Biocharring of natural fibers of insect and plant origin: a green route for the production of ‘carbon-based charge storage nanomaterials’

Abstract

Futuristic energy materials are expected to be biocompatible, green, sustainable and economical. One of the ways to develop such energy storage materials is by utilizing natural sources such as plants, animals, and insects. Autotrophs fix nitrogen and carbon in the atmosphere through rhizobium and photosynthesis, respectively, which are later consumed by animals and insects as energy sources. Biocharring these plants and insects derived products that could help us regain this carbon and nitrogen in the form of biocharred energy materials. Insect-derived Tassar cocoon, Mulberry cocoon, and Tassar silk thread give N-doped carbon matrix upon biocharring which is further processed to obtain reduced graphene oxide, whereas plant-derived Jute gives a pure carbon matrix on biocharring, all four materials show typical properties of charge storage. Exploring further on these natural charge storage materials will help the energy industries to design green charge storage systems. Further, such an approach in future will open up new avenues of business for silk and jute farmers of the world.

“Induced Electron Transfer” in Silk Cocoon Derived N-Doped Reduced Graphene Oxide-Mo-Li-S Electrode

“…All the composites showed a 2-D sheets like geometry ascertaining the presence of NDRGO matrix. In our earlier works on NDRGO and NDRGO-Li-S, we observed similar results (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018). The distribution of the chemical moieties in these complexes were further verified by their XRD signatures as shown in Figure 3.…”

“…Preparation of NDRGO Tassar silk cocoon were obtained from the forest reserves of the state of Chhattisgarh in India as described in our previous work (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018). The dead pupae was removed and the Tassar silk cocoon was cut into small pieces and was then put into a crucible.…”

“…About 0.5 g of the above sample was treated in 30 ml of hydrazine hydrate at approximately 40 • C for 12 h. The insoluble reduced graphene oxide so formed was washed with water followed by methanol and acetone sequentially and dried in a desiccator. This sample is termed as nitrogen doped reduced graphene oxide (NDRGO) (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018).…”

“…The electrode designing process was initiated from a naturally derived material of biological origin viz., Tassar silk cocoon. Bio-charred silk cocoon is a rich source of heavily nitrogen (∼16%) doped reduced graphene oxide (NDRGO) matrix, exhibiting remarkable fluorescence, soft ferromagnetism, and supercapacitor properties (Roy et al, 2014;Sahu et al, 2015;Dubey et al, 2018;Jangir et al, 2018). We discovered that doping equimolar lithium and sulfur (NDRGO-Li-S) in NDRGO matrix improves supercapacitor properties (Jangir et al, 2018).…”

“…Here it is worth highlighting the exceptional electrochemical stability of the heavily nitrogen doped carbon derived from a natural protein polymer (silk cocoon) and its transition metal sulfide composites; as stability of such composite always remained a challenge for different energy applications (Cravanzola et al, 2016;Dubey et al, 2018;Geng et al, 2018;Jangir et al, 2018;Li et al, 2018a,b,c;Luo et al, 2019;Shi et al, 2019;Zhou et al, 2019).…”