Researchers from Osaka University have developed sustainable nanocarbon materials made from crab shells, which is suitable for use in photosensors and energy storage devices.
As the demand for electronic devices increases, so does the pressure on the finite resources used in their production, such as metals and fossil fuels.
To provide renewable alternatives, researchers from Osaka University have used chitin – a biopolymer – derived from crab shells to develop a nanocarbon material for electronics applications.
Their findings were published in Journal of Materials Chemistry C.
Nanocarbon materials demonstrate considerable promise for use in electronic devices, particularly, those with porous 3D structures are able to provide efficient networks for the transport of charge, as well as electrolytes and reactants.
The flow through these networks can be additionally increased by adding imperfections — known as defects — in the form of different atoms, like nitrogen.
Efforts to use both synthetic polymers and biomass to prepare 3D porous nanocarbon with defects have led to effective sensing, energy storage, and electrocatalysis materials. However, many of these are made from non-renewable resources or require multiple steps to prepare the network and introduce the defects.
To combat the problem, the researchers have created 3D porous defective nanocarbon materials through chitin nanofibre paper. Chitin is a main element of crab shells. As the structure of chitin contains nitrogen atoms, it functions as its own source of defects and no doping steps are required.
“We were able to control various properties of the final nanocarbon materials by pyrolyzing the chitin nanofiber paper at different temperatures,” explained study first author Luting Zhu. “The pore structure, specific surface area, and electrical resistivity all varied with the pyrolysis temperature, providing us with a useful means of tuning the material for specific applications.”
The pyrolyzed chitin nanofibre papers were effectively used as photosensors — exhibiting lower resistance when exposed to light. The research also indicated that they could be used as effective supercapacitor electrodes, with greater specific capacitance than most other nanocarbon materials reported to date, which indicates their potential for use in energy storage.
“In order to translate laboratory findings into products that make a significant impact in the real world it is important to streamline processes, which is why we are excited about our simple pyrolysis treatment,” study corresponding author Hirotaka Koga added. “Furthermore, our successful use of a renewable resource that is generally considered a waste product demonstrates the viability of sustainable electronics.”