Visible‐Light‐Driven Hydrogen Release from Layered Hydrogen Silicane

Abstract To use solar energy effectively, environmentally benign solid‐state hydrogen storage materials are sought that are capable of releasing hydrogen under visible light irradiation. The gravimetric hydrogen capacity of layered hydrogen silicane (L‐HSi) is quite high (3.44 wt.%). The optical bandgap of L‐HSi is 2.13 eV, which corresponds to a wavelength of ≈600 nm (green‐to‐yellow region). Here, visible‐light‐driven hydrogen release from L‐HSi is reported. The action spectrum of L‐HSi for hydrogen release is consistent with its absorption spectrum, indicating that hydrogen release is driven by bandgap excitation rather than the photothermal effect. The quantum efficiency of hydrogen release is 7.3% at 550 nm. Hydrogen release from L‐HSi can occur under both inert gas conditions and in the dispersed liquid form. The light intensity dependence indicates that hydrogen release is driven by low‐intensity light such as sunlight or a light‐emitting diode. L‐HSi is expected to be used as a safe, solid‐state, and lightweight hydrogen carrier with low energy consumption for hydrogen release.