Transfer learning enhanced water-enabled electricity generation in highly oriented graphene oxide nanochannels

Abstract

Harvesting energy from spontaneous water flow within artificial nanochannels is a promising route to meet sustainable power requirements of the fast-growing human society. However, large-scale nanochannel integration and the multi-parameter coupling restrictive influence on electric generation are still big challenges for macroscale applications. In this regard, long-range (1 to 20 cm) ordered graphene oxide assembled framework with integrated 2D nanochannels have been fabricated by a rotational freeze-casting method. The structure can promote spontaneous absorption and directional transmission of water inside the channels to generate considerable electric energy. A transfer learning strategy is implemented to address the complicated multi-parameters coupling problem under limited experimental data, which provides highly accurate performance optimization and efficiently guides the design of 2D water flow enabled generators. A generator unit can produce ~2.9 V voltage or ~16.8 μA current in a controllable manner. High electric output of ~12 V or ~83 μA is realized by connecting several devices in series or parallel. Different water enabled electricity generation systems have been developed to directly power commercial electronics like LED arrays and display screens, demonstrating the material’s potential for development of water enabled clean energy.

Double-gradient-structured composite aerogels for ultra-high-performance moisture energy harvesting

“…4h. 9,16,[39][40][41][42][43][44][45][46] According to Table S5 (ESI †), although the above-mentioned literature demonstrated the possibility of increasing the output of MEGs by using a single gradient, the reported energy density and power density are significantly lower than the results obtained using the double-gradient structure in this study, indicating that it is an effective method to adapt doublegradient structures to improve the performance of MEGs. During the salt tolerance and stability test using the NSC@CCP aerogel, the Uoc and Isc did not decrease significantly during cycling, as shown in Fig.…”

“…Moreover, carbon materials with excellent conductivity and stability (e.g., graphene, carbon nanotubes (CNTs) and carbon quantum dots (CQDs)) are ideal functional materials for the preparation of high-performance MEGs. [5][6][7][8][9][10][11][12] However, due to their limitations of surface inertness and low content of hydrophilic active groups (e.g., amino, carboxyl, hydroxyl and sulfonic acid) in carbon materials, surface modification is often required to increase the content of hydrophilic groups on their surface and improve their wetting with water. Based on the abovementioned two aspects, it is important to construct a gradient structure inside MEGs to power the diffusion of charge carriers, thus increasing their output power.…”

“…, graphene, carbon nanotubes (CNTs) and carbon quantum dots (CQDs)) are ideal functional materials for the preparation of high-performance MEGs. 5–12 However, due to their limitations of surface inertness and low content of hydrophilic active groups ( e.g. , amino, carboxyl, hydroxyl and sulfonic acid) in carbon materials, surface modification is often required to increase the content of hydrophilic groups on their surface and improve their wetting with water.…”

A Flexible Tough Hydrovoltaic Coating for Wearable Sensing Electronics

“…Among them, DOI: 10.1002/adma.202304099 continuously generating electricity from the direct interaction between evaporationinduced waterflow and nanochannels surface without chemical reaction is regarded as an evaporation-induced hydrovoltaic effect. [2,4,5] Due to the features of spontaneity, sustainability, almost unlimited resources, and green, [6] evaporationinduced hydrovoltaic effect has attracted extensive attention and strategies have been proposed to improve the energy conversion capability, including structure design, [7][8][9][10] material properties regulation [11][12][13] and even thermal management. [14,15] In fact, the electric double layer (EDL) theory, the cornerstone of hydrovoltaic effect, indicates that the output voltage signal of hydrovoltaic device is dependent on the solution ion concentration, [16,17] which makes it possible to construct a self-powered ion sensor in addition to energy harvest.…”

Layer-by-Layer Nanofluidic Membranes for Promoting Blue Energy Conversion

“…In this technique, two fluids with varying salt concentrations are introduced on each side of a membrane. Because the two fluids have distinct Gibbs free energies, they have a tendency to mix. − Additionally, the membrane’s structure must be such that ions travel through it only in certain directions, a property known as diode-like behavior or ion current rectification (ICR), in order to extract this energy. − To achieve electroneutrality, ions must travel across the membrane, and when they do so, an electron current is generated in the external circuit, which ultimately results in the generation of energy. The aforementioned process is known as reverse electrodialysis (RED). − …”