2.4. C-Dots Quantum Yield Determination

The quantum yield was calculated based on the following equation (the relative method):

where Φ_s is the quantum yield of the standard sample; I_S and I are the integrated area under the emission peaks of the standard and unknown samples, respectively; A_S and A are the absorbance of the excitation wavelengths of the standard and unknown samples, respectively; n_S and n are the refractive indices of the standard and unknown samples, respectively; and D/D_S is the dilution ratio if the samples are diluted during the measurement of fluorescence emission. In this experiment, UV-Vis absorption and the fluorescence emission spectra of C-dots were recorded using deionized water as the solvent. Quinine sulfate in 0.1 M H₂SO₄ (quantum yield: 0.54) was used as the standard for quantum yield calculation. The refractive index of water is 1.333 and for 0.1 M H₂SO₄, it is 1.346.