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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]

Sulfonamides are commonly used antibiotics, but their residues in water bodies pose a potential threat to public health. In this study, we fabricated a 2D/2D composite heterojunction by integrating petal-like flake La2Ce2O7 with stacked slice BiOCl through an in-situ self-assembly method using hydrothermal synthesis. The physicochemical properties of the synthesized materials were systematically characterized. The photocatalytic performance of the composite photocatalyst was found to be superior to that of pure La2Ce2O7 and BiOCl, which can be attributed to the synergistic effect of both high carrier separation and mobility, which ultimately leads to the formation of a 2D/2D heterojunction interface contact between La2Ce2O7 and BiOCl. Notably, the construction of type II heterojunction helps electrons and holes to react on different semiconductors and facilitates the separation of electron–hole pairs. And the hydroxyl radicals and superoxide radicals were captured by electron spin resonance and the strong oxidizing nature of the radicals can effectively break the C–X bond, which is more favorable for the conversion degradation of sulfonamides. A possible photodegradation mechanism based on the catalyst of La2Ce2O7/BiOCl was hypothesized, providing a theoretical basis for preparing 2D/2D heterojunctions with a prominent photocatalytic activity. [ABSTRACT FROM AUTHOR]

As one of the high-capacity anodes in lithium-ion batteries (LIBs), silicon oxide (SiOx) has attracted wide attention due to its high theoretical capacity, low cost, and proper working voltage. However, the huge volume change and the intrinsic poor conductivity of SiOx still hinder the practical applications. How to address the issues is the focus of current research. In this work, firstly, hydrogen passivated Si nanosheets (Si6H6) were prepared from Zintl phase CaSi2, then, two-dimensional Ag nanoparticle modified SiOx/C nanocomposite was prepared via a facile complex redox reaction between Si6H6 and AgNO3-aniline complexing agent. In this design, aniline was served as carbon sources, and Si6H6 could be transformed to SiOx by AgNO3 in mild solution condition. The obtained Ag modified SiOx/C (SiOx/C-Ag) electrode exhibited high specific capacity (550 mAh·g−1 at 0.6 A·g−1), superior rate, and cycling performance when served as anode for LIBs. [ABSTRACT FROM AUTHOR]

Photocatalytic water splitting for hydrogen (H2) generation is a potential strategy to solve the problem of energy crisis and environmental deterioration. However, powder-like photocatalysts are difficult to recycle, and the agglomeration of particles would affect the photocatalytic activity. Herein, a direct Z-scheme CdS/WO3 composite photocatalyst was fabricated based on carbon cloth through a two-step process. With the support of carbon cloth, photocatalysts tend to grow uniformly for further applications. The experimental results showed that the H2 yield of adding one piece of CdS/WO3 composite material was 17.28 μmol/h, which was 5.5 times as compared to that of pure CdS-loaded carbon cloth material. A cycle experiment was conducted to verify the stability of the as-prepared material and the result demonstrated that the H2 generation performance of CdS/WO3 decreased slightly after 3 cycles. This work provides new ideas for the development of recyclable photocatalysts and has a positive significance for practical applications. [ABSTRACT FROM AUTHOR]

TiO2 nanotube-based photocatalytic concrete paving block was prepared, and its mechanical properties, including compressive strength and abrasion resistance, as well as photocatalytic removal of NO, were investigated. Results indicate that the compressive strength and abrasion resistance of photocatalytic concrete paving block were obviously reinforced by TiO2 nanotubes compared with TiO2 nanoparticles, which might derive from the enhanced binding force between TiO2 nanotubes and calcium–silicate–hydrate (C–S–H) gel derived from the cement hydration. Moreover, the TiO2 nanotube-based photocatalytic concrete paving block shows the best photocatalytic removal of NO among the as-prepared samples, which might result from the enhanced adsorption property for NO gas over TiO2 nanotubes, and little change of NO conversion was found before and after polishing. Overall, TiO2 nanotubes not only contribute to the reinforcement of mechanical properties of the concrete block, but also dedicated to the enhancement of photocatalytic performance for NO purification. [ABSTRACT FROM AUTHOR]

In combination of a facile and scalable solvothermal method and solid-phase reduction reactions, a novel two-dimensional black TiO2 − x nanosheet (TiO2 − x NS) with high specific surface area of 108 m2 g−1 and nearly total solar spectral absorption capability have been successfully prepared. With careful characterizations, the novel TiO2 − x NS showed enhanced electrochemical performance and visible-light photocatalytic activity than those of their white TiO2 nanosheet (TiO2 NS) precursors. The black TiO2 − x NS electrode delivered a reversible specific capacity of 160 mA h g−1 even after cycling at 0.5 C (1 C = 190 mA h g−1) for 300 times, which was significantly higher than the corresponding white TiO2 NS electrode (104 mA h g−1). Meanwhile, the TiO2 − x NS also exhibited enhanced ability of visible-light photocatalytic hydrogen production than that of the white TiO2 NS. It is expected that making white TiO2 NS into black ones is an effective way to design the photocatalysts with visible light response and the anodes with long lifetime and high rate performance in lithium ion batteries. The novel black TiO2 − x NS could find potential applications in the field of environmental management and energy storage and conversion. [ABSTRACT FROM AUTHOR]

A simple calcination approach was performed to synthesize layered K3Ti5NbO14/g-C3N4 (TNCN) composites, in which g-C3N4 was formed both within the interlayers and on the surface of N-K3Ti5NbO14. The photocatalytic activity of samples was evaluated by the visible-light photocatalytic degradation of rhodamine B (RhB). It was found that TNCN composite with a proper mass ratio of N-K3Ti5NbO14 to g-C3N4 exhibited the rapid rate of charge separation and high efficiency of light harvesting due to the synergetic effects of layered heterojunction and N doping, leading to an excellent photocatalytic activity. Especially, the in situ intercalated mono-layered g-C3N4 nanosheets can significantly increase the contact area between K3Ti5NbO14 layers and g-C3N4 nanosheets for efficient charge transfer across the interface, showing the greater effect on the enhanced photocatalytic activity. The active species trapping experiments and ESR measurements were carried out to evaluate the contribution of the active species in this photocatalytic degradation process. It was revealed that both superoxide radicals (·O2−) and holes (h+) are the main active species, while hydroxyl radicals (·OH) made a minor contribution to the photocatalytic degradation of RhB. [ABSTRACT FROM AUTHOR]

Hierarchically structured ZnO hybridized with graphitic carbon nitride (g-CN) is introduced as a new material for non-enzymatic photoelectrochemical sensing of hydrogen peroxide (HO). It is based on the measurement of the decrease in the photocurrent produced by HO which consumes the photoinduced electrons ejected by the ZnO/g-CN composite. The g-CN has a beneficial effect in extending the band width of light absorption of ZnO into the visible region and to promote the separation of the photoinduced carriers. This results in an enhanced photocurrent and high-sensitivity. The ZnO/g-CN composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectrometry, and UV-vis spectrophotometry. Under the optimized condition, the sensor has a linear response to hydrogen peroxide in the 1.3-79.8 nM concentration range, and the detection limit is 0.38 nM. The sensor is sensitive, selective, stable and can be fabricated at low costs. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]