Highly selective and high-performance osmotic power generators in subnanochannel membranes enabled by metal-organic frameworks

Abstract

The electric organs of electric eels are able to convert ionic gradients into high-efficiency electricity because their electrocytes contain numerous “subnanoscale” protein ion channels that can achieve highly selective and ultrafast ion transport. Despite increasing awareness of blue energy production through nanochannel membranes, achieving high-performance energy output remains considerably unexplored. Here, we report on a heterogeneous subnanochannel membrane, consisting of a continuous UiO-66-NH2 metal-organic framework (MOF) and a highly ordered alumina nanochannel membrane. In the positively charged membrane, the angstrom-scale windows function as ionic filters for screening anions with different hydrated sizes. Driven by osmosis, the subnanochannel membrane can produce an exceptionally high Br−/NO3− selectivity of ~1240, hence yielding an unprecedented power of up to 26.8 W/m2 under a 100-fold KBr gradient. Achieving ultrahigh selective and ultrafast osmotic transport in ion channel–mimetic MOF-based membranes opens previously unexplored avenues toward advanced separation technologies and energy-harvesting devices.

Nanofluidic osmotic power generators – advanced nanoporous membranes and nanochannels for blue energy harvesting

“… 221–223 For example, for nanoporous membranes based on metal–organic frameworks (MOF) with pore sizes around 6–7 Å it was shown that counter-ions with a size lower than the pore size of the MOF are able to pass through the MOF porosity yielding higher ion fluxes and selectivity. 224 Consistently, the transport across the porous MOF in the case of counter-ions with larger hydrated sizes is more restricted which leads to a detriment in the power capabilities. Quantitative results of different upscaled MOF-based membranes will be addressed in more detail in Section 7.2.…”

“… 169,218,219,250–255 Liu et al developed a highly selective nanoporous membrane based on the integration of the MOF UiO-66-NH 2 onto the surface of a highly ordered AAO membrane (UiO-66-NH 2 –AAO). 224 The composite membrane was created by in situ growth of the MOF UiO-66-NH 2 onto a pre-synthesized AAO membrane modified with 3-triethoxysilylpropylamine (APTES). The previous modification of the AAO membrane with the APTES is a crucial step since it acts as a crosslinker enabling the successful integration of the MOF.…”

“… 57 Considering the up-scaled devices cited in Table 1 , only 25% of the reported systems correspond to anion-selective nanoporous membranes, which seem to be a major challenge. 224 …”

Study of the dynamic adsorption and the effect of the presence of different cations and anions on the adsorption of As(V) on GUT‐3

“…Several studies provide information on the synthesis and properties of MOFs. [4][5][6][7][8][9][10][11][12] Chueh et al [13] investigated the application prospect of MOFs in solar cells. Konnerth et al [14] reviewed the application of MOFs derived catalysts; MOFs have great application prospects in different fields because of their unique structural characteristics.…”

Preparation of Cu3(BTC)2/PVC mixed matrix membrane for pomegranate seed storage

“…Through synthesis or design by simulation (Konnerth et al, 2020), the joints (including transition metals, post-transition metals and lanthanides) and linkers (such as Bi, tricarboxylate contained benzene ring, and N-contained cycloalkane composites) have different combinations, resulting in different texture properties and morphologies of MOFs (Tranchemontagne, Mendoza-Cortes, O'Keeffe, & Yaghi, 2009). At present, MOFs are widely used in catalysis (Liao et al, 2020), sensors (Chueh et al, 2019), osmotic power generator (Liu, Yeh, Zheng, & Wu, 2021), gas separation and purification (Lai et al, 2019), and gas storage (Alezi et al, 2015). Compared with traditional inorganic porous materials, MOFs have higher porosity, specific surface area, and more abundant functional sites (Banerjee, 2012;Xue et al, 2019).…”