Surface Hydrogen Atoms Promote Oxygen Activation for Solar Light-Driven NO Oxidization over Monolithic α-Ni(OH)2/Ni Foam.

Catalysis oxidization has been known to be an effective technique in environmental remediation. However, low efficiency for oxygen activation and difficult recovery of the catalysts in powdery form significantly limit the practical application. In this work, a new-type monolithic α-Ni(OH)2/Ni-foam was fabricated by the hydrothermal process. We found that H atoms of α-Ni(OH)2 can significantly promote oxygen activation, which endows it with favorable NO and NO2 oxidization confirmed by theoretical calculation and in situ DRIFTS. Furthermore, the introduction of Ni foam accelerated the pollutant gas transfer and charge carriers' separation because of its abundant porous structure and high conductivity and its monolithic property simplified the recycling operation. Consequently, the obtained α-Ni(OH)2/Ni-foam achieved an excellent NO oxidation (69.0%) and no toxic NO2 was detected under visible light illumination (λ > 420 nm), indicating its highly promising potential in environmental remediation. Our work provides a conceptually different fresh perception to promote oxygen activation for highly efficient gas purification.