Synthesis and photo-catalytic activity of porous g-C3N4: Promotion effect of nitrogen vacancy in H2 evolution and pollutant degradation reactions

Point‐Defect Engineering: Leveraging Imperfections in Graphitic Carbon Nitride (g‐C3N4) Photocatalysts toward Artificial Photosynthesis

“…Thus, Liang et al hypothesized that the nitrogen vacancies in their sample might occur at the sp 2 bonded N (CNC) due to the decreased ratio between the peak area of sp 2 bonded N and the bridging nitrogen atoms. [226] As for non-self-doped g-C 3 N 4 , the XPS spectra for C 1s and N 1s should be identical, indicating a preserved chemical structure after doping and an [116] Copyright 2017, Elsevier B.V. HAADF-TEM images and elemental mapping of the selected red area for C, N, O, and metal dopants in d) g-C 3 N 4 , e) g-C 3 N 4 -Na, and f) g-C 3 N 4 -K. Reproduced with permission. [169] Copyright 2018, Elsevier B.V.…”

“…[224] Through this, vacancies can be identified by the Lorentzian line attributed to the unpaired electrons of sp 2 -carbon atoms in π-conjugated aromatic rings, which are weaker on the carbon-defect modified g-C 3 N 4 , [47] and inversely, stronger for the nitrogen-defect rich g-C 3 N 4 sample. [226] Apart from EPR, nuclear magnetic resonance (NMR) spectroscopy has also been used for the identification of point-defects. NMR spectroscopy is based on the interaction of radio-frequency electromagnetic radiation with the nuclei of atoms immersed in a strong magnetic field.…”

The Improvement of Photocatalysis H2 Evolution Over g-C3N4 With Na and Cyano-Group Co-modification

“…Na-CMCN sample indicated the lower PL signal in comparison to MCN sample. The decreased peak intensity was resulted from the separation of the charge carries (Yu et al, 2014; Liang et al, 2019b). Evidently, Na-CMCN exhibited better separation effect of photoinduced charge.…”

Recent advances in photodegradation of antibiotic residues in water

“…Excessive vacancies would provide too many recombination centers for photoinduced electrons and holes, whereas insufficient vacancies would fail to achieve the desired photocatalytic performance. Vacancies may be categorized into three types: 1) anion vacancies (such as sulfur [191] , [192] , [193] , [194] , [195] , halogen [196] , [197] , [198] , [199] , nitrogen [200] , [201] , [202] and oxygen vacancies (OV) [203] , [204] , [205] , [206] , [207] ), 2) cationic vacancies (such as bismuth [208] , [209] , [210] , carbon [211] and titanium vacancies [212] , [213] , [214] , [215] ), and 3) mixed vacancies, which combine anion and cation vacancies [216] , [217] . For example, mesoporous ZrO 2 containing abundant oxygen vacancies was successfully synthesized by Zhang et al .…”