Plasmon-induced water splitting - through flexible hybrid 2D architecture up to hydrogen from seawater under NIR light.

The efficient utilization of solar energy is actual task of the present and near future. Thus, preparation of appropriate materials 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 missions. Our study provides a rationally designed 2D flexible heterostructures with photocatalytic activity for the production of "clean" hydrogen under NIR illumination with 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, further covalently grafted with metal-organic framework MIL-101(Cr). The periodic gold structure is able to efficiently support plasmon-polariton wave and to excite the hot electrons, further injected in the Pt and MIL-101(Cr) layer. The Pt and MIL-101(Cr) structure provides catalytic sites, which being saturated with hot electrons 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.