Plasmon-Induced Water Splitting—through Flexible Hybrid 2D Architecture up to Hydrogen from Seawater under NIR Light

Abstract

The efficient utilization of solar energy is the actual task of the present and near future. Thus, the preparation of appropriate materials that are able to harvest and utilize the broad wavelength range of solar light (especially commonly ignored near-infrared light regionNIR) is the high-priority challenging mission. Our study provides a rationally designed two-dimensional (2D) flexible heterostructures with photocatalytic activity for the production of “clean” hydrogen under NIR illumination, with the hydrogen production rate exceeding most 2D materials and the ability to use the seawater as a starting material. The proposed design utilizes the hybrid bimetallic (Au/Pt) periodic structure, which is further covalently grafted with a metal–organic framework MIL-101­(Cr). The periodic gold structure is able to efficiently support the plasmon-polariton wave and to excite the hot electrons, which is further injected in the Pt and MIL-101­(Cr) layers. The Pt and MIL-101­(Cr) structures provide catalytic sites, which are saturated with hot electrons and efficiently initiate water splitting and hydrogen production. The MIL-101­(Cr) layer also serves for repelling generated hydrogen bubbles. The mechanistic studies reveal the catalytic role of every element of the 2D flexible heterostructures. The maximum hydrogen output was achieved under plasmon resonance excitation in the NIR range, and it could be actively controlled by the applied LED wavelength.

Conceptual Developments of Aryldiazonium Salts as Modifiers for Gold Colloids and Surfaces

“…[53][54][55][56][57] As a transducer of analytical signal, excimer laserinduced gratings coated by 20 nm gold film were utilized for the realization of a high plasmonsupported area of 2×1 cm. Diazonics have enabled high loading/surface coverage of functional groups on the gold surface of plasmon-active thin films, 58,59 which is considered a perfect model for the study of plasmoninduced chemical transformations using operando spectroscopy (Figure 5a-c). Utilizing these advantages, 4-ethynylphenyl grafted to a gold-coated grating via diazonium chemistry demonstrates selective reduction to double 60 and single bonds (Figure 5a), plasmon polymerization (Figure 5b), and cycloaddition of azides (Figure 5c).…”

“…Utilizing these advantages, 4-ethynylphenyl grafted to a gold-coated grating via diazonium chemistry demonstrates selective reduction to double 60 and single bonds (Figure 5a), plasmon polymerization (Figure 5b), and cycloaddition of azides (Figure 5c). [56][57][58][59][60][61][62][63]…”

Soft Plasmonics: Design, Fabrication, Characterization, and Applications

“…The design of soft plasmonic nanostructures has afforded flexible photocatalysts that can achieve solar‐to‐chemical energy transition. [ 37,38,124 ] Such designs can potentially allow further mimicking of natural soft plant systems. Figure a,b shows an example of a flexible photocatalyst obtained by integrating 2D multifunctional nanoassemblies with a soft hydrogel.…”

“…First, a discussion of various bottom‐up and top‐down fabrication methods for soft plasmonic structures and structural/mechanical/optical characterization is included ( Figure ). This is followed by the description of novel soft plasmonic material properties and applications in biological engineering, [ 34 ] flexible sensors, [ 20,35 ] flexible energy [ 36–38 ] /photonic [ 23,39 ] /electric [ 24 ] devices, and soft robotics. [ 40,41 ]…”

“…Flexible energy devices: Top: Reproduced with permission. [ 37 ] Copyright 2020, American Chemical Society. Middle and bottom: Reproduced with permission.…”