Coupling Long-Range Facet Junction and Interfacial Heterojunction via Edge-Selective Deposition for High-Performance Z-Scheme Photocatalyst

The construction of photocatalytic systems that have strong redox capability, effective charge separation, and large reactive surfaces is of great scientific and practical interest. Herein, an edge-connected 2D/2D Z-scheme system that combines the facet junction and the interfacial heterojunction to achieve effective long-range charge separation and large reactive surface exposure is designed and fabricated. The heterostructure is realized by the selective growth of 2D-layered MoS2 nanoflakes on the edge-sites of thin TiO2 nanosheets via an Au-promoted photodeposition method. Attributed to the synergetic coupling of the facet junction and the interfacial heterojunction that assures the effective charge separation, and the tremendous but physically separated reactive sites offered by layered MoS2 and highly-exposed (001) facets of TiO2 , respectively, the artificial Z-scheme exhibits excellent photocatalytic performance in photodegradation tests. Moreover, the junctional plasmonic Au nanoclusters not only act as electron traps to promote the edge-selective synthesis but also generate "hot electrons" to further boost photocatalytic performance. The Z-scheme charge-flow direction in the heterostructure and the roles of electrons and holes are comprehensively studied using in situ irradiated X-ray photoelectron spectroscopy and photodegradation tests. This work offers a new insight into designing high-performance Z-scheme photocatalytic systems.

Visible light-driven photocatalytic degradation of organic pollutants via carbon quantum dots/TiO2

The preparation process of carbon quantum dots and TiO2, and a diagram of the mechanism of the degradation of organic pollutants by composite materials under visible light.

Synthesis of anatase particles via morphological control of titanium glycerolate intermediate precursor

The morphologies of titanium glycerolate precursors were controlled to obtain anatase particles with a high surface area and large aspect ratio.

Band Gap Implications on Nano-TiO₂ Surface Modification with Ascorbic Acid for Visible Light-Active Polypropylene Coated Photocatalyst

The effect of surface modification using ascorbic acid as a surface modifier of nano-TiO₂ heterogeneous photocatalyst was studied. The preparation of supported photocatalyst was made by a specific paste containing ascorbic acid modified TiO₂ nanoparticles used to cover Polypropylene as a support material. The obtained heterogeneous photocatalyst was thoroughly characterized (scanning electron microscope (SEM), RAMAN, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and Diffuse Reflectance Spectra (DRS) and successfully applied in the visible light photodegradation of Alizarin Red S in water solutions. In particular, this new supported TiO₂ photocatalyst showed a change in the adsorption mechanism of dye with respect to that of only TiO₂ due to the surface properties. In addition, an improvement of photocatalytic performances in the visible light photodegration was obtained, showing a strict correlation between efficiency and energy band gap values, evidencing the favorable surface modification of TiO₂ nanoparticles.

Ti(IV) oxalate complex-derived hierarchical hollow TiO2 materials with dye degradation properties in water

Ti(IV)-based complexes have been demonstrated as candidates for preparing hybrid and functional materials, and have received considerable attention. In this paper, hierarchical hollow titania materials with different surface nanostructures were synthesized successfully using a hydrothermal process via the transformation of a Ti(IV) oxalate complex as a precursor. Different concentrations of ammonia were used to adjust the morphologies and crystalline forms of the hydrothermal products. The hierarchical hollow anatase titania materials, HHTM-1 (cal) and HHTM-2 (cal), have high surface areas of up to 132 m(2) g(-1) and 84 m(2) g(-1), respectively, and show superior performance for dye degradation in water.

Novel TiO2/graphene oxide functionalized with a cobalt complex for significant degradation of NOx and CO

A TiO₂/FGO composite manifests high photocatalytic properties for NO_x and CO removal as high as three times more than that of bare TiO₂.