TY - JOUR
T1 - Tunneling Electrical Connection to the Interior of Metal-Organic Frameworks
AU - Han, Shuangbing
AU - Warren, Scott C.
AU - Yoon, Seok Min
AU - Malliakas, Christos D.
AU - Hou, Xianliang
AU - Wei, Yanhu
AU - Kanatzidis, Mercouri G.
AU - Grzybowski, Bartosz A.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - (Figure Presented). Metal-organic frameworks (MOFs) are typically poor electrical conductors, which limits their uses in sensors, fuel cells, batteries, and other applications that require electrically conductive, high surface area materials. Although metal nanoclusters (NCs) are often added to MOFs, the electrical properties of these hybrid materials have not yet been explored. Here, we show that adding NCs to a MOF not only imparts moderate electrical conductivity to an otherwise insulating material but also renders it photoconductive, with conductivity increasing by up to 4 orders of magnitude upon light irradiation. Because charge transport occurs via tunneling between spatially separated NCs that occupy a small percent of the MOF's volume, the pores remain largely open and accessible. While these phenomena are more pronounced in single-MOF crystals (here, Rb-CD-MOFs), they are also observed in films of smaller MOF crystallites (MIL-53). Additionally, we show that in the photoconductive MOFs, the effective diffusion coefficients of electrons can match the typical values of small molecules diffusing through MOFs; this property can open new vistas for the development of MOF electrodes and, in a wider context, of electroactive and light-harvesting MOFs.
AB - (Figure Presented). Metal-organic frameworks (MOFs) are typically poor electrical conductors, which limits their uses in sensors, fuel cells, batteries, and other applications that require electrically conductive, high surface area materials. Although metal nanoclusters (NCs) are often added to MOFs, the electrical properties of these hybrid materials have not yet been explored. Here, we show that adding NCs to a MOF not only imparts moderate electrical conductivity to an otherwise insulating material but also renders it photoconductive, with conductivity increasing by up to 4 orders of magnitude upon light irradiation. Because charge transport occurs via tunneling between spatially separated NCs that occupy a small percent of the MOF's volume, the pores remain largely open and accessible. While these phenomena are more pronounced in single-MOF crystals (here, Rb-CD-MOFs), they are also observed in films of smaller MOF crystallites (MIL-53). Additionally, we show that in the photoconductive MOFs, the effective diffusion coefficients of electrons can match the typical values of small molecules diffusing through MOFs; this property can open new vistas for the development of MOF electrodes and, in a wider context, of electroactive and light-harvesting MOFs.
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U2 - 10.1021/jacs.5b03263
DO - 10.1021/jacs.5b03263
M3 - Article
C2 - 26020132
AN - SCOPUS:84935104786
SN - 0002-7863
VL - 137
SP - 8169
EP - 8175
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 25
ER -