Synthesis of chitosan-based perylene dye material for photovoltaic solar-cell application.

Renewable energy, such as solar energy, is infinite, readily available, and has extensive applications. Dye-sensitized solar cells (DSSCs) have been well developed; thus, they can be developed with low production costs, high efficiency, and facile manufacturing techniques. This study proposes a novel chitosan biopolymer-based perylene dye; the dye is modified by chitosan with perylene-3,4,9,10-tetracarboxylic anhydride using a one-pot acylation of nitrogen nucleophiles for DSSCs. The chitosan biopolymer-based perylene dyes were characterized using attenuated total reflection infrared spectroscopy, solid-state 13C CP-TOSS nuclear magnetic resonance spectroscopy, X-ray powder diffraction analysis, thermogravimetric analysis, X-ray photoelectron spectrometry, and high-resolution field-emission scanning electron microscopy. The ultraviolet-visible and fluorescence spectroscopy of chitosan biopolymer-based perylene dye exhibited a red-shift compared with perylene-3,4,9,10-tetracarboxylic anhydride and chitosan. The DSSC properties of chitosan biopolymer-based perylene dye were investigated, and it exhibited a 2.022 % power-conversion efficiency. Thus, this promising chitosan biopolymer-based perylene dye may have potential applications in solar-cell technology.

Chitosan modified multi-walled carbon nanotubes and arginine aerogel for enhanced carbon capture.

Global warming is emerging as a significant issue because of increasing CO2 levels in the atmosphere due to urbanization, industrialization, and fossil-fuel usage. Therefore, reducing atmospheric CO2 levels using new materials with high carbon capture capacity and efficient CO2 capture technologies is essential. Herein, we propose a hybrid chitosan (CS) aerogel containing multi-walled carbon nanotubes (MWCNTs) and an arginine (Arg) aerogel (CSCNTArg aerogel) for efficient carbon capture. This aerogel was successfully synthesized using a cross-linker reagent via step-freeze drying method. Fourier-transform infrared spectroscopy and X-ray diffraction analyses confirmed the successful grafting of CS, MWCNTs, and Arg onto the CSCNTArg aerogel. The thermogravimetric analysis (TGA) confirmed good thermal stability up to 500 °C of the as-developed aerogel. Field-emission scanning electron microscopy showed that the surface morphology of the CSCNTArg aerogel differed from that of CS, Arg, and MWCNTs with pores on their surfaces. N2 and CO2 adsorption-desorption studies on the CSCNTArg aerogel were performed using the Brunauer-Emmett-Teller method and TGA, respectively. The CSCNTArg aerogel showed a high adsorption capacity of approximately 5.00 mmol g-1 at 35 °C. Therefore, this new material may be useful for facilitating high-efficiency CO2 adsorption to reduce atmospheric carbon footprint.

Chitosan grafted graphene oxide aerogel: Synthesis, characterization and carbon dioxide capture study.

We have demonstrated a superficial, environmentally friendly and sustainable development of chitosan (CS) grafted graphene oxide aerogels for adsorption of CO2 gas. The CS is grafted into the carbonaceous materials like graphene oxide, multi-walled carbon nanotubes etc. to provide the large surface area, high porosity and a large number of amine group which facilitates the adsorption of CO2 gas. CS and carbonaceous materials undergo crosslinking by using cross-linker reagents, and freeze-drying technique to yield CS based aerogels with ordered porous structures. Crosslinking between CS and carbonaceous materials was confirmed by FT-IR. Physical properties of the CS-based aerogels were studied using SEM, TGA, XRD, BET isotherm analysis. The adsorption capacity of CO2 gas by CS grafted graphene oxide aerogels is around 0.257 mmol g-1 at 1 bar, that is significantly higher in comparison to the adsorption capacity of pure CS. We believe that this study helps to reduce the cost of adsorbents due to the large availability of marine waste (CS) and thus aims to reduce the anthropogenic CO2 gas at low cost, favourable temperature and pressure as compared to previously reported.