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[Display omitted] • Ternary core–shell nanostructures were obtained by a facile and surfactant free method. • The resultant Pd-SNOF@SnO 2 shows efficient photoactivity for C 2 H 4 oxidation. • The core–shell structure can obviously improve the charge separation efficiency. A ternary core–shell structure composed of Sn 1.1 Nb 2 O 5.5 F 0.9 (SNOF), Pd nanoparticles, and the SnO 2 was fabricated by a facile one-step process at room temperature. In this structure, the SNOF nano-octahedrons were coated with thin layers of SnO 2 , and Pd nanoparticles were embedded in the SnO 2 matrix. The formation of SnO 2 and Pd nanomaterials was induced by the redox reaction between the reductive Sn2+ ions of the SNOF and the H 2 PdCl 4 solution. During this process, there are no organic species or foreign reducing agents involved. The as-obtained Pd-Sn 1.1 Nb 2 O 5.5 F 0.9 @SnO 2 (Pd-SNOF@SnO 2) nanocomposites showed efficient photoactivities for C 2 H 4 oxidation under simulated sunlight irradiation, which was significantly higher than that of the blank SNOF. The mineral ratio was determined to be ∼ 100%, and the catalyst was stable after five cycles. This result was ascribed to the core–shell structure of SNOF and SnO 2 as well as the embedded Pd nanoparticles functioning as an electron trapping site, which can effectively accept the photo-excited electrons. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) nanosheets are constructed. • The nanosheets exhibits a remarkable photothermal synergistic H 2 evolution rate. • Ti 0.5 Ru 0.5 O 2 shows much better co-catalytic ability compared to Ru and RuO 2. TiO 2 is an important material used in photocatalytic H 2 evolution. Here nanosheets with a Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) three-phase-junctions, composed of solid solution rutile phase Ti 0.5 Ru 0.5 O 2 , bronze phase TiO 2 (B), and anatase phase TiO 2 (A), are constructed via a hydrothermal method and subsequent calcination. At the optimal calcination temperature of 350 °C, the highest H 2 evolution rate reaches 27.817 mmol∙g−1∙h−1 at 25 °C, which is further increased up to 62.357 mmol∙g−1∙h−1 at 70 °C by synergistic photothermal catalysis. The photocatalytic activity of the optimized catalyst was further enhanced by loading with Pt as a co-catalyst. It is found that, in addition to helping charge separation, migration, and inhibiting the charge recombination, the three-phase-junctions structure is a key to present strong oxidation and reduction ability. Ti 0.5 Ru 0.5 O 2 solid solution has excellent co-catalytic ability, much better than Ru oxide, metallic Ru, as well as Pt. It works as hole acceptor, accelerating the generation and quench of photo induced peroxyl radicals, and thus significantly enhancing the H 2 generation rate. [ABSTRACT FROM AUTHOR]

• We showed the photo-corrosion process of TiO 2 nanosheet. • Facile photo-deposition method in aqueous solution was used. • TiO 2 -Au-4h(PVP) displayed the highest QE of 30.9 % and best stability. • This method can be generally valid for other nanosheet photocatalyst. Though TiO 2 was famous for good chemical stability, as an ultrathin flaky structure, TiO 2 nanosheet also got mired in photo-corrosion. Herein, we explored the inner mechanism of photo-corrosion phenomenon among nanosheet structure, and demonstrated the vital role of high specific surface area and perfect dispersity of nanosheet photo-catalyst in H 2 evolution reaction, rather than the heterophase junction of TiO 2 (B)/λ-Ti 3 O 5. Through exploring four different Conditions, we have confirmed the important modification of highly active metal co-catalyst and surfactant PVP for greatly promoted catalytic efficiency and excellent morphology, efficiency stability. In especial, sole addition of PVP not only stabilized the nanosheet morphology, also tripled the original TiO 2 (B) efficiency, while TiO 2 -Au-4h(PVP) displayed the highest QE of 30.9 %, and best stability. This work developed an excellent stable TiO 2 (B) nanosheet based catalyst, also established a possible strategy to settle photocorrosion for other nanosheet mateials under illuminated applications. Active Au and PVP modified TiO 2 (B) showed excellent morphology, efficiency stability and greatly promoted hydrogen generation. Thereinto, Au helped to transfer photo-produced electrons to proton, while PVP linked to nanosheets effectively reduced their surface energy, and protected nanosheets from restacking. [Display omitted] [ABSTRACT FROM AUTHOR]