Table 6.

A summary of syntheses and FL properties of CDs with red/NIR

	Carbon resource	N resource or others	Synthetic approach	Excitation wavelength (nm)	Emission wavelength (nm)	Mechanism	References
Top-Down	Tire soot	Nitric acid	Oxidation	430-710	500-800	Surface defects	218
	Carbon fibers	Nitric acid	Oxidation	Excitation‐independent	430-610	Size and degree of surface oxidation	219
	Coal pitch powder	Formic acid and H2O2	Oxidation	Excitation‐independent	630	Intermolecular forces	220
	Graphite	K2S2O8 solution	Electrochemical	Excitation‐independent	610	Conjugated sp2	221
	Alcohols		Electrochemical	390-410	485-505	Conjugated sp2	222
	Toluene		Laser ablation	Excitation‐independent	600	Quantum confinement effect	223
	Graphite Powders		Laser ablation	400	650	Size	224
	Graphite	NH2	Ultrasonic	543	580-750	Surface defects	225
Bottom-Up	P-phenylenediamine	Phosphorus acid	Hydrothermally	Excitation‐independent	622	Surface Molecular Fluorescence	226
	CA	Neutral red	Hydrothermally	Excitation‐independent	632	Compositions and structures	163
	P-phenylenediamine	Ni2+	Hydrothermally	Excitation‐independent	535-700	Size and degree of surface oxidation	50
	Trimesic acid	4-aminoacetanilide	Hydrothermally	520	582	Size and emissive trap sites	227
	2,5-diaminobenzenesulfonic acid		Hydrothermally	Excitation‐independent	593	Size and surface defects	228
	FA	Phenylenediamine isomers	Hydrothermally	365	530, 429, and 612	Surface state	229
	3-aminobenzeneboronic acid	2,5-diaminobenzenesulfonic acid	Hydrothermally	520	605	Size and surface state	230
	Cresyl violet	Boric acid	Hydrothermally	520	616	Surface state	139
	CA	Ethanediamine and lignin	Hydrothermally	375-460	454-535	Aromatic π systems and n - p* transitions	231
	O‐phenylenediamine	Dopamine and HNO3	Hydrothermally	Excitation‐independent	630	Conjugated aromatic π systems and hydrogen bonds	226
	P‐phenylenediamine	O‐phenylenediamine and dopamine	Hydrothermally	573	640	Conjugated sp2	232
	CA	Urea and N,N-dimethylformamide	Hydrothermally	553	606	n-π* transition of heteroatomic	233
	P-phenylenediamine	Urea	Hydrothermally	Excitation‐independent	440-625	Degree of oxidation	234
	CA	5-amino-1,10-phenanthroline	Hydrothermally	560	630	Phenanthroline part	235
	CA	1,4,5,8-tetraminoanthraquinone	Hydrothermally	600	700	C=C and C=N	236
	L‐methionine	urea	Hydrothermally	550	625	Conjugated sp2	237
	Selenourea	O-phenylenediamine and hydrochloric acid	Hydrothermally	Excitation‐independent	625 and 679	Low-energy surface state	238
	CA	Ethanediamine and meso-tetra (4-carboxyphenyl) porphin	Hydrothermally	Excitation‐independent	645	The surface structures and states	239
	1,3-dihydroxynaphthalene	KIO4	Solvothermal	530	628	Conjugated sp2	240
	Perylene	HNO3 and NaOH	Solvothermal	560	610	Surface electronic state induced by the alkali	241
	Taxus leaves	Acetone	Solvothermal	413	722	Excited state relaxation channels and single PL center	219
	4-aminophenol	KIO4 and ethanol	Solvothermal	540	620	C=C and C=N	242
	CA	PEI and formamide	Solvothermal	550	640	Surface state	54
	Alizarin	Urea	Microwave-assisted	Excitation‐independent	605	C=C and C=N	243
	Glutathione	Formamide	Microwave-assisted	420	683	Surface molecular state	244