Facilely fabrication of the direct Z-scheme heterojunction of NH2-UiO-66 and CeCO3OH for photocatalytic reduction of CO2 to CO and CH4

Metal–organic framework heterojunctions for photocatalysis

“…In a recent contribution, a composite of UiO-66-NH 2 / CeCO 3 OH was constructed through an in situ growth of UiO-66-NH 2 on CeCO 3 OH. 212 Powder XRD, XPS and ESR measurements support the occurrence of a direct Z-scheme heterojunction between CeCO 3 OH and UiO-66-NH 2 , in which CeCO 3 OH and UiO-66-NH 2 are the oxidation and the reduction photocatalyst, respectively. It has been proposed that the formation of O-Zr-CO 3 2À bonds contributes positively to the performance of the heterojunction.…”

Construction of core–shell MOF@COF hybrids with a Z-scheme heterojunction for efficient visible light photocatalysis

“…This signal is likely associated with the CN bonds resulting from the condensation between the aldehyde group of TpBD-COF and the dangling amino group of NH 2 –UiO-66. 40 Indeed, the N 1s signal at 399.5 eV, corresponding to the free amino (–NH 2 ) group 37 in NH 2 –UiO-66, completely disappears after hybridization with TpBD-COF. These observations confirm the efficient hybridization of NH 2 –UiO-66 with TpBD-COF through the transformation of amine (–NH 2 ) groups into imine (CN) bonds, consistent with the FT-IR results.…”

“…2B). 37 The splitting distance of 2.3 eV corresponds to Zr 4+ in the zirconium-oxo cluster, 38 indicating the preservation of the NH 2 –UiO-66 framework during hybridization. Notably, the binding energy of the Zr 4+ species slightly decreases in NH 2 –UiO-66@TpBD-COF(21.9) compared to pristine NH 2 –UiO-66 (Fig.…”

Metal–organic frameworks in photocatalytic Z-scheme heterojunctions: an emerging technology

“…Apart from the band alignment where the CB of UIO-66-NH 2 takes part in CO 2 -RR, the presence of Ce 3+ /Ce 4+ also improves the electron transfer and provides additional catalytic active sites. 54 Since HER strongly competes with CO 2 -RR, the suppression of HER should also be considered while engineering the photocatalysts. In CuO/Ag/UiO-66, Ag acts as a bridge to promote charge transfer between the CO 2 -RR active site of CuO and the MOF, thus improving separation efficiency at the Z-scheme interface, as shown in Fig.…”

“…Apart from the band alignment where the CB of UIO-66-NH 2 takes part in CO 2 -RR, the presence of Ce 3+ /Ce 4+ also improves the electron transfer and provides additional catalytic active sites. 54…”