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•MoS2 nanoflowers were synthesized on TiO2 NTs.•TiO2 NTs/MoS2 composite photoelectrodes exhibited the attractive photocatalytic activity.•The hydrothermal growth and photocatalytic ...mechanism were explored.
The convenient and efficient anodic oxidation method was used to grow TiO2 nanotubes (NTs) on Ti sheets as the substrate, and then ultrathin MoS2 nanosheets were assembled on TiO2 NTs to construct flower-like structure composite photocatalyst in the hydrothermal process. The abundant reactive centers in the photocatalytic reaction were attributed to the thinness and wrinkling of MoS2 nanosheets. The superior carrier separation and migration capacity of the photocatalyst was verified by electrochemical characterization and photoluminescence spectroscopy analysis. The loading amount effect of MoS2 on the degradation efficiency of RhB and MB was explored. Evidently, the ability of the photocatalyst to degrade pollutants was significantly improved, and the optimal degradation efficiency of RhB and MB reached 76.33% and 100%, respectively. Assisted by adding sacrificial agent and external voltage, the outstanding photocatalytic hydrogen evolution was detected, and the optimal H2 production could reach 900.9 μmol. The mechanism of pollutant removal and hydrogen generation by TiO2 NTs/MoS2 heterojunction was proposed and analyzed based on the energy band structure and free radical capture experiments of photocatalysts.
The efficient TiO2 NTs/Sn3O4 photocatalysts were synthesized by the hydrothermal deposition of Sn3O4 on TiO2 nanotube arrays (TiO2 NTs), and the morphology, microstructure and photocatalytic property ...were adjusted by changing the alkali kind. The TiO2 NTs/Sn3O4 prepared with NaOH exhibited the outstanding photoelectric conversion and photocatalytic environment remediation/H2 evolution. The methylene blue (MB) dye and Cr(VI) could be removed by the as-prepared photocatalysts under visible light irradiation, and •O2−/•OH radicals were the main active species for MB photodegradation. Furthermore, the high photocatalytic H2 evolution rate was as high as 6.49 μmol cm−2 h−1. The outstanding photocatalytic activity and stability of TiO2 NTs/Sn3O4 photocatalysts would exhibit attractive prospect in the wastewater remediation and electric energy/hydrogen generation.
Molybdenum disulfide (MoS2) has become a potential anode material for sodium-ion batteries (SIBs) by showing decent cell performance but it suffers poor electronic conductivity and large volume ...expansion during sodiation. Here we design a nanocomposite with hollow nitrogen doped carbon and polypyrrole modified MoS2 for improving the performance for SIBs. The designed nanocomposite shows a much-improved electronic conductivity and the design of the architecture provides sufficient channels for mass transport and accommodates large volume change. This C@MoS2@PPy anode delivers a high specific capacity of 713 mAh g−1 at 0.1 A g−1 for 100 cycles, and an excellent rate capacity of 294 mAh g−1 at 5 A g−1 for 500 cycles. This specific architecture of C@MoS2@PPy could guide the future design of the electrode material in SIBs and its superior electrochemical performance indicates the great potential application for SIBs.
Hollow C@MoS2@PPy nanocomposites were designed and fabricated using FeOOH@C as sacrificial template, which exhibit excellent cycle stability and good rate capacity. Display omitted
•Ultrathin MoS2 nanosheets confined in N-doped carbon and PPy are prepared and used as high performance electrode for SIBs.•C@MoS2@PPy with much stronger MoN bonds can effectively enhance the mechanical stability.•The N-doped carbon nanotubes and PPy provide binary channels for accelerating the Na-ion transport.•C@MoS2@PPy delivers a specific capacity of 294 mAh g−1 after 500 cycles at 5 A g−1.
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•3D flower-like Bi2MoO6/Bi5O7Br nanospheres self-assembled by nanoflakes were prepared.•The microstructures could be adjusted by the addition of CTAB surfactants.•The photocatalytic ...performance and mechanism of the S-0.15 sample were investigated.
We report the preparation and photoelectrochemical performance of three dimensional (3D) flower-like Bi2MoO6/Bi5O7Br nanosphere deposited on TiO2 NTA surface by a solvothermal method. The CTAB surfactant working as the morphology controlling reagent and bromine resource played significant roles in the Bi2MoO6/Bi5O7Br crystal growth and photocatalytic pollutant removal. The S-0.15 sample with hierarchical heterostructures showed the excellent photoelectric conversion and waste water purification properties. The visible light photocurrent and photovoltage of S-0.15 achieved 0.21 mA/cm2 and −0.37 V, and 73.43%, 47.77%, 93.81% and 69.40% of RhB, MO, MB and Cr(VI) underwent removal under solar irradiation. The O2–• radicals were the main active groups for RhB and MO decoloration, and all radicals including O2–•, •OH and hole could achieve the MB degradation. Moreover, the mechanism for the electron transportation was proposed by the calculation of energy band edge location in the triple photocatalyst. The novel triple photocatalyst with hierarchical structures would provide the platform for the efficient solar cells and photocatalysts.
BiOI nanosheets/chrysanthemum-like nanoflowers were deposited on the surface of TiO2 nanotube arrays by a SILAR method. The visible light photocurrent density of TiO2 NTs/BiOI prepared with 7 SILAR ...deposition cycles was 120.06 μA/cm2 and the photovoltage was −203.61 mV/cm2. The TiO2 NTs/TiO2 NTs/BiOI samples showed the optimal photoelectrocatalytic removal efficiencies of methyl orange, rhodamine B, methyl blue and Cr(VI).
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•Chrysanthemum-like BiOI nanoflowers were deposited on TiO2 NTs by a SILAR method.•The TiO2 NTs/BiOI photoelectrode showed the excellent photoelectrochemical properties.•The p-n heterojunction PEC mechanism of TiO2 NTs/BiOI photocatalysts was proposed.
The BiOI nanosheets/chrysanthemum-like nanoflowers were successfully deposited on the surface of TiO2 nanotube arrays (TiO2 NTs) by the successive ionic layer adsorption and reaction (SILAR) method, and the morphology and visible light response of samples with different SILAR deposition cycles were investigated in detail. The as-prepared BiOI/TiO2 NTs significantly enhanced photoelectrocatalytic (PEC) activity for the removal of Methyl orange (MO), Rhodamine B (RhB), Methylene blue (MB) and Cr(VI). The as-prepared Sample-7 with chrysanthemum-like nanostructures showed the high visible light photocurrent density of 120.06 μA/cm2, photovoltage of −203.61 mV/cm2, PEC efficiencies of 45%, 62%, 79% and 77% for the removal of MO, RhB, MB and Cr(VI), respectively. The high PEC performances could be ascribed to the excellent visible light response and charge carrier transportation in chrysanthemum-like BiOI nanoflowers. By further probing the charge separation and transportation behaviors, the experiments of the energy band structure and active species trapping were carried out. A possible p-n heterojunction photocatalytic mechanism was proposed, which not only benefited the efficient separation of photogenerated electrons but also demonstrated the advanced capacity for the PEC removal of organic dyes and heavy metal ions.
Currently, the silver-based semiconductor modified TiO2 nanotube arrays (TiO2 NTA) for the improved photocatalytic treatment of industrial waste water have been a hot topic. The simple synthesis and ...environmental application of photocatalysts with excellent photocatalytic ability is still a big challenge. Herein, We reported the successive ionic layer adsorption and reaction (SILAR) preparation of Ag2O nanoparticles on TiO2 NTA surfaces. The different deposition cycles were performed to investigate the influence of Ag2O deposition amounts on the photoelectrochemical activity. Results revealed that the S-10 fabricated with 10 SILAR cycles had the impressive photocatalytic and photoelectric conversion performances. The visible light photovoltage and photocurrent of S-10 electrode were −0.20 V and 463.2 μA/cm2. Moreover, the photocatalytic degradation efficiencies of MO, RhB and MB dyes achieved 67.40%, 59.19% and 93.89%, respectively. Further increasing the irradiation time, the mineralization degree of organic dyes were improved up to 71.28%, 60.31%, and 92.58% after 6 h solar irradiation. Cr(VI) ions were also dramatically removed by photocatalysts. The remarkable photocatalytic performance of Ag2O/TiO2 NTA would exhibit attractive prospect in the industrial waste water purification.
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•Ag2O nanoparticles were deposited on TiO2 NTA by a SILAR method.•The Ag2O/TiO2 NTA showed the attractive photocatalytic activity.•The active group and photocatalytic mechanism were investigated.
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•The Bi2WO6/Bi2MoO6 heterojunctions were synthesized on TiO2 NTs.•TiO2 NTs/ Bi2WO6-Bi2MoO6 photoelectrodes displayed the attractive photocatalytic performance.•The direct Z-scheme ...photocatalytic mechanism was explored.
In this paper, the direct Z-scheme Bi2WO6-Bi2MoO6 heterojunctions were constructed by the simple hydrothermal deposition on TiO2 nanotube arrays (TiO2 NTs). The results revealed Bi2WO6/Bi2MoO6 heterojunctions dramatically enhanced the solar absorption and slowed the electron recombination, which improved the photoelectrocatalytic pollutant removal property, and •OH and •O2 radicals were the decisive active species. Moreover, the TiO2 NTs/Bi2WO6-Bi2MoO6 photoelectrode exhibited excellent photoelectric conversion and photoelectrocatalytic H2 evolution properties, much higher than the data of TiO2 NTs/Bi2WO6 and TiO2 NTs/Bi2MoO6 photoelectrodes. The visible light photoelectrocatalytic H2 evolution rate of TiO2 NTs/Bi2WO6-Bi2MoO6 photoelectrode was 38.03 μmol·h−1·cm−2, and it still showed high photocatalytic activity after several experimental cycles. The outstanding photocatalytic activity of TiO2 NTs/Bi2WO6-Bi2MoO6 sample provides a referential template of the Z-scheme heterojunction construction for the application in photocatalytic pollutant removal and H2 evolution.
Vertical grown BiOI nanosheets were fabricated by the solvothermal deposition on the surface of TiO2 nanotube arrays (TiO2 NTs)/Ti meshes for the enhanced photocatalytic removal of organic dyes and ...heavy metal ions. The BiOI nanosheets with different size and distribution were prepared by changing the reagent concentration. The photoelectrochemical results illustrated that the TiO2 NTs/BiOI (0.05) prepared with Bi3+ concentration of 0.05 mol/L showed the uniform nanosheet structure, strong solar absorption, high photocurrent generation, low interface resistance and outstanding photocatalytic property. The visible light photocurrent and photovoltage achieved 114.33 μA/cm2 and -0.24 V, and the photocatalytic removal efficiencies of MO, RhB, MB and Cr (VI) achieved 92.22%, 97.28%, 96.57% and 70.51%, respectively. Moreover, the photocatalytic stability, active group and electron transfer mechanism were also investigated. The TiO2 NTs/BiOI heterojunction provided the effective charge carrier transportation path, which dramatically inhibited the combination and consumption of electrons. The design and construction of TiO2 NTs/BiOI electrodes identified the strategy for the efficient photocatalytic pollution treatment.
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•BiOI nanosheets were loaded on TiO2 NTs surface by a simple solvothermal method.•The TiO2 NTs/BiOI photoelectrodes showed the excellent photoelectric activity.•The photocatalytic mechanism of TiO2 NTs/BiOI heterojunctions was proposed.
One dimensional CNTs@C@MFe2O4 (M = Ni, Co) composites have been rationally designed and fabricated via a facile solvothermal method and a calcination process. In the unique structure, amorphous ...carbon served as binder can increase the loading of MFe2O4 on CNTs and strengthened the binding of MFe2O4 and CNTs. As anode materials for lithium ion batteries, the CNTs@C@MFe2O4 delivers a high specific capacity, excellent cycling stability and high rate capacity. The enhanced electrochemical performance can be attributed to the uniform dispersion of MFe2O4 nanoparticles on the amorphous carbon coated CNTs, which can improve contact area between the MFe2O4 nanoparticles and the electrolyte, enhance electrical conductivity, buffer the volume change maintain the structural integrity of the electrodes. Meanwhile, the lithiation and delithiation processes are systematically investigated by X-ray photoelectron spectroscopy analysis and transmission electron microscope technique. Furthermore, the efficient synthesis process developed here can also be extended to design and synthesize other transition metal oxides/carbon nanotube functional materials.
One dimensional CNTs@C@MFe2O4 (M = Ni, Co) hybrids have been synthesized using a facile approach. The amorphous carbon on the surface of CNTs strengthens the binding of MFe2O4 and CNTs and inhibits the agglomeration of MFe2O4 nanoparticles. As a result, the CNTs@C@MFe2O4 exhibits high specific capacity, excellent cycling stability, and superior rate capacity. Display omitted
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