首页|Tuning photodegradation performance using carbon quantum dots and niobium pentoxide

Tuning photodegradation performance using carbon quantum dots and niobium pentoxide

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Carbon quantum dots(CQD)were employed as dopants to enhance the photocatalytic efficiency of Nb2O5 by decreasing the bandgap energy and prolonging the lifetime of the photogenerated exciton by in-creasing conductivity.X-ray diffraction(XRD),N2 porosimetry,scanning electron microscopy(SEM),elec-trochemical impedance spectroscopy(EIS),photoacoustic spectroscopy(PAS),X-ray photoelectron spec-troscopy(XPS),Dynamic Light Scattering(DLS),zeta potential,and atomic force microscopy(AFM)were used to characterize the synthesized nanostructures.The residues from acerola processing were converted into CQD with an average size of 2.56 nm,as confirmed by AFM and the high fluorescence quantum yield of 43.32%.N2 physisorption results showed that the CQD were deposited on the surface of Nb2O5,re-ducing the specific surface area(SBET)from 122±2.0 to 29±1.3 m2 g-1.The photocatalytic performance of CQD/Nb2O5 was superior to that of the control materials under UV-vis light irradiation,as there was a decrease in the bandgap energy(Eg)from 2.78 to 1.93 eV.This decrease in Eg led to a significant increase in the apparent rate constant(kapp)of the MG dye from 1.90 ×10-3 s-1 to 42.2 ×10-3 s-1,demonstrating that the presence of CQD can effectively separate the photogenerated charge carriers,as it was observed from the increase in conductivity showed by Nyquist diagram.

Acerola bagasseMalachite greenCarbon dotsPhotocatalystChemical kinetics

Lucas Spessato、Lucas H.S.Crespo、Marcela C.Silva、Mariana S.Gibin、Francielle Sato、Manuel E.G.Winkler、Vitor C.Almeida

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Department of Chemistry,State University of Maringá,Av.Colombo 5790,Maringá,Paraná,Brazil

Department of Physics,State University of Maringá,Av.Colombo 5790,Maringá,Paraná,Brazil

Institute of Chemistry,University of Campinas,Campinas,CEP:13083-970,SP,Brazil

Conselho Nacional de Desenvolvimento Cientí-fico e Tecnológico(CNPq)CNPqCNPqFunda??o Araucária

168182/2022-0403525/2023-3308314/2022-0JDT202227100005

2024

材料科学技术(英文版)
中国金属学会 中国材料研究学会 中国科学院金属研究所

材料科学技术(英文版)

CSTPCD
影响因子:0.657
ISSN:1005-0302
年,卷(期):2024.191(24)