Covalence bridge atomically precise metal nanocluster and metal-organic frameworks for enhanced photostability and photocatalysis

Metal nanoclusters (NCs) with precise structure and ultrasmall size have attracted great interests in catalysis. However, the poor stability has limited its large-scale use. Herein, we proposed the “covalence bridge” strategy to effectively connect atomically precise metal NCs and metal-organic frameworks. Benefiting from the covalent linkage, the synthesized UiO-66-NH2-Au25(L-Cys)18 showed outstanding stability after 16 h photocatalysis. Moreover, the covalence bridge created a strong metal-support interaction between the two components and provided an effective charge transport channel and thereby enhanced photocatalytic activity. UiO-66-NH2-Au25(L-Cys)18 displayed an exceptional photocatalytic H2 production rate, which is 21 and 90 times higher than that of UiO-66-NH2/Au25(PET)18 (made by physically combination) and bare UiO-66-NH2, respectively. Thermodynamic and kinetic studies demonstrated that UiO-66-NH2-Au25(L-Cys)18 exhibited higher charge transfer efficiency, lower overpotential of water reduction and activation energy barrier compared with its counterparts.