POE-Mediated Tunable Quantum Yield of Carbon Dots-Derived From Agapanthus Africanus (L.) Hoffmann Leaves

resumo

The green synthesis of carbon dots (CDs) from natural sources is a challenging goal. Herein CDs are produced from Agapanthus africanus (L.) Hoffmann leaves by carbonization at 200/300 degrees C for 2/3 h. Samples are named CZ-X-Y, where Z, X, and Y represent carbonization, temperature, and time, respectively. CZ-200-3, CZ-300-2, and CZ-300-3 CDs have average sizes of 3.7 +/- 0.7, 5.3 +/- 1.2, and 5.1 +/- 1.6 nm, respectively. Their surface, devoid of chlorophyll, contains & horbar;OH, & horbar;C & boxH;O, and & horbar;C(& boxH;O)OH groups and sylvite. Isolated CZ-300-3 emits at 400 nm (excited at 260 nm) and exhibits an emission quantum yield (QY) value of 2 +/- 1%. Embedding in the d-U(600)/d-(900) di-ureasil matrices resulted in transparent films with emission intensity maxima at 420/450 nm (360 nm), and QY values of 7 +/- 1/16 +/- 2% (400 nm). The enhancement of the QY value of the bare CDs agrees with an efficient passivation provided by the hybrid host. The hydrophilic CZ-300-3 CDs also exerted a marked surface modifying role, changing the surface roughness and the wettability of the hybrid films.

palavras-chave

ORGANICALLY MODIFIED SILICATES; SOLID-STATE; GREEN SYNTHESIS; LIGHT; GRAPHENE; PHOTOLUMINESCENCE; HYBRIDS; EMISSION; NANODOTS; NITROGEN

categoria

Chemistry; Science & Technology - Other Topics; Materials Science; Physics

autores

Nunes, PJ; Pereira, RFP; Nunes, SC; Correia, SFH; Fu, LS; Ferreira, RAS; Fernandes, M; Bermudez, VD

Grupos

G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G5 - Materiais Biomiméticos, Biológicos e Vivos

Projectos

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

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)

agradecimentos

The work was funded by projects A-MoVeR - Mobilizing Agenda for the Development of Products & Systems toward an Intelligent and Green Mobility, operation n.degrees 02/C05-i01.01/2022.PC646908627-00000069, approved under the terms of the call n.degrees 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 from 2021 to 2026. This work was also developed within the scope of the projects SOLPOWINS - Solar-Powered Smart Windows for Sustainable Buildings (PTDC/CTM-REF/4304/2020), CQ-VR (UIDB/0616/2020 and UIDP/0616/2020) CICECO-Aveiro Institute of Materials (UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020) and Instituto de Telecomunicacoes (UIDB/50008/2020 and UIDP/50008/2020), financed by national funds through the FCT/MEC (PIDDAC), and when appropriate co-financed by FEDER under the PT2020 Partnership through European Regional Development Fund (ERDF) in the frame of Operational Competitiveness and Internationalization Programme (POCI), and developed within the scope of the project Fiber Materials and Environmental Technologies (FibEnTech-UBI) (UIDB/00195/2020 and https://doi.org/10.54499/UIDB/00195/2020), financed by national funds through the FCT/MCTES (PIDDAC). P. J. Nunes acknowledges CQ-VR/FCT for a grant (https://doi.org/10.54499/UI/BD/151084/2021). R.F.P. Pereira acknowledge FCT for CQ-UM base and programmatic projects (UIDB/00686/2020 and UIDP/00686/2020) and FCT-UMinho for the contract in the scope of Decreto-Lei 57/2016 (https://doi.org/10.54499/DL57/2016/CP1377/CT0050). S. C. Nunes acknowledges FCT for Assistant Research contract (https://doi.org/10.54499/2020.00805.CEECIND/CP1625/CT0001) in the scope of Scientific Employment Stimulus. P. J. Nunes acknowledges CQ-VR/ FCT for a grant (https://doi.org/10.54499/UI/BD/151084/2021). M. Fernandes acknowledges FCT-UTAD for the contract in the scope of Decreto-Lei 57/2016 - Lei 57/2017 (https://doi.org/10.54499/DL57/2016/CP1378/CT0001). S.F.H. Correia also thanks FCT (2022.03740.CEECIND/CP1716/CT0006).