Atomic‐Precision Tailoring of Au–Ag Core–Shell Composite Nanoparticles for Direct Electrochemical‐Plasmonic Hydrogen Evolution in Water Splitting

Abstract

Traditionally, bandgap materials are a prerequisite to photocatalysis since they can harness a reasonable range of the solar spectrum. However, the high impedance across the bandgap and the low concentration of intrinsic charge carriers have limited their energy conversion. By contrast, metallic nanoparticles possess a sea of free electrons that can effectively promote the transition to the excited state for reactions. Here, an atomic layer of a bimetallic concoction of silver-gold shells is precisely fabricated onto an Au core via a sonochemical dispersion approach to form a core-shell of Au-Ag that exploits the wide availability of excited states of Ag while maintaining an efficient localized surface plasmon resonance (LSPR) of Au. Catalytic results demonstrate that this mix of Ag and Au can convert solar energy to hydrogen at high efficiency with an increase of 112.5% at an optimized potential of −0.5 V when compared to light-off conditions under the electrochemical LSPR. This outperforms the commercial Pt catalysts by 62.1% with a hydrogen production rate of 1870 µmol g −1 h −1 at room temperature. This study opens a new route for tuning the range of light capture of hydrogen evolution reaction catalysts using fabricated core-shell material through the combination of LSPR with electrochemical means.

Plasma Ag-Modified α-Fe2O3/g-C3N4 Self-Assembled S-Scheme Heterojunctions with Enhanced Photothermal-Photocatalytic-Fenton Performances

“…The characteristic peaks of g-C 3 N 4 and α-Fe 2 O 3 are observed in the α-Fe 2 O 3 /g-C 3 N 4 composite sample, indicating that the α-Fe 2 O 3 /g-C 3 N 4 heterojunction photocatalyst was successfully prepared. The diffraction peaks of Ag were not observed in the XRD patterns of the Ag/α-Fe 2 O 3 /g-C 3 N 4 ternary composites due to the low loading of Ag nanoparticles [ 40 , 43 , 47 ]. However, in the XPS with higher sensitivity, all the characteristic peaks of the α-Fe 2 O 3 and g-C 3 N 4 appeared in the XPS survey spectrum of Ag/α-Fe 2 O 3 /g-C 3 N 4 composites, and the characteristic peaks of Ag were observed near 367 and 373 eV, indicating that the Ag/α-Fe 2 O 3 /g-C 3 N 4 ternary composites were successfully prepared ( Figure 2 b) [ 47 , 49 ].…”

“…The effect of the enhanced electric field can also extend to the space charge layer of the adjacent semiconductors, increasing the concentration of photogenerated carriers near the semiconductor surface [ 39 , 40 ]. In addition, the Schottky barrier between the metal nanoparticles and the semiconductor can promote the transfer of the charge carriers to opposite directions, further injecting energetic (hot) electrons into the semiconductor, causing a much higher concentration of energetic electrons on the surface of the photocatalyst [ 41 , 42 , 43 ]. The energy of the oscillating electrons excited by plasma resonance can be decayed by non-radiative pathways, and the high-energy electrons are coupled to the phonon mode heating the metal lattice through electron-phonon scattering.…”

Wavelength-Dependent Selective Acceleration of CO2 Reduction and H2 Evolution Using a Plasmonic Gold Nanorod Electrode

“…Photoelectrochemical solar-to-fuel conversion has been considered as a promising strategy for achieving a sustainable society. − In addition to established semiconductor-based electrodes, plasmonic electrodes have also attracted considerable attention owing to their unique light-harvesting properties associated with localized surface plasmon resonance (LSPR). − LSPR arises from the excitation of the collective oscillation of free electrons on a noble metal nanoparticle surface upon light irradiation, and hot carriers generated upon LSPR excitation have recently been reported to accelerate electrochemical reactions. − Namely, electron transfer between a plasmonic electrode and a reaction substrate can be promoted upon LSPR excitation, leading to the enhancement of electrocatalytic current under light irradiation. Furthermore, the use of a plasmonic electrode in combination with electrocatalysts enables us to accelerate an intended reaction including energy-storing reactions such as hydrogen (H 2 ) evolution, − carbon dioxide (CO 2 ) reduction, − nitrate reduction, and oxygen evolution. ,− …”

Fast Interlayer Charge Separation and Transmission in ZnIn2S4/CNTs/ZnS Heterojunctions for Efficient Photocatalytic Hydrogen Evolution

“…such as element doping, cocatalyst modifying, noble mental deposition, constructing heterojunctions, and so on. [16][17][18][19] Among many strategies to modify the performance of ZIS photocatalytic hydrogen evolution, the most successful approach is to increase photoinduced carrier separation by creating heterojunction. For instance, Tan et al synthesized WO 3 /ZIS Z-scheme heterojunction structure for photocatalytic hydrogen generation that was approximately 5.2 times that of pure ZIS.…”