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As a visible-light response semiconductor materials, bismuth vanadate (BiVO4) is extensively applied in photodegradation organic dye field. In this study, we synthesized C3N5 nanosheets and coupled with decahedral BiVO4 to construct a Z-scheme C3N5/BiVO4 heterostructure with close interface contact. By introducing C3N5 into BiVO4, the built Z-scheme transfer pathway provides silky channel for charge carrier migration between different moieties and enables photoexcited electrons and holes accumulated on the surface of BiVO4 and C3N5. The accelerated separation of charge carriers ensures C3N5/BiVO4 heterostructures with a powerful oxidation capacity compared with pure BiVO4. Due to the synergistic effect in Z-scheme heterostructure, the C3N5/BiVO4 demonstrated an improved photodegradation ability of rhodamine B (RhB) and methylene blue (MB) that of bare BiVO4. [ABSTRACT FROM AUTHOR]

In this study, Pt-M/WO3 (M = Cu, Co, and Ni) thin films are effectively synthesized by preparing homogeneous precursor sols, spin-coating, toluene-etching, and calcination. Furthermore, the microstructural, chemical, and electrochemical properties of the WO3, Pt-Cu/WO3, Pt-Co/WO3, and Pt-Ni/WO3 thin films are also systematically compared. The results demonstrate that when compared to the WO3 thin film, the photocatalytic capability for methylene blue (MB) solution degradation is greatly increased in the Pt-M/WO3 thin films. Transfer routes for photogenerated charges and an improved photocatalytic process are suggested based on the experimental results. Due to the large difference in the work function (Φ) between the bimetallic alloy Pt-M and WO3, a bending of the energy bands at the Pt-M/WO3 interface is presented. Furthermore, the introduction of transition metals such as Cu, Co, or Ni modifies the electronic structure of Pt-M/WO3 thin films, facilitating the separation and migration of electrons and holes. Specifically, the photogenerated electrons migrate from the CB of WO3 to Pt-Co or Pt-Ni nanoparticles in the samples of Pt-Co/WO3 or Pt-Ni/WO3 thin films, while the hot electrons from the localized surface plasmon resonance (LSPR) effect of Cu could transfer to the conduction band (CB) of WO3 and other electrons generated from the photoexcitation of the WO3 semiconductor itself in the sample of the Pt-Cu/WO3 thin film. In summary, this work proposes a unique strategy for creating electron regulation in Pt-M decorated WO3 thin films for photocatalytic application. [ABSTRACT FROM AUTHOR]

Abstract: The traditional hydrothermal method for synthesis of H2Ti3O7 nanotubes was modified, and the total hydrothermal reaction time of forming a matured network of H2Ti3O7 nanotubes was successfully decreased by 50%. The effect of hydrothermal reaction time on morphology and photocatalytic activity of H2Ti3O7 nanotubes was investigated and discussed. Various morphologies can be observed in the as-prepared samples with different hydrothermal reaction times. The photocatalytic activity of the as-prepared samples was evaluated for degradation of methyl orange (MO) under simulated solar irradiation. It was found that the sample treated in the hydrothermal condition for 36h with a matured network of H2Ti3O7 nanotubes showed excellent photocatalytic activity. The photocatalytic activity results were discussed in detail. The stronger absorption in the ultraviolet (UV) range, the increasing crystallization of H2Ti3O7 phase, and larger surface area and pore volume contributed to the enhancement of photocatalytic activity of the as-prepared samples. [Copyright &y& Elsevier]

A hydrothermal method was employed to synthesize the novel 2D/2D BiOCl/H+Ti 2 NbO 7 − heterojunction photocatalysts, showing the improved photocatalytic RhB degradation efficiency. • 2D/2D BiOCl/H+Ti 2 NbO 7 − heterojunction was synthesized by a hydrothermal route. • 2D/2D heterostructure facilitated the efficient charge separation and transfer. • BiOCl/H+Ti 2 NbO 7 − showed the high photoactivity due to heterojunction formation. • The h+ and •O 2 − played a crucial role in RhB photodegradation. To realize highly efficient removal of organic pollutant is a hot spot in environmental and energy science. Herein, we firstly prepared re-stacked H+Ti 2 NbO 7 − nanosheets (HTN) to fabricate the novel two-dimensional (2D)-2D BiOCl/H+Ti 2 NbO 7 − (BHT) heterojunctions by a hydrothermal method. The HTN were well combined with BiOCl nanoplates with an intimate interface to form a heterostructure. The rhodamine B (RhB) molecules were used as a target pollutant to evaluate the photocatalytic performance of samples under visible light. All BHT composites, with an optimal sample of BHT-4, showed the improved photocatalytic activity for degradating RhB compared with the single BiOCl and HTN. The enhanced activity was mainly attributed to the efficient charge separation and transfer, which was resulted from the formation of heterojunction between BiOCl and HTN. The produced active species can be detected by trapping experiments and ESR spectra. It indicated that hole (h+) and superoxide radical (O 2 −) played a crucial role in the photocatalytic RhB degradation, while hydroxyl radical (OH) contributed a little. A possible photodegradation mechanism was also discussed based on the corresponding experimental results. This work provides an insight for preparing 2D/2D heterojunctions with a high photocatalytic activity. [ABSTRACT FROM AUTHOR]

As a visible-light photocatalyst, bismuth iodide oxide (BiOI) is widely applied in water photocatalytic pollution degradation. However, due to the inherent high recombination rate of electron−hole pairs, an efficient photocatalytic performance could realize rarely by bare BiOI, resulting in its limited practical application. In this study, a novel type-II BiOI−C 3 N 5 heterostructure was prepared by a feasible solvothermal method to inhibit the recombination of photoexcited electrons and holes. The photocatalytic activity of the heterostructure was evaluated by degradation of tetracycline (TC) and penicillin G sodium. The results showed that compared with bare C 3 N 5 and BiOI, the photodegradation efficiency of tetracycline and penicillin G sodium was remarkable improved after heterostructure formation and the BiOI−C 3 N 5 (10% wt) samples demonstrated a higher degradation efficiency. The improvement of photocatalytic degradation activities can be attributed to the formation of type-II heterostructures with a close contact. Under the synergistic effect and interface structure in BiOI−C 3 N 5 , the spatial separation and transfer of charge carriers were increased significantly, which is in favor of enhancing the photocatalytic oxidation capacity of BiOI. [Display omitted] • A new BiOI-C 3 N 5 heterostructure was successfully constructed to heighten the photocatalytic oxidation capacity of BiOI. • Synergistic effect and interfacial fusions in BiOI −C 3 N 5 were formed for accelerating the charge carriers transfer. • The BiOI−C 3 N 5 heterostructures exhibit remarkable tetracycline (TC) and sodium penicillin G degradation performances. [ABSTRACT FROM AUTHOR]