Bulk heterojunction-induced ion transport in nanochannel arrays for light-enhanced osmotic energy conversion

Abstract

Bioinspired nanochannel system showing analogous energy conversion characteristic has attracted great interest. Here, we demonstrate a nanochannels array by modifying bilayers light responsive molecules onto specific segment of alumina nanochannels....

Nanoporous anodic alumina-based iontronics: fundamentals and applications

“…The applicability of this light-responsive asymmetric NAA membrane for osmotic energy harvesting was validated with the generation of an output power density of 13.7 W m À2 at a 50-fold NaCl concentration gradient under light irradiation. 219 Another model photo-responsive osmotic system was fabricated through self-assembly of porphyrin inside the nanochannels of a NAA membrane. The BOL of NAA was opened to create tube-shaped nanopores.…”

Superstructured Optoionic Heterojunctions for Promoting Ion Pumping Inspired by Photoreceptor Cells

“…As a typical example, in the retinal cells (i.e., rod and cone photoreceptors) of vertebrate eyes, photons can alter the conformation of opsins on membrane disks by isomerizing the retinene, further inducing a visual transduction cascade and tuning the switching of ion pumps and channels (Scheme ). Especially for deep-sea fishes, photoreceptor cells have evolved a multifold structure that facilitates the layout of light-responsive combinations such as opsins and ion pumps, optimizing utilization of incident light and generating magnified electrical signals. − Scientists have been long inspired by biological ion pumps and have developed a wide variety of artificial counterparts to replicate their exquisite transport behavior using synthetic compounds and sophisticated nanostructures. − Among a diversity of energy inputs for driving artificial ion pumps, light can be readily implemented and abundant optoelectronic materials with diverse response mechanisms including photoisomerization, light-induced charge separation, and photothermal effects can be employed for designing a variety of photo-driven ion pumps, thus offering an effective dimension for ion transport manipulation. − For example, asymmetric modification of photoactive dye molecules across lamellar nanofluidic membranes can generate asymmetric charge polarization by photoisomerization reactions and move a proton uphill to accumulate a concentration gradient . Charge separation of semiconductor membranes, such as carbon nitride and porphyrin derivatives, can establish a built-in electric field upon exposure to asymmetric light irradiation, thereafter driving ion transport across the membranes. − Combining two materials with different energy levels into a Janus membrane can stabilize photoinduced charge separation between their interface and generate an enhanced transmembrane potential to facilitate ion transport in contrast to individual materials. − These inspiring developments mainly rely on the intrinsic photoresponses of various membranes to establish asymmetrical charge polarity between both ends, thus driving ion transport against a concentration gradient. − Despite these advances, however, the effect of membrane topographies on the behavior of photo-driven ion pumps remains to be explored.…”

Light-Powered Directional Ion Transport via PFN-Br/MoS2 Heterogeneous Membranes: Band Alignment and Activation Energy Barrier Engineering

“…For example, photosynthetic systems in green plants harvest sunlight and establish a proton gradient across the thylakoid membrane for ATP generation. , In this process, photosensitive pigments are excited and perform charge separation, resulting in active proton transport when excited photosensitive pigments are combined with shuttle molecules. Inspired by this natural biochemical machinery, researchers have devoted extensive efforts to develop advanced artificial light-driven ion pumps for applications in artificial photosynthesis, , ion transport regulation, , and energy conversion. , For instance, various photoresponsive molecules, including carotenoid (C)–porphyrin (P)–naphthoquinone (Q) triads, thiophene-based polymers, and ruthenium complex molecules, , have been introduced into lipid membranes or solid-state nanochannels. Moreover, photoresponsive materials such as the carbon nitride nanotube membranes and polystyrenesulfonate anion-doped polypyrrole membranes have been used to construct nanofluidic devices.…”

“…Inspired by this natural biochemical machinery, researchers have devoted extensive efforts to develop advanced artificial light-driven ion pumps for applications in artificial photosynthesis, 3,4 ion transport regulation, 5,6 and energy conversion. 7,8 For instance, various photoresponsive molecules, including carotenoid (C)−porphyrin (P)−naphthoquinone (Q) triads, 9 thiophene-based polymers, 10 and ruthenium complex molecules, 11,12 have been introduced into lipid membranes or solidstate nanochannels. Moreover, photoresponsive materials such as the carbon nitride nanotube membranes 13 and polystyr-enesulfonate anion-doped polypyrrole membranes 14 have been used to construct nanofluidic devices.…”