Platinum Nanoparticles Supported on TiO₂ Photonic Crystals as Highly Active Photocatalyst for the Reduction of CO₂ in the Presence of Water

Abstract

Photonic crystals can delay the propagation of light and increase its path length through a slow‐light effect, which could have immense potential in improving photocatalytic conversion efficiencies. We employed a colloidal crystal template method to synthesize TiO2 photonic crystals (PC‐TiO2), with platinum nanoparticles (Pt NPs) being deposited on the surface of the PC‐TiO2 support at different loading amounts by the gas bubbling‐assisted membrane reduction (GBMR) method. A series of Pt/PC‐TiO2 photocatalysts with well‐defined inverse‐opal structure have uniform Pt NPs (about 2.5 nm) homogeneously dispersed on the pore walls of the support. The slow‐light effect of photonic crystals effectively enhances the absorption efficiency of solar irradiation. Moreover, the Pt deposition significantly extends the spectral response and reduces the recombination rates of photoinduced electron–hole pairs. As a result, the Ptx/PC‐TiO2 catalysts exhibit excellent photocatalytic activity for the reduction of CO2 in the presence of H2O. In addition, we propose a reaction mechanism for the photoreduction of CO2 under light irradiation.

Rational Management of Photons for Enhanced Photocatalysis in Structurally-Colored Nanoporous Anodic Alumina Photonic Crystals

“…Films of nanoporous semiconductor PCs can overcome these limitations due to their robust structure and unique set of physical and chemical properties, which allows rational management of photons at the nanoscale to speed up redox reactions. The advantages of photocatalyst semiconductor PC structures make them desirable for a broad range of applications, including generation of hydrogen energy [21][22][23][24] , purification of air and water [1][2][3][4][5]25 , production of chemicals such as ammonia (NH 3 ) 26 , and carbon dioxide (CO 2 ) reduction for environmental remediation [27][28] . Nanoporous semiconductor PCs enable control of light-matter (i.e.…”

“…However, the effect of the composition and complexity of the aqueous matrix on the performance of photocatalysts is a critical aspect to consider for real-life applications and for the translation of fundamental advances in photocatalysis into practical systems that can address real-world problems. Therefore, the effect of the media composition on the photocatalytic performance of a set of TiO 2 -NAA-DBRs produced with T P = 1200 s was27 assessed studying the degradation of 4-CP in various matrices (i.e. Milli-Q H 2 O, tap H 2 O, Torrens river H 2 O, and 10 g L -1 NaCl aqueous solution).…”

Localized photodeposition of catalysts using nanophotonic resonances in silicon photocathodes

“…This effect could be explained by the fact that platinum nanoparticles act as electron-trapping centers on the surface of TiO 2 [45–46]. After the formation of the very first platinum nanoparticles, photogenerated electrons from the silicon nanostructures are transferred to TiO 2 and in sequence to the already formed platinum.…”

Photonic Crystals for Plasmonic Photocatalysis

“…Recently, plasmonic PCs have been intensively investigated to combine both PBG and LSPR effects together in terms of physical appearances and electronic energies for various applications [104][105][106][107][108][109]. An interesting study has been shown for negative photoresist IO (prepared by SiO 2 opal embedding) deposited with gold, where the dual-colored micropatterns (Figure 3) open the door for possible applications in various fields, including cosmetics, optical filters and coatings [104].…”