Controlled synthesis of Pt-loaded yolk–shell TiO₂@SiO₂ nanoreactors as effective photocatalysts for hydrogen generation

Abstract

Yolk–shell and hollow structures are powerful platforms for controlled release, confined nanocatalysis, and optical and electronic applications. This contribution describes a fabrication strategy for a yolk–shell nanoreactor (NR) using a post decoration approach. The widely studied yolk–shell structure of silica-coated TiO₂ (TiO₂@SiO₂) was used as a model. At first, anatase TiO₂ spheres were prepared, and subsequently were given a continuous coating of carbonaceous and silica layers. Finally, the carbonaceous layer was removed to produce a yolk–shell structure TiO₂@SiO₂. By using an in-situ photodeposition method, Pt-encased spheres (Pt-TiO₂@SiO₂) were synthesized with Pt nanoparticles grown on the surface of the TiO₂ core, which contained void spaces suitable for use as NRs. The NR showed enhanced hydrogen production with a rate of 24.56 mmol·g⁻¹·h⁻¹ in the presence of a sacrificial agent under simulated sunlight. This strategy holds the potential to be extended for the synthesis of other yolk–shell photocatalytic NRs with different metal oxides.

Graphical abstract

Keywords

nanoreactor / TiO ₂ / SiO ₂ / photocatalyst / hydrogen generation

References

[1] Teng Z, Li W, Tang Y, . Mesoporous organosilica hollow nanoparticles: synthesis and applications. Advanced Materials, 2019, 31(38): 1707612

[2] Zhu W, Chen Z, Pan Y, . Functionalization of hollow nanomaterials for catalytic applications: nanoreactor construction. Advanced Materials, 2019, 31(38): 1800426

[3] Ji L, Zheng H, Wei Y, . Temperature-controlled fabrication of Co–Fe-based nanoframes for efficient oxygen evolution. Science China Materials, 2022, 65(2): 431–441

[4] Lee J, Kim S M, Lee I S. Functionalization of hollow nanoparticles for nanoreactor applications. Nano Today, 2014, 9(5): 631–667

[5] Zuo B, Li W, Wu X, . Recent advances in the synthesis, surface modifications and applications of core–shell magnetic mesoporous silica nanospheres. Chemistry: An Asian Journal, 2020, 15(8): 1248–1265

[6] Gao C, Lyu F, Yin Y. Encapsulated metal nanoparticles for catalysis. Chemical Reviews, 2021, 121(2): 834–881

[7] Xiong S, Tang R, Gong D, . Yolk–shell catalyst: from past to future. Applied Materials Today, 2020, 21: 100798

[8] Vaz B, Salgueirino V, Perez-Lorenzo M, . Enhancing the exploitation of functional nanomaterials through spatial confinement: the case of inorganic submicrometer capsules. Langmuir, 2015, 31(32): 8745–8755

[9] Sanles-Sobrido M, Perez-Lorenzo M, Rodriguez-Gonzalez B, . Highly active nanoreactors: nanomaterial encapsulation based on confined catalysis. Angewandte Chemie International Edition, 2012, 51(16): 3877–3882

[10] Yeo K M, Choi S, Anisur R M, . Surfactant-free platinum-on-gold nanodendrites with enhanced catalytic performance for oxygen reduction. Angewandte Chemie International Edition, 2011, 50(3): 745–748

[11] Xiao M, Zhao C, Chen H, . “Ship-in-a-bottle” growth of noble metal nanostructures. Advanced Functional Materials, 2012, 22(21): 4526–4532

[12] Chen J, Bai Y, Feng J, . Anisotropic seeded growth of Ag nanoplates confined in shape-deformable spaces. Angewandte Chemie International Edition, 2021, 60(8): 4117–4124

[13] Kwon T, Kumari N, Kumar A, . Au/Pt-egg-in-nest nanomotor for glucose-powered catalytic motion and enhanced molecular transport to living cells. Angewandte Chemie International Edition, 2021, 60(32): 17579–17586

[14] Tanaka S, Nogami D, Tsuda N, . Synthesis of highly-monodisperse spherical titania particles with diameters in the submicron range. Journal of Colloid and Interface Science, 2009, 334(2): 188–194

[15] Wang S, Wang T, Chen W, . Phase-selectivity photocatalysis: a new approach in organic pollutants’ photodecomposition by nanovoid core (TiO₂)/shell (SiO₂) nanoparticles. Chemical Communications, 2008, (32): 3756–3758

[16] Wang T, Wang S, Chen W, . Chemical morphology freezing: chemical protection of the physical morphology of high photoactivity anatase TiO₂ nanotubes. Journal of Materials Chemistry, 2009, 19(27): 4692–4694

[17] Wang S, Wang T, Gao Y, . Wet photochemical filling: a new low-diameter tube-filling method based on differentiated nanotube surfaces. Journal of Materials Chemistry, 2011, 21(48): 19337–19343

[18] Mulvaney P. Surface plasmon spectroscopy of nanosized metal particles. Langmuir, 1996, 12(3): 788–800

[19] Wood A, Giersig M, Mulvaney P. Fermi level equilibration in quantum dot-metal nanojunctions. The Journal of Physical Chemistry B, 2001, 105(37): 8810–8815

[20] López R, Gómez R. Band-gap energy estimation from diffuse reflectance measurements on sol–gel and commercial TiO₂: a comparative study. Journal of Sol-Gel Science and Technology, 2012, 61(1): 1–7

[21] Munir S, Shah S M, Hussain H, . Effect of carrier concentration on the optical band gap of TiO₂ nanoparticles. Materials & Design, 2016, 92: 64–72

[22] Can E, Uralcan B, Yildirim R. Enhancing charge transfer in photocatalytic hydrogen production over dye-sensitized Pt/TiO₂ by ionic liquid coating. ACS Applied Energy Materials, 2021, 4(10): 10931–10939

[23] Wang F, Jin Z, Jiang Y, . Probing the charge separation process on In₂S₃/Pt-TiO₂ nanocomposites for boosted visible-light photocatalytic hydrogen production. Applied Catalysis B: Environmental, 2016, 198: 25–31

[24] Cao B, Li G, Li H. Hollow spherical RuO₂@TiO₂@Pt bifunctional photocatalyst for coupled H₂ production and pollutant degradation. Applied Catalysis B: Environmental, 2016, 194: 42–49

[25] Zhang J, Yu Z, Gao Z, . Porous TiO₂ nanotubes with spatially separated platinum and CoO_x cocatalysts produced by atomic layer deposition for photocatalytic hydrogen production. Angewandte Chemie International Edition, 2017, 56(3): 816–820

RIGHTS & PERMISSIONS

Higher Education Press