Surface Plasmonic Resonance and Z-Scheme Charge Transport Synergy in Three-Dimensional Flower-like Ag–CeO₂–ZnO Heterostructures for Highly Improved Photocatalytic CO₂ Reduction

Abstract

The design and engineering of plasmonic metal nanocomposite photocatalysts offer an operative approach for highly efficient CO2 photoreduction. Herein, the authors report a plasmonic 3D flower-like (3DF) Ag–CeO2–ZnO nanocomposite catalyst with effective charge carrier separation/transfer and CO2 adsorption capacity exhibiting a considerable enhanced performance compared to pure ZnO and CeO2 for photocatalytic CO2 reduction to CO and CH4 under UV–vis light. The apparent quantum efficiency of the optimized sample is 4.47% at 420 nm, and the CO2 to CO selectivity reaches up to ∼95%. The enhanced photocatalytic performance of 3DF Ag–CeO2–ZnO can be assigned to the prolonged absorption in the visible light region induced by the surface plasmon resonance (SPR) effect, the efficient separation of photogenerated charges, and the Z-scheme configuration. Furthermore, the photocatalyst displays excellent stability and reusability. The mechanism of the plasmon-mediated Z-scheme structure has been suggested in which Ag NPs act as both visible light absorber and electron mediator.

Construction of Bi2S3/TiO2/MoS2 S‐Scheme Heterostructure with a Switchable Charge Migration Pathway for Selective CO2 Reduction

“…Figure 6e shows that BTM1.5 gains the highest photocurrent response compared to the binary BTM0 and the pure Bi 2 S 3 , TiO 2 , and MoS 2 , demonstrating that the charge separation is highest in BTM1.5. [ 62 ] Furthermore, the photoluminescence (PL) spectrum of the ternary BTM1.5 exhibits the lowest intensity compared to the BTM0, BTM0.5, BTM1, BTM2, Bi 2 S 3 , TiO 2 , and MoS 2 samples. This reveals that BTM1.5 has the lowest recombination rate of the charge carriers (Figure 6f).…”

“…To further verify the charge carrier migration in the Bi 2 S 3 /TiO 2 /MoS 2 heterostructure, spin‐trapping electron spin resonance (ESR) analysis was performed in which the superoxide (•O 2 − ) and hydroxyl (•OH) radicals were detected using 5,5‐dimethyl pyrroline N‐oxide (DMPO) as the free radical trapping agent in aqueous and methanol solution, respectively. [ 8,62 ] The ESR signals of BTM1.5 for •O 2 − detection under UV–vis–NIR are shown in Figure 7d, where the signals show higher intensity than that under vis–NIR irradiation. This indicates more •O 2 − is generated under UV–vis–NIR due to higher charge carrier separation and enhanced charge accumulation band potential position (S‐scheme pathway).…”

Recent Progress and Challenges in Plasmon‐Mediated Reduction of CO2 to Chemicals and Fuels

“…Table 1 briefly summarizes the details of various plasmonic composites recently developed for photocatalytic CO 2 reduction. [20,23,39,91,97,99,[102][103][104][105][106][107][108][109][110][111][112][113]…”

Recent Advances of Photocatalytic Hydrogenation of CO2 to Methanol

“…Plasmonic metal nanoparticles with high light absorptivity have been shown to represent a new class of photocatalysts with features that differ dramatically from those of typical semiconductor photocatalysts. Plasmonic nanoparticles have unique optical, electrical, and thermal properties [99][100][101][102][103][104][105][106][107]. In this section, we focused on plasmonic photocatalysts for the photoreduction of CO 2 to methanol.…”