A recent study published in the journal Small focuses on the nano-engineering of carbonaceous materials such as graphene and carbon nanotubes for the production of renewable energy.
Finding green and carbon-neutral sources of energy has been a long-standing global priority to address the lingering climate crisis. To address this, carbon nanomaterials as materials for energy production and storage were seen as a potential solution.
These materials are cost effective, abundant and environmentally safe with a diverse range of binding and allotropic configurations. However, there are still several obstacles to the production and functional efficiency of these carbonaceous materials.
Photocatalytic materials for solar energy production
To address environmental concerns, interest in the development of photocatalytic nanomaterials that harness the available solar energy for pollution control applications has increased. The spontaneous production of ammonium from nitrogen (i.e. the process of reducing nitrogen) can be harnessed to generate cleaner energy using a holistic approach.
This strategy takes into account all functional aspects, including N2 engagement, charge transport to chemisorbed nitrogen, interfacial charge, energy collection and reconstruction of the active site when voltage is applied to the surface.
Use of Graphdiyne for the hydrogen evolution reaction
The process of hydrogen evolution (HER) by electrocatalytic separation of water has shown potential as an alternative energy source. Despite the excellent electrochemical properties of metal-free carbonaceous materials, a significant performance difference remains between carbon-based and metal-based electrode materials in HER.
This gap can be bridged by incorporating graphdiyne, a two-dimensional carbon monolayer composed of hybridized carbon molecules, into a three-dimensional carbon fiber array to serve as a model electrode material for determining HER function at the atomic scale. The three-dimensional permeable conductive surface is advantageous for charge transport and gas discharge efficiency, as well as providing a high electrocatalytic contact area.
Nano-engineering design scheme of carbonaceous materials for energy applications. Image credit: Ong, W.-J.
High capacity sodium-ion batteries with N2-Doped carbons
While research into renewable energy sources such as solar power has attracted a lot of attention, a major problem is that its accessibility varies widely throughout the year across the world.
As a result, a high storage system should be created to complement the growth of renewable energy technologies. This can be accomplished by using the effect of pore design and chemical composition on the nitrogen doped carbons in sodium battery cells.
Nitrogen is reported to have a beneficial effect on sodium uptake by attaching sodium ions to edge / defect regions while porous structural patterns keep sodium within. As a result, the system is very stable, retaining 90% of its bulk sodiation capacity after five cycles.
Hollow Porous Carbon Nanofibers for Li-S Batteries
Additionally, the production of distributed hollow porous carbon nanofibers (HPCNs) as sulfur hosts for Li-S electrodes has shown potential for sustainable energy production.
HPCNs can encapsulate sulfur within their highly porous surfaces, giving them superior cycling capacity, retaining 89% of their capacity after 100 cycles and achieving 99% Coulomb efficiency. Additionally, the improved efficiency is related to the improved photocatalytic efficiency, conductance and ability of the catalyst to resist the volume change of sulfur species during the charge / discharge process.
Point fault engineering of C3NOT4
Using Point Defect Engineering to Modify Graphitic Carbon Nitride C3NOT4 is an effective way to get around some of the difficulties associated with electrocatalysis for energy production. This method also applies to the use of carbon nanocomposites as anodes for Li-ion batteries.
First-principle experiments show the importance of fault reactions in nanocarbon composites. In this regard, different types of defects with 2D graphene structures and their lithium binding energy serve as indicators to influence the growth behaviors of Li.
In conclusion, there has been a desire to develop improved characterization methods to probe the production and response processes at the interface of nanomaterials. In addition, appropriate testing techniques should be established to compare and reliably assess the capabilities of these nanomaterials in several research groups globally and against commercial reactors.
Therefore, these obstacles must be overcome to push nanomaterial engineering towards higher efficiency in energy storage applications. Developing high throughput production using deep learning and data optimization is a technique to accelerate research and development in carbon nanomaterials.
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Ong, W.-J. (2021) Nano-engineered carbonaceous materials: a multifunctional platform towards a greener energy future. Small, 17(48). Available at: https://onlinelibrary.wiley.com/doi/full/10.1002/smll.202106667