Sustainable carbon-based nanostructures with optoelectronic performance inspired by crustacean shells towards biomimetic pyrolysis and hydrothermal liquid crystal transfer

Abstract In this work, we exploit new sustainable carbon-based nanostructures by investigating the biomimetic pyrolysis and hydrothermal liquid crystal transfer of natural chitin nanofibrils. Chitin nanofibrils with Bouligand structure in the original crab shell are thermally carbonized to yield helical mesoporous carbon replicas. Monodisperse oleic acid-capped cobalt oxide nanoparticles are impregnated into helical pores in the carbonized membranes to generate hierarchical mesoporous Co3O4/C nanocomposites that are functionable as a freestanding, binder free supercapacitor. Towards colloidal chemistry of photoluminescent chitin-derived carbon nanoparticles, chitin nanorods prepared by acid hydrolysis of crab shell-extracted chitin disperse in water to form chitin liquid crystals that are used as a new carbon precursor for the carbonized transformation. Hydrophobic oleic acid-stabilized carbon nanorod colloids with optical response are primarily synthesized by hydrothermal phase transfer carbonization of chitin liquid crystals. The structural integrity of chitin nanorods can be preserved during liquid-liquid phase transformation to form carbon nanorods. The carbon anisotropic nanocolloids hydrophobically dispersed in toluene exhibit green photoluminescent emission in the visible region, which optically respond to trinitrotoluene. Our chitin inspiration paves a way to pursue further investigation of the electrochemical catalysis for the mesoporous Co3O4/C nanohelices and the sensing and optical coating for the photoluminescent carbon nanorod colloids.