°C. The characterization results show that the as-synthesized sample is hexagonal phase ZnIn2S4 microspheres. The results of elemental mapping and thermogravimetric confirm that the sample is the pure ZnIn2S4. The ZnIn2S4 sample has been first used as visible-light-driven photocatalyst for selective oxidation of benzyl alcohol to benzaldehyde under ambient conditions, which shows the conversion is ca. 69% along with the high selectivity, ca. 94%, after 3h irradiation. XRD and XPS investigations suggest that ZnIn2S4 is relatively stable in the photocatalytic reaction. [Copyright &y& Elsevier]

• Novle La 2 Ti 2 O 7 /Bi 5 O 7 I composite photocatalysts were synthesized. • The photocatalyst exhibited much higher performance for CIP degradation under visible light. • The apparent rate constant for CIP degradation was 57.7 times and 12.3 times as that of La 2 Ti 2 O 7 and Bi 5 O 7 I. • The mechanism on the enhanced performance was discussed deeply. The La 2 Ti 2 O 7 /Bi 5 O 7 I (LB) composite photocatalyst was synthesized by an in-situ growth method. The microstructure, optical properties, and energy band structure of the prepared photocatalysts were studied by a series of characterization methods. The photocatalytic activity was studied by degrading ciprofloxacin (CIP) under visible light. The effects of hybrid ratio (La 2 Ti 2 O 7 /Bi 5 O 7 I) on photocatalytic activity were investigated. The results showed that the composite photocatalyst exhibited better photocatalytic activity than the corresponding single component (La 2 Ti 2 O 7 or Bi 5 O 7 I). Among them, the LB-2 composite photocatalyst showed the optimal photocatalytic efficiency (reaction rate constant of 0.09403 min−1), which was 57.7 times and 12.3 times as that of La 2 Ti 2 O 7 and Bi 5 O 7 I, respectively. The enhanced activity of the composite photocatalyst was mainly ascribed to the formed heterojunction between La 2 Ti 2 O 7 and Bi 5 O 7 I. Finally, according to the data analysis and energy band theory, the possible charge transfer mechanism of La 2 Ti 2 O 7 /Bi 5 O 7 I composite photocatalyst was proposed. The degradation mechanism of CIP was also proposed based on the intermediates detected by LC-MS. [ABSTRACT FROM AUTHOR]

Abstract: Bi-doped hollow titania spheres were prepared using carbon spheres as template and Bi-doped titania nanoparticles as building blocks. The Bi-doped titania nanoparticles were synthesized at low temperature. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV–vis diffuse reflectance spectrum (DRS) and X-ray photoelectron spectroscopy (XPS). The effects of Bi content on the physical structure and photocatalytic activity of doped hollow titania sphere samples were investigated. Results showed that there was an optimal Bi-doped content (4%) for the photocatalytic degradation of methylene blue (MB). [Copyright &y& Elsevier]

Abstract: Ceria, prepared by a precipitation method, was used as a new photocatalyst under UV light irradiation. The as-prepared sample was characterized by XRD and SEM. Results showed that the ceria was cubic fluorite structure and sized in nanometer range. The photocatalytic degradation of phenol was investigated in the presence of a suspended mixture of ceria and activated carbon. A synergy effect was observed with an enhancement of the apparent rate constant by a factor of 5.6 times. The apparent quantum yield of the ceria–AC system was also increased 2.9 times. The activated carbon with strong adsorption activity provided sites for the adsorption of phenol. Then, the adsorbed phenol would migrate continuously to the surface of ceria particles. Some phenol still remained adsorbing on the catalyst when no traces of phenol were detected in the solution. This adsorbed phenol could be degraded by maintaining UV-irradiation. [Copyright &y& Elsevier]

Abstract: A V-doped titania–activated carbon composite film was prepared by a modified sol–gel method under mild condition. X-ray diffraction analysis revealed that the titania was a pure anatase phase. From scanning electron microscopy and N2 adsorption–desorption measurements, we found that the composite film was porous since it formed a micro–nano structure. The photocatalytic activity of such film was evaluated through degradation of azo-dye Reactive Brilliant Red under visible light, and was compared to commercially available TiO2, pure titania and vanadium-doped titania films. Results showed that the photocatalytic activity was enhanced a lot. It was due to expansion of the absorption edge by vanadium doping, and the synergistic effect of activated carbon with titania. Furthermore, the hydrophilic property of the as-prepared composite film was superior to other samples. [Copyright &y& Elsevier]

Abstract: N-doped TiO2 nanotube arrays (NTN) were prepared by anodization and dip-calcination method. Hydrazine hydrate was used as nitrogen source. The surface morphology of samples was characterized by SEM. It showed that the mean size of inner diameter was 65nm and wall thickness was 15nm for NTN. The ordered TiO2 nanotube arrays on Ti substrate can sustain the impact of doping process and post-heat treatment. The atomic ratio of N/Ti was 8/25, which was calculated by EDX. Photoelectrochemical property of NTN was examined by anodic photocurrent response. Results indicated the photocurrent of NTN was nearly twice as that of non-doped TiO2 nanotube arrays (TN). Photocatalytic activity of NTN was investigated by degrading dye X-3B under visible light. As a result, 99% of X-3B was decomposed by NTN in 105min, while that of TN was 59%. [Copyright &y& Elsevier]

Abstract: N-doped titania hollow spheres (NTHS) were prepared by a one-pot hydrothermal method using urea as precursor of nitrogen. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectrum (DRS). The photocatalytic activity of as-prepared titania hollow spheres was determined by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation, and was compared to non-doped titania hollow spheres and commercial P25 titania. Results indicated that the as-prepared NTHS showed highest photocatalytic activity. [Copyright &y& Elsevier]

Abstract: A novel photocatalyst (Ce, C-codoped titania) was synthesized through a modified sol–gel method under mild condition. The as-prepared sample was investigated by XRD, SEM, DRS and XPS. It was found that the as-prepared photocatalyst was composed of spheroidal particles, which were smaller than undoped ones. The absorbance spectrum of Ce, C-codoped TiO2 exhibited significant red-shift to visible region. It can be ascribed to appearance of a new electronic state in the middle of the TiO2 band-gap. Furthermore, cerium doping could slow the radiative recombination process of photogenerated electrons and holes in TiO2. Accordingly, for degradation of dye Reactive Brillint Red X-3B (C.I. reactive red 2) under visible light, the photocatalytic activity of Ce, C-codoped TiO2 improved much compared to other samples (C-doped TiO2, undoped TiO2 and P25). [Copyright &y& Elsevier]

Abstract: Nanocrystalline mesoporous titania was synthesized via a combined sol–gel process with surfactant-assisted templating method using cetyltrimethyl ammonium bromide (CTAB) as the structure-directing agent. The process was catalyzed by different acid (hydrochloric acid, nitric acid, sulfuric acid, or phosphoric acid). The prepared samples were characterized by XRD, TEM, BET and FT-IR. The photocatalytic activity of the samples was determined by degradation of phenol in aqueous solution. Results showed that different acid had different effect on the structure and crystal phase of the samples. The sample adjusted by phosphoric acid showed highest surface area and photocatalytic activity. The formation mechanism of the samples catalyzed by different acid was also discussed. [Copyright &y& Elsevier]

Abstract: A visible light active photocatalyst was prepared through boron-doping by using sodium borohydride as boron source. Different from the previous boron-doped titania prepared at high temperature, our preparation was carried out at 55°C under hydrothermal condition. The as-prepared boron-doped titania was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscope, diffuse reflection spectra and N2 adsorption–desorption measurements. The results showed that diboron trioxide phase appeared in the X-ray diffraction pattern of such photocatalyst. Compared to boron-doped titania synthesized by sol–gel method and pure TiO2, this novel photocatalyst exhibited stronger absorption in the visible region, and it also showed larger surface area. The photocatalytic activity was evaluated for degradation of Reactive Brilliant Red (C.I. Reactive Red 2) and 4-chlorophenol under visible light irradiation, respectively. The trend of photocatalytic activity was as follows: boron-doped titania (hydrothermal method)>boron-doped titania (sol–gel method)>pure titania>Degussa P25. [Copyright &y& Elsevier]

N-doped titania hollow spheres were prepared using hydrothermally prepared carbon spheres as template. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectrum (DRS). The photocatalytic activity of as-prepared hollow titania spheres was determined by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation, and was compared to commercial P25 titania. It was revealed that the photocatalytic activity of the titania hollow spheres enhanced a lot. The apparent rate constant of the titania hollow spheres was almost 17 times as that of P25 titania. [Copyright &y& Elsevier]

Abstract: A novel magnetically separable composite photocatalyst (N-doped titania-coated γ-Fe2O3 magnetic activated carbon) was prepared. It consists of N-doped titania, activated carbon and γ-Fe2O3. The whole processes were carried out under low temperature. The prepared sample was characterized by XRD, DRS, SEM, BET and vibrating sample magnetometer (VSM). The photocatalytic activity was determined by degradation of Reactive Brilliant Red X-3B in an aqueous solution under solar irradiation. Results showed that this as-prepared composite photocatalyst exhibited much higher photocatalytic activity than Degussa P25. Furthermore, the photocatalyst can be separated easily by an external magnetic field. Thus, the photocatalyst can be recycled without mass losing, and the degradation percent of X-3B decreased less than 2% after six cycles. [Copyright &y& Elsevier]

Abstract: C,N,S-tridoped mesoporous titania was synthesized via a combined sol–gel process with surfactant-assisted templating method using cetyltrimethylammonium bromide (CTAB) as the structure-directing agent. The prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectra (DRS), N2 adsorption–desorption measurements (BET) and Fourier transform infrared spectroscopy (FT-IR). The photocatalytic activity was evaluated by the photocatalytic degradation of Reactive Brilliant Red X-3B in aqueous solution. The results showed that the prepared titania was mesoporous structured and exhibited stronger absorption in the visible light region with red shift in the absorption edge. The prepared C,N,S-tridoped mesoporous titanias showed high photocatalytic activity under visible light irradiation. The high activity can be attributed to the synergetic effects of large surface area, red shift in absorption edge, strong absorption in visible light region and mixed phase structures of the C,N,S-tridoped mesoporous titania. [Copyright &y& Elsevier]

Abstract: The present work was focused on photocatalytic oxidation of the model molecule reactive brilliant X-3B by lanthanide-modified TiO2 samples under artificial solar and UV irradiation. Experimental results showed that the TiO2 samples doping with lanthanide (Ce and Gd) could greatly enhance the activity of pure TiO2, and could extend the absorption range to visible region. The optimum doping amount was 0.2 and 0.5at.% for Ce- and Gd-doped TiO2 particles, respectively. The degradation kinetics of X-3B on Ce-doped TiO2, Gd-doped TiO2, and pure TiO2 were studied as well. The results exhibited that the degradation of X-3B on all the samples were in accordance with the first-order model. The trend of apparent reaction rate constants k app was as follows, Gd-doped TiO2 >Ce-doped TiO2 >pure TiO2, under solar illumination. Scatchard plot analysis was used to evaluate the adsorption phenomena of as-prepared samples, and it indicated that lanthanide doping can improve the efficiency of interfacial adsorption of TiO2 samples. The trend was the same as that of photocatalytic activity. [Copyright &y& Elsevier]

Abstract: A novel magnetically separable composite photocatalyst, titania-coated magnetic activated carbon (TMAC), was prepared by depositing of anatase titania onto the surface of magnetic activated carbon (MAC). The MAC was prepared by a simple route: directly adsorbing of magnetic Fe3O4 nanoparticles onto activated carbon. The prepared samples were characterized by XRD, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples was determined by degradation of reactive brilliant red X-3B under either UV or visible irradiation, and compared to Degussa P25. The composite photocatalyst can be separated easily from solution by a magnet, its photocatalytic activity in degradation of X-3B also has dramatic enhancement compared to that of P25 titania. The composite photocatalyst can also be reused with a little reduction of its photocatalytic activity. The degradation rates of X-3B were both higher than 80% after six cycles under UV and visible irradiation. [Copyright &y& Elsevier]

Abstract: Gadolinium (Gd)-doped titania nanoparticles were synthesized under mild condition (low temperature (<100°C) and ambient pressure) by a modified sol–gel method. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), diffuse reflectance spectra (DRS) and photoluminescence (PL) analysis. The photocatalytic activity was evaluated by degradation of dyes (Reactive Brilliant Red X-3B and rhodamine B) in aqueous solution under visible light and UV irradiation. Results showed that highly crystalline anatase Gd-doped titania was obtained without further heat post-treatment. All Gd-doped samples showed a significant shift in the onset absorption towards the longer wavelength. Appropriate amount of Gd doping could slow the radiative recombination process of photogenerated electrons and holes in TiO2. Furthermore, it exhibited a significant improvement in photocatalytic activity. The trend of the apparent rate constant under visible light was as follows, 0.5 at% Gd-doped TiO2 >0.3 at% Gd-doped TiO2 >0.7 at% Gd-doped TiO2 >pure titania>P25 (a commercial titania). [Copyright &y& Elsevier]

Abstract: An excellent visible light responsive C,N-codoped Titania hollow spheres were prepared by a simple wet method. Hydrazine was used as nitrogen resource. Firstly, Titania hollow spheres were prepared using carbon spheres as template. Afterwards, the hollow spheres were dipped into hydrazine hydrate, and then calcined at low temperature (120°C) in the air. Thus, C,N-codoped Titania hollow spheres was successfully obtained. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV–Vis diffuse reflectance spectrum (DRS). Photocatalytic activity of thus prepared C,N-codoped Titania hollow spheres were investigated by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation. A photocurrent-time spectrum was also applied to characterize the electron–transferring efficiency in the process of photocatalysis reactions. [Copyright &y& Elsevier]

• Novle Z-scheme Bi 3 NbO 7 /BiOCl composite photocatalysts were synthesized. • The photocatalyst exhibited high performance for Cr(VI) reduction and CIP degradation. • The apparent rate constant for CIP degradation was 5.1 and 14.3 times as that of BNO and BiOCl. • The apparent rate constant for Cr(VI) reduction was 33.2 and 17.6 times as that of BNO and BiOCl. • The mechanism on the enhanced performance was discussed deeply. Direct Z-scheme Bi 3 NbO 7 /BiOCl composite photocatalytic materials were fabricated via a facile hydrothermal method. The photocatalytic activity of the synthesized catalyst samples for Cr(VI) reduction and CIP degradation was investigated under visible light irradiation. The Bi 3 NbO 7 /BiOCl-2 composite showed the highest photocatalytic performance. Its apparent rate constant for photocatalytic degradation of CIP was 5.1 and 14.3 times as that of BNO and BiOCl, respectively. And the apparent rate constant for photocatalytic reduction of Cr(VI) was 33.2 and 17.6 times as that of BNO and BiOCl. The superior activity was chiefly ascribed to the Z-scheme heterojunction formed between Bi 3 NbO 7 and BiOCl, which effectively promoted the efficiency of carrier separation and migration. Furthermore, the prepared BNO/BiOCl-2 composite photocatalyst showed stable activity in four photocatalytic cycling experiments of CIP and Cr(VI). This work provided a good example for further design and preparation of other Z-scheme photocatalysts with high performance for the remediation of both organic and heavy metal pollutants. [ABSTRACT FROM AUTHOR]

Abstract: In this study, different titania films were prepared by a sol–gel spin-coating technique. By introducing nanocarbon spheres into the precursor solution, porous titania film was prepared after calcination at a temperature of 500°C for 3h. The as-prepared porous titania film was characterized by XRD, BET, TEM and SEM. The photocatalytic property of the prepared porous film was evaluated by degrading X-3B under UV irradiation. Results showed that photocatalytic performance of as-prepared porous film was much higher than that of smooth titania and P25 films. [Copyright &y& Elsevier]

Abstract: Bi2O3–TiO2 composite films were synthesized by a sol–gel method under mild condition (i.e. low temperature and ambient pressure). The as-prepared films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, infrared spectra and fluorescence spectra. The results showed that Bi2O3–TiO2 composite films were composed of anatase titania and Bi2O3. TiO2 particles were deposited on the surface of Bi2O3 to form uniform film. Incorporating Bi2O3 with TiO2 leads to increased surface OH group density. All Bi2O3–TiO2 composite films exhibited higher photocatalytic activity compared with pure TiO2 under solar irradiation, while the film with Bi/Ti atomic ratio of 1.25% showed the highest photocatalytic activity. Furthermore, the as-prepared films can be reused with little photocatalytic activity decreasing. Without any further treatment besides rinsing, the photocatalytic activity of Bi2O3–TiO2 (1.25%) films was still higher than 77% after six-cycle utilization. [Copyright &y& Elsevier]

Abstract: A novel magnetically separable composite photocatalyst, anatase titania-coated magnetic activated carbon (TMAC), was prepared in this article. In the synthesis, magnetic activated carbon (MAC) was firstly obtained by adsorbing magnetic Fe3O4 nanoparticles onto the activated carbon (AC), and then the obtained MAC was directly coated by anatase titania nanoparticles prepared at low temperature (i.e. 75°C). The prepared samples were characterized by XRD, SEM and vibrating sample magnetometer (VSM). The composite photocatalyst can be easily separated from solution by a magnet, its photocatalytic activity in degradation of phenol in aqueous solution also has dramatic enhancement compared to that of the neat titania. [Copyright &y& Elsevier]

Abstract: A simple route has been developed for the synthesis of europium, nitrogen-codoped titania photocatalysts under mild conditions (i.e., low temperature, ⩽348 K, and ambient pressure). The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectra (DRS) analyses. The results showed that the codoped photocatalyst with a spheroidal shape exhibited a smaller size than the undoped titania. The transformation from anatase to rutile was suppressed by doping with Eu and N atoms. Furthermore, the absorbance spectra of Eu, N-codoped TiO2 exhibited a significant red shift to the visible region. The photocatalytic activity of Eu, N-codoped TiO2 was evaluated by photodegradation of the dye reactive brilliant red X-3B under visible light. This codoped sample exhibited enhanced photocatalytic activity compared to N-doped TiO2, pure TiO2, and P25. [Copyright &y& Elsevier]

Abstract: Fluorine-doped anatase titania sols were synthesized by hydrolysis of titanium-n-butoxide in the presence of abundant acidic aqueous solution and using ammonium fluoride as fluorine precursors, under mild condition. The prepared fluorine-doped titania nanoparticles were loaded on activated carbon in a rotatory evaporator under vacuum to form a composite photocatalyst. X-ray diffraction, Fourier transform infrared spectrum analysis, UV–visible spectroscopy, scanning electron microscope and Brunauer–Emmett–Teller adsorption measurement were used to characterize these as-prepared powders. The photocatalytic activity of the sample was evaluated by degrading phenol under visible light. Results showed that the composite photocatalyst was porous due to its nano–microstructure. The number of hydroxyl groups on the titania surface was enhanced after fluorine doping. Compared with pure titania–activated carbon and Degussa P25, the as-prepared composite powders exhibited much higher photocatalytic activity, although absorption response range into the visible region was not detected by diffuse reflection spectra. [Copyright &y& Elsevier]

Abstract: A novel optical fiber reactor (OFR) that employs side-glowing optical fibers (SOFs) as a means of light transmission medium and TiO2 supporter has been developed, characterized, and investigated. Different from existing ones, the SOF here is made up of quartz core with a silicon cladding, which can emit light from side surface more uniformly and can transmit light for longer distance since attenuation of light through SOF is slow; furthermore, SOF is flexible enough to be entwined into U-shapes. The crystal phase and microstructure of TiO2 coating are investigated by XRD and SEM. Solar light collected and transmitted to SOF by automatic sun-tracing equipment (ASE) was utilized to excite the titania coating for photocatalytic degradation of 4-chlorophenol (4-CP). Compared to traditional solar collectors, the present one can collect solar light efficiently while occupying smaller area, moreover, ASE allows a long distance light transmission to somewhere such as indoor or sub-surface for photocatalytic applications. Results show that 79% of 4-CP had been decomposed under sunlight irradiation for 8h. [Copyright &y& Elsevier]

Abstract: Anatase titania hollow spheres were prepared using hydrothermally prepared carbon spheres as template. The prepared hollow spheres were characterized by XRD, BET, TEM, XPS and diffuse reflectance spectrum (DRS). The photocatalytic activity of the as-prepared titania hollow spheres was determined by degradation of MB in aqueous solution, and was compared to commercial P25 titania. It was revealed that the photocatalytic activity of the titania hollow spheres enhanced a lot. The apparent rate constant of the titania hollow spheres is almost 6 times as that of P25 titania. [Copyright &y& Elsevier]

Abstract: A composite photocatalyst with an anatase titania shell and a magnetite core was prepared in a novel way at low temperature (75°C at most) by coating photoactive titanium dioxide onto a magnetic Fe3O4 core. The photocatalytic activity of the prepared photocatalyst was evaluated by the degradation of model contaminated water of phenol and compared to single-phase titania (either Degussa P25 or prepared titania without magnetic Fe3O4). The results showed that the photoactivity was slightly depressed. Then, a remarkable improvement in photoactivity was achieved by modifying the photocatalyst with a SiO2 layer between the Fe3O4 core and TiO2 shell. The repetitive using of the modified photocatalyst was also investigated, and experimental results illustrated that the photocatalytic-degraded ratio of phenol was still higher than 80% after six cycles. [Copyright &y& Elsevier]

Abstract: A novel magnetically separable composite photocatalyst, titania-coated γ-Fe2O3 magnetic activated carbon, was prepared by depositing of anatase titania onto the surface of magnetic activated carbon (MAC) which was prepared by a simple route: directly adsorbing of magnetic γ-Fe2O3 nanoparticles onto activated carbon (AC). The prepared samples were characterized by XRD, SEM, BET and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples was determined by degradation of model contaminant water of phenol aqueous solution, and compared to Degussa P25. The effect of γ-Fe2O3/AC mass ratio on the photocatalytic activity was also studied. Results illustrated that photocatalyst with γ-Fe2O3/AC mass ratio of 1:7 showed the highest degradation rate, which was nearly twice to that of P25. The photocatalyst can be separated easily by an external magnetic field. It can also be re-dispersed into aqueous solution by stirring after the removing of external magnetic field. The photocatalyst can be recycled with a little decreasing of photocatalytic activity, and the degradation rate of phenol was still higher than 80% after six cycles. [Copyright &y& Elsevier]

Abstract: Anatase titania-activated carbon composite film was prepared by a simple method at low temperature (75°C at most). The film was characterized by XRD, SEM and BET analysis. Results showed that the composite film was porous because it formed a nano-micro structure. The photocatalytic activity of the composite film was determined by degradation of 4-cholophenol (4-CP) under UV irradiation, and was compared to pure titania film and P25 film. It exhibited that the photocatalytic activity of composite film enhanced a lot. The recycle ability of the composite film was also investigated. The degradation ratio which was still higher than 85% after 5 cycles, decreased only 3% compared to the first cycle. [Copyright &y& Elsevier]

Abstract: A novel and simple method for preparing F-doped anatase TiO2 (defined as FTO) film with high photocatalytic activity was developed using titanium-n-butoxide and NH4F as TiO2 and fluorine precursors under mild condition, i.e. low temperature (lower than 373K) and ambient pressure. The prepared samples were characterized by XRD, SEM, X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectrum (DRS), photoluminescence spectrum (PL) and TG–DSC analysis. The photocatalytic activity was evaluated by decomposing X-3B under artificial solar light. The results showed that the crystallinity of TiO2 was improved by F-doping. F− ions can prevent the grain growth, and the transformation of anatase to rutile phase was also inhibited. The doped fluorine atoms existed in two chemical forms, and the ones incorporated into TiO2 lattice might take a positive role in photocatalysis. Compared with surface fluorination samples, FTO film exhibited better photocatalytic activity. The high photocatalytic activity of FTO may due to extrinsic absorption through the creation of oxygen vacancies rather than the excitation of the intrinsic absorption band of bulk TiO2. Furthermore, the FTO can be recycled with little photocatalytic activity depression. Without any further treatment besides rinsing, after 6 recycle utilization, the photocatalytic activity of FTO film was still higher than 79%. [Copyright &y& Elsevier]

Abstract: Anatase titania sols were synthesized at low temperature (i.e. 75°C) by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution. The prepared TiO2 nanoparticles were loaded on activated carbon in a rotatory evaporator under vacuum, and then the composite photocatalyst was employed for the removal of phenol from water. The apparent rate constant and quantum yield of the composite photocatalyst enhanced 5 and 2.5 times, respectively, compared to single phase titania. The activated carbon with strong adsorbent activity provided sites for the adsorption of phenol, and the adsorbed phenol migrated continuously onto the surface of TiO2 particles which were located mainly at the exterior surface of the activated carbon. Some phenol remained adsorbed on the catalyst when no traces of phenol were detected in the water. This adsorbed phenol could be degraded by illuminated titania while maintaining UV-irradiation. The photocatalyst was used for six cycles with degraded rate of phenol still higher than 80%. [Copyright &y& Elsevier]

By means of TiO2-layer-on-SiO2-layer, anatase TiO2 was deposited on novel side-glowing optical fibers, which can provide side UV radiation along the whole fiber length. FE-SEM images show that the double layers adhered well to the side-glowing optical fiber, and the TiO2 coating was homogeneous and smooth. The decomposition reaction of reactive brilliant red dye X-3B on a single TiO2-coated side-glowing optical fiber indicated that the side-scattering UV light intensity was strong enough for photocatalytic oxidation reaction. Therefore, TiO2-coated side-glowing optical fibers open up a new way to use the optical fiber reactor in photocatalytic wastewater treatment. [ABSTRACT FROM AUTHOR]

Abstract: Reduced graphene oxide/Bi2WO6 (RGO–Bi2WO6) composite photocatalysts were prepared by a simple one-pot method. Namely, the reduction of graphene oxide and the growth of Bi2WO6 crystal occurred simultaneously in one single process. The obtained samples were characterized by XRD, SEM, and DRS. The photocatalytic activities of as-prepared samples was investigated by degradation of MB under visible light irradiation. An enhancement in photocatalytic activities were observed in RGO–Bi2WO6 composites compared with pure Bi2WO6. We also investigated the effect of graphene amount on the photocatalytic activity of the as-prepared composite photocatalysts. Results showed that there was an optimal amount of 2.5%. [Copyright &y& Elsevier]

Abstract: In this study, B-doped titania hollow spheres were prepared using hydrothermally prepared carbon spheres as template. The photocatalytic activity of as-prepared hollow titania spheres was determined by degradation of Reactive Brilliant Red dye X-3B (C.I. reactive red 2) under visible light irradiation, and was compared to commercial P25 titania. It was revealed that the photocatalytic activity of the hollow titania spheres enhanced a lot. The apparent rate constant of the hollow titania spheres was almost 22 times as that of P25 titania. A photocurrent–time spectrum was also applied to investigate the efficiency of electron transfer in the process of photocatalysis reactions by different samples. [Copyright &y& Elsevier]

Abstract: In this study, hollow titania film (HTF) was prepared by a sol–gel spin-coating technique using titania coated nano carbon spheres as precursor suspension. The carbon spheres were synthesized by hydrothermal method using glucose as precursor. Photoelectrochemical property of HTF was examined by anodic photocurrent response, and results showed that the photocurrent of HTF was nearly twice as that of compact titania film (CTF). The photocatalytic and photoelectrochemical applications were investigated by using HTF or CTF as photoanodes for X-3B degradation under UV irradiation. Results showed that photocatalytic and photoelectrochemical activity of HTF enhanced a lot compared to CTF. [Copyright &y& Elsevier]

Direct Z-scheme Bi 3 TaO 7 –CdS semiconductor materials were synthesized via hydrothermal method. The activity of the composites was investigated by the ciprofloxacin (CIP) degradation under visible light irradiation. Bi 3 TaO 7 –CdS composite catalysts all exhibited enhanced photocatalytic performances compared to both single photocatalysts (Bi 3 TaO 7 and CdS). The characteristics of the morphology and structure, the photoelectric properties and the composition of chemical elements of these samples have been studied extensively. Besides, capture experiments demonstrated that superoxide radical and hole worked together for the CIP degradation. The optimal catalyst exhibited stable CIP degradation activity in four cycles repeating experiments. Finally, a possible Z-scheme charge migration mechanism was proposed for the Bi 3 TaO 7 –CdS composite photocatalysts. Three possible pathways were proposed for the CIP degradation based on the detected intermediates by LC/MS. This work provided a feasible idea for the further research of Z-scheme photocatalysts for the emerging contaminants degradation. • CdS/bismuth tantalate composite photocatalysts were synthesized for the first time. • The charge transfer followed Z-scheme mechanism. • The photocatalyst exhibited enhanced performance for CIP degradation of ciprofloxacin compared to Bi 3 TaO 7 and CdS. • The mechanism for the enhanced activity was discussed deeply. • The degradation pathways were deduced based on the detected intermediates. [ABSTRACT FROM AUTHOR]

LaFeO 3 /Bi 3 NbO 7 p-n heterojunction photocatalysts were prepared successfully through an in-situ growth method. The phase structure, optical property, morphology and microstructures of the obtained samples were studied by X-Ray diffractometer (XRD), Ultraviolet–visible absorption spectrum (UV–vis DRS), photoluminescence (PL) spectroscopy, transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM). The visible light responsive photocatalytic activity of as-obtained samples were investigated by the photo-reduction of Cr (Ⅵ). The effects of preparation conditions (proportion of BNO/LFO and temperature) on the activity were studied. Results showed that the as-obtained BNO-LFO-200-5 composite behaved the best photocatalytic activity (with rate constant of 0.0212 min−1) among all the obtained samples. The rate constant was about 42.4-times and 17.7-times as that of pristine BNO (0.0005 min−1) and LFO (0.0012 min−1), respectively. The enhanced photocatalytic property of the as-prepare LaFeO 3 /Bi 3 NbO 7 composites can be ascribed to the formation of p-n junction between BNO and LFO, which significantly increased the separation efficiency of photo-excited electron-holes. • A novel LaFeO 3 –Bi 3 NbO 7 p-n heterojunction photocatalyst was prepared for the first time. • The composites exhibited significantly enhanced activity for Cr (Ⅵ) photocatalytic reduction. • The heterojunctions promote the photo-generated carriers transmission and separation. [ABSTRACT FROM AUTHOR]

• In 2 S 3 decorated KNbO 3 nanocubes were successfully fabricated for the first time. • The composites exhibited greatly enhanced activity for the degradation of organic pollutants. • The formed heterojunction enhanced the separation efficiency of photo-induced electron-hole pairs. In this work, one kind of novel visible light responsive photocatalysts, In 2 S 3 decorated KNbO 3 nanocubes (KNOIS), were successfully synthesized through a facile in-situ growth method. The performance of the obtained nanocomposites was studied by photocatalytic degradation of tetracycline hydrochloride (TC) and Rhodamine B (RhB) under the irradiation of visible light. Results illustrated that the KNOIS nanocomposites had much higher performance than pure In 2 S 3 and KNbO 3. The influence of In 2 S 3 amount on the performance of the composites was also studied. Results showed that KNOIS-10 nanocomposite exhibited the best photocatalytic efficiency for TC and RhB degradation. In the degradation of RhB, the apparent rate constant of KNOIS-10 was 0.044 min−1, which was about 22 and 11 times as that of pure KNO (0.0020 min−1) and In 2 S 3 (0.0040 min−1), respectively. The trapping experiments suggested that hydroxyl radicals and holes were two main species for the photocatalytic degradation of RhB by KNOIS. Furthermore, the mechanism on the photocatalytic activity enhancement was proposed relied on the experiments and characterization results. The formed p-n heterojunction enhanced the separation efficiency of photo-induced charges. This work would provide a good example for the preparation of niobate based composite photocatalysts with high photocatalytic activity for environmental remediation. [ABSTRACT FROM AUTHOR]

The x Fe 2 O 3 / y BiOCl ( x/y , molar ratio) composites are prepared via a facile hydrothermal process, in which the uniform Fe 2 O 3 nanocubes are well deposited on the BiOCl nanosheets. The x Fe 2 O 3 / y BiOCl shows much higher activities than BiOCl or Fe 2 O 3 for the degradation of rhodamine B (RhB) and methyl orange (MO). Specifically, the degradation rate of the 5Fe 2 O 3 /100BiOCl catalyst is 7.2 and 3.7 times as high as those of the bare BiOCl for MO and RhB, respectively. This has been mainly attributed to the formation of p/n Fe 2 O 3 /BiOCl heterojunctions. [ABSTRACT FROM AUTHOR]