NH2-UiO-66(Zr) with fast electron transfer routes for breaking down nitric oxide via photocatalysis

MOFs-based photocatalysts always suffer from poor performance owing to its slow charge transfer. Herein, transient metal Cu (Cu-I/II) species were introduced to NH2 -UiO-66(Zr) (Cu-NUO) via in-situ partial reduction of Cu-II ions to Cu-I. A ligand to linker metal charge transfer (LLMCT) pathway in MOFs was constructed for accelerating the photogenerated electrons transfer from organic linkers to Cu species, greatly enhanced increasing both the carrier density value and the separation efficiency of photogenerated carriers. A longer photogenerated charge lifetime (78.2 ps) was obtained and about 4 times higher than that of Cu-NUO. More photogenerated electrons in the Cu coordinated MOFs (Cu-N137) were transferred to the outside surface of the MOFs, producing center dot O-2(-) for the photocatalytic oxidation of low-concentration (550 ppb) of NO indoor flow gas. An 88 % removal rate of NO under visible-light irradiation (lambda > 420 nm) was obtained and well maintained up to 24 h with excellent durability.