fig1

Figure 1. Sample preparation and structural characterizations. (A) Schematic diagram of the synthesis process for the NFP/C-HT sample; (B) XRD patterns of NFP/C, NFP/C-T_0.01, NFP/C-H, and NFP/C-HT_0.01 samples; (C) schematic of the maricite NFP crystal; (D) crystal structure diagram sectioned along the (111) plane; (E) ICP results for the NFP/C-T_0.01, NFP/C-H, and NFP/C-HT_0.01 samples; (F-H) full XPS spectra of samples NFP/C-T_0.01, NFP/C-H, and NFP/C-HT_0.01; and (I-K) Fe 2p XPS spectra of NFP/C-T_0.01, NFP/C-H, and NFP/C-HT_0.01.