Photocatalytic CO 2 Reduction by Near-Infrared-Light (1200 nm) Irradiation and a Ruthenium-Intercalated NiAl-Layered Double Hydroxide.

Near-infrared light-driven photocatalytic CO 2 reduction (NIR-CO 2 PR) holds tremendous promise for the production of valuable commodity chemicals and fuels. However, designing photocatalysts capable of reducing CO 2 with low energy NIR photons remains challenging. Herein, a novel NIR-driven photocatalyst comprising an anionic Ru complex intercalated between NiAl-layered double hydroxide nanosheets (NiAl-Ru-LDH) is shown to deliver efficient CO 2 photoreduction (0.887 μmol h -1 ) with CO selectivity of 84.81 % under 1200 nm illumination and excellent stability over 50 testing cycles. This remarkable performance results from the intercalated Ru complex lowering the LDH band gap (0.98 eV) via a compression-related charge redistribution phenomenon. Furthermore, transient absorption spectroscopy data verified light-induced electron transfer from the Ru complex towards the LDH sheets, increasing the availability of electrons to drive CO 2 PR. The presence of hydroxyl defects in the LDH sheets promotes the adsorption of CO 2 molecules and lowers the energy barriers for NIR-CO 2 PR to CO. To our knowledge, this is one of the first reports of NIR-CO 2 PR at wavelengths up to 1200 nm in LDH-based photocatalyst systems.