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. 2019 Sep 3;19(17):3801. doi: 10.3390/s19173801

Figure 1.

Figure 1

(a) TEM image of the CDs. The inset in (a) is the particle size distribution histogram. (b) FTIR image of the CDs. (c) XPS survey spectrum of the CDs. (df) High-resolution XPS spectra of C1s, N1s, and O1s, respectively.