Table 4. DFT Calculation Results for the Adsorption Energies (in eV) of Neutral and Anionic Forms of PFOA and PFBS and Water onto Graphene Structures with Various Functional Groups.

test condition	PFBS	PFOA	anionic PFBS	anionic PFOA	H2O
PAC with C=O, −COOH, and −OH (5% oxygen)	–0.13013	–0.1935	–1.2012	–1.5013	–1.6532
PAC with COOH (2% oxygen)	–0.2122	–0.3651	–1.4543	–1.6798	–0.4321
PAC with C=O (2% oxygen)	–0.23673	–0.26543	–1.3211	–1.5244	–0.38854
PAC with C–OH (2% oxygen)	–0.3435	–0.4026	–1.4843	–1.6732	–0.35858
PAC with COOH and NH2 (2% oxygen, 0.5%N)	–0.53232	–0.58244	–1.6211	–1.8912	–0.82123
PAC with C=O and NH2 (2% oxygen, 0.5%N)	–0.36854	–0.4269	–1.4343	–1.7456	–0.83122
PAC with C–OH and NH2 (2% oxygen, 0.5%N)	–0.49763	–0.51749	–1.5621	–1.8134	–0.82654
PAC with COOH and N (2% oxygen, 0.5%N)	–0.58432	–0.61224	–1.6234	–1.9055	–0.92321
PAC with C=O and N (2% oxygen, 0.5%N)	–0.39462	–0.41237	–1.4743	–1.8122	–0.90356
PAC with C–OH and N (2% oxygen, 0.5%N)	–0.52931	–0.54231	–1.5839	–1.8542	–0.88834