Au/TiO2 2D-Photonic Crystals as UV–Visible Photocatalysts for H2 Production

Noble metal decoration of wideband gap semiconductors enables the excitation of surface plasmons in the visible range that upon relaxation generate hot carriers used for catalysis. However, this strategy leads to photocatalytic conversion efficiencies that are still low. Here, a light-trapping schem...

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Detalles Bibliográficos
Autores: Torras, Miquel, Molet, Pau, Soler, Lluís, Llorca, Jordi, Roig Serra, Anna, Mihi, Agustín
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/264630
Acceso en línea:http://hdl.handle.net/10261/264630
https://api.elsevier.com/content/abstract/scopus_id/85122032407
Access Level:acceso abierto
Palabra clave:Gold nanoparticles
Hydrogen production
Photonic structures
Soft-lithography nanoimprint
Titanium dioxide
Descripción
Sumario:Noble metal decoration of wideband gap semiconductors enables the excitation of surface plasmons in the visible range that upon relaxation generate hot carriers used for catalysis. However, this strategy leads to photocatalytic conversion efficiencies that are still low. Here, a light-trapping scheme is used to amplify the light-harvesting efficiency of the TiO2 semiconductor beyond the UV region by coupling a 2D-photonic crystal to Au decorated titania. This approach is easily scalable using soft nanoimprinting lithography to prepare Au/TiO2 2D-photonic photocatalysts. In a first process, gold nanoparticles (Au NPs) are in situ infiltrated in the superficial 50 nm of a mesoporous titania (mTiO2) scaffold patterned with the photonic structure, while in a second one 2D-photonic crystals with a homogeneous volume distribution of the Au colloids are achieved. The dependence of the optical properties of the photonic crystals on the lattice parameter, geometry, and metal loading is presented through extinction measurements and analyzed through simulations. The improved photocatalytic performance of the substrates is tested for hydrogen production where a maximum of 8.5 mmol gcat−1 h−1 of H2 is recorded and attributed to photonic–plasmonic effects. These results may open new avenues in solar harvesting for hydrogen production using photonic crystals as photocatalysts.