Biphosphor Carbon Dots/Chlorophyll System Entirely Derived from Chlorella Microalgae for Luminescent Solar Concentrators

abstract

In this work, a singular system capable of interacting with the entire visible region of the solar spectrum is produced by combining carbon dots (CDs) and chlorophyll (Chl) pigments, entirely derived from the microalga Chlorella pyrenoidosa. The process involves the digestion of the C. pyrenoidosa cellular wall in an acetic acid:cholinium chloride (AA/ChCl) solvent, followed by a microwave reaction. The resulting CDs exhibit excitation and emission maxima at 461 and 528 nm, respectively. The Chl centers enable a secondary photoluminescence (PL) process, thus ensuring that the as-prepared CDs/Chl system (CDCS) can also interact with the farther red region of the visible spectrum. The luminescence properties of CDCS are concentration-dependent, undergoing a blue shift with dilution. Confocal microscopy provided insights into the protection of Chl pigments throughout the process. Furthermore, the consequences arising from the addition of poly(ethylene glycol) oligomers (PEG-200) are also analyzed. The results demonstrate that the interaction between CDCS and PEG-200 significantly modifies the PL intensity and emission wavelengths, especially at higher PEG-200 concentrations. This suggests that PEG-200 can act as a modulating agent, stabilizing and even preventing the CDs' fluorescence quenching while also affecting the PL properties of Chl. This work presents interesting possibilities for the development of multifunctional luminescent systems derived from microalgae biomass by addressing how these microorganisms can function not only as precursors in the formation of advanced functional materials but also as an integrated component of these systems. As an added benefit, a luminescent solar concentrator (LSC) was fabricated, revealing photostability, as well as optical and power conversion efficiency values of 11 and 0.2%, respectively, values comparable to state-of-the-art CD-based LSCs.

keywords

DEEP EUTECTIC SOLVENTS; BIOMASS PRETREATMENT; DOTS; CHLOROPHYLL; FLUORESCENCE; TEMPERATURES; DEGRADATION; BIODIESEL; MIXTURES

subject category

Science & Technology - Other Topics

authors

Santos, FM; Duarte, TAG; Correia, SFH; Pereira, RFP; Conde, A; Ribeiro, AR; Braga, SS; Ventura, SPM; Ferreira, RAS; Bermudez, VD; Nunes, SC

Groups

G2 - Photonic, Electronic and Magnetic Materials
G4 - Renewable Materials and Circular Economy

Projects

Solar-Powered Smart Windows for Sustainable Buildings (SOLPOWINS)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

acknowledgements

This study was financed by the project A-MoVeR- 'Mobilizing Agenda for the Development of Products & Systems toward an Intelligent and Green Mobility,"operation No. 02/C05- i01.01/2022.PC646908627-00000069, approved under the terms of the call No. 02/C05-i01/2022-Mobilizing Agendas for Business Innovation, financed by European funds provided to Portugal by the Recovery and Resilience Plan (RRP), in the scope of the European Recovery and Resilience Facility (RRF), framed in the Next Generation UE, for the period of 2021- 2026. The authors acknowledge the support by national funds from the Foundation for Science and Technology (FCT) and SOLPOWINS (PTDC/CTM-REF/4304/2020). This research was developed within the scope of the projects Fiber Materials and Environmental Technologies (FibEnTech-UBI) (UIDB/00195/2020 (DOI: 10.54499/UIDB/00195/2020)), Centro de Quimica-Vila Real (CQ-VR) (UIDB/00616/2020 (DOI: 10.54499/UIDB/00616/2020) and UIDP/00616/2020 (DOI: 10.54499/UIDP/00616/2020)), CICECO-Aveiro Institute of Materials UIDB/50011/2020 (DOI: 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI: 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI: 10.54499/LA/P/0006/2020), CQ-UM (UIDB/00686/2020 (DOI: 10.54499/UIDB/00686/2020) and UIDP/00686/2020 (DOI: 10.54499/UIDP/00686/2020)) and Instituto de Telecomunicacoes (UIDB/50008/2020 (DOI: 10.54499/UIDB/50008/2020), UIDP/50008/2020 (DOI: 10.54499/50008/2020) and LA/P/0109/2020 (DOI: 10.54499/LA/P/0109/2020)),financed by national funds through the FCT/MCTES (PIDDAC). LAQV-REQUIMTE (ref UIDB/50006/2020, DOI: 10.54499/UIDP/50006/2020) acknowledges funding by FCT/MCTES through national funds (PIDDAC) and, where applicable, cofinanced by the European Regional Development Fund (FEDER). F.M.S. acknowledges the SOLPOWINS project for his Junior Research contract. S.C.N. and R.F.P.P. acknowledge the FCT for the Assistant Research contracts (https://doi.org/10.54499/2020.00805. CEECIND/CP1625/CT0001 and 2023.07994.CEECIND, respectively) and S.F.H.C. also acknowledges the FCT for the Junior Research Contract (2022.03740.CEECIND/CP1716/CT0006) in the scope of Scientific Employment Stimulus.