Hydrogen-interstitial CuWO4 nanomesh: A single-component full spectrum-active photocatalyst for hydrogen evolution.

It is of practical and theoretical significance to realize full spectrum-active photocatalytic hydrogen (H 2 ) evolution using a single-component photocatalyst. The bottleneck is the utilization of near infrared (NIR) light with 52% of the energy in solar spectrum due to the mismatch between its low single photon energy and the large bandgaps of many photocatalysts. In fact, except for the intrinsic inter-band transition, charge-transfer transition is another strategy to produce hot electrons as a result of light excitation. Herein, charge-transfer transition is achieved in hydrogen-interstitial CuWO 4 nanomesh (H-CuWO 4 ) by introducing low-valence Cu + and W 5+ . The resulting polaron absorption produces abundant free electrons upon NIR irradiation. Meanwhile, the intrinsic inter-band transition supplies more electrons upon ultraviolet and visible (UV and Vis) irradiations. The mesh structure induced by the self-assembled orientated attachment facilitates the electron transport in the photocatalytic process. Further, the lattice stress resulting from the H intercalation raises the conduction band (CB) above the H + /H 2 potential level. CuWO 4 , incapable of realizing photocatalytic H 2 evolution, is therefore activated to be a single-component full spectrum-active photocatalyst based on the dual-channel mechanism without any assistance of cocatalysts. It exhibits an excellent H 2 evolution rate and high stability. This advance may have great potential in the future environmental and energy engineering applications. [ABSTRACT FROM AUTHOR]