Oxygen functional groups in graphitic carbon nitride for enhanced photocatalysis

Synthesis of g‐C3N4 Nanosheets by Using a Highly Condensed Lamellar Crystalline Melamine–Cyanuric Acid Supramolecular Complex for Enhanced Solar Hydrogen Generation

“…The bending of CN‐A nanosheets also creates a crumpled structure, leading to a much higher specific area. Importantly, the presence of C=O groups induces an upshift of the CB edge of CN‐A, which could thermodynamically promote the hydrogen evolution reaction . The subsequent calcination step in air produces more extraordinary features in CN‐AA.…”

“…Importantly,t he presence of C=Og roups induces an upshift of the CB edge of CN-A, which could thermodynamically promotet he hydrogen evolutionr eaction. [29] The subsequent calcination step in air produces more extraordinary features in CN-AA.S everalc arbon species in the CN-A framework were removed owing to the reaction with oxygen in air,c reatinga large number of in-plane nanoholes. The introduction of these nanoholes increased the specific surface area of CN-AA up to 270 m 2 g À1 ,w hich is one of the highest specific surfacea reas observed in carbon nitride materials.…”

Heteroatom‐Doped Carbonaceous Photocatalysts for Solar Fuel Production and Environmental Remediation

“…N/O‐doped carbonaceous photocatalysts (Table ) are prepared through thermal condensation of N ‐containing precursor in the presence of H 2 O 2 , the chemical oxidation post‐treatment of as‐prepared g‐C 3 N 4 by H 2 O 2 , or mixed acids (HNO 3 /H 2 SO 4 ), the photo Fenton reaction of g‐C 3 N 4 nanosheets by UV irradiation in the presence of Fe 2+ /Fe 3+ and H 2 O 2 , the heating post‐treatment of GO in NH 3 , or through a slicating approach of GO with 2D carbon nitride nanodots. Generally, the co‐doped carbonaceous photocatalysts show higher S BET , promoted light absorption, and prolonged lifetime of photogenerated electron‐hole pairs in different degrees, which are dependent on the doping method and doping level.…”

“…From Table , O, N ‐codoped carbonaceous photocatalysts have been used in hydrogen generation from water splitting, and the environmental purification by degradation of organic pollutants like RhB, MO, MB, phenol . Through O‐doping with appropriate content, distribution, and chemical state, the porous g‐C 3 N 4 photocatalysts with higher S BET , and the promoted light absorption as well as enhanced separation, transfer and recombination of photogenerated charge carriers can be ontained, which endows them with remarkably improved photocatalytic properties in contrast to pristine g‐C 3 N 4 .…”

“…N/O-doped carbonaceousphotocatalysts ( Table 7) are prepared through thermalc ondensation of N-containing precursor in the presence of H 2 O 2 , [264] the chemical oxidation post-treatment of as-prepared g-C 3 N 4 by H 2 O 2 , [265,266] or mixed acids (HNO 3 /H 2 SO 4 ), [267] the photo Fentonr eactiono fg -C 3 N 4 nanosheets by UV irradiation in the presence of Fe 2 + /Fe 3 + and H 2 O 2 , [177] the heating post-treatment of GO in NH 3 , [268] or throughas licatinga pproach [201] of GO with 2D carbon nitride nanodots.G enerally,t he co-doped carbonaceousp hotocata- ( Figure 22 b, c), shows 4.4 times higher S BET with 0.09 cm 3 g À1 of V total and 20.7 nm of pore size, narrower band gap by 0.08 eV,m uch lower PL intensity and significantly promoted conductivity than pristine g-C 3 N 4 (Figure 22 d, e). By increasing Oc ontent from 1.5 to 3.0 at %, the as-preparedM CN-2 features similar morphology, S BET ,a nd V total to MCN-1, but it exhibits 39.3 nm of larger pore size and the 150 nm of larger cavity size.…”