A Novel Ti <sub>12</sub> ‐Based Metal‐Organic Framework for Photocatalytic Hydrogen Evolution
Bingbing Chen, Asma Mansouri, Celia M. Rueda‐Navarro, Iurii Dovgaliuk, Philippe Boullay, Arianna Melillo, Juan José Ramírez‐Hernández, Beibei Xiao, Fan Dong, Lokuge Aravindani Fernando, G. Patriarche, Ieuan Cornu, Pierre Florian, Guillaume Maurin, Sergio Navalón, Hermenegildo Garcı́a, Georges Mouchaham, Christian Serre
Abstract
Abstract A new microporous titanium‐based metal‐organic framework (Ti‐MOF), labeled as MIP‐209(Ti) (MIP: Materials from Institute of Porous Materials of Paris), features nitro terephthalate ligands and Ti 12 O 15 oxo‐clusters, as revealed by continuous rotation electron diffraction (cRED). MIP‐209(Ti) can be obtained using two different terephthalate (1, 4‐BDC 2− ) derivatives such as NO 2 ‐BDC and 2Cl‐BDC in an eco‐friendly solvent, suggesting the isostructural versatility of Ti 12 ‐MOFs. Alternatively, its Ti‐oxo‐cluster can be tuned, similarly to MIP‐177(Ti)‐LT bearing the same Ti 12 O 15 sub‐unit. Typically, low percentage Cr 3+ doping (≤5 at%) in MIP‐209(Ti) favorably enhances the water stability. MIP‐209(Ti‐Cr)‐NO 2 shows a significant hydrogen production rate, with good reusability and stability under simulated solar light irradiation. Compared to the benchmark Ti‐MOF IEF‐11, the hydrogen production of MIP‐209(Ti‐Cr)‐NO 2 with 5 at% Cr doping has a fourfold enhancement in photocatalytic hydrogen evolution from water splitting reaction (HER) during 5 h in presence of methanol (5 812 µ mol/g cat against 1 391 µ mol/g cat ), as well as, without any noble metal co‐catalyst, a sixfold enhancement in overall water splitting reaction (OWS) (681 and 325 µ mol/g cat of H 2 and O 2 , respectively, against 94 and 53 µ mol/g cat of H 2 and O 2 , respectively). This work represents a leap forward in the synthesis of Ti‐MOFs and their practical photocatalytic applications.