Light-Driven Reversible Hydrogen Storage in Light-Weight Metal Hydrides Enabled by Photothermal Effect.

Requiring high temperature for hydrogen storage is the main feature impeding practical application of light metal hydrides. Herein, to lift the restrictions associated with traditional electric heating, light is used as an alternative energy input, and a light-mediated catalytic strategy coupling photothermal and catalytic effects is proposed. With NaAlH as the initial target material, TiO nanoparticles uniformly distribute on carbon nanosheets (TiO @C), which couples the catalytic effect of TiO and photothermal property of C, is constructed to drive reversible hydrogen storage in NaAlH under light irradiation. Under the catalysis of TiO @C, complete hydrogen release from NaAlH is achieved within 7 min under a light intensity of 10 sun. Furthermore, owing to the stable catalytic and photothermal effect of TiO @C, NaAlH delivers a reversible capacity of 4 wt% after 10 cycles with a capacity retention of 85% under light irradiation only. The proposed strategy is also applicable to other light metal hydrides such as LiAlH and MgH , validating its universality. The concept of light-driven hydrogen storage provides an alternative approach to electric heating, and the light-mediated catalytic strategy proposed herein paves the way to the design of reversible high-density hydrogen storage systems that do not rely on artificial energy.