Hollow porous prismatic graphitic carbon nitride with nitrogen vacancies and oxygen doping: a high-performance visible light-driven catalyst for nitrogen fixation

Abstract

Hollow porous prismatic graphitic carbon nitride with nitrogen vacancies and oxygen doping was successfully constructed via a facile two-step strategy of a low-temperature hydrothermal method followed by a subsequent calcination process.

Recent advances in photocatalytic nitrogen fixation: from active sites to ammonia quantification methods

“…Recent research, hollow porous prismatic graphitic carbon nitride with nitrogen vacancies and oxygen doping was fabricated from dicyandiamidine with a facile two-step strategy of low-temperature hydrothermal method and calcination process. 87 In this work, the obtained catalyst (Nv&Od-CN) is hollow columnar and loose porous structure, which fully exposed the nitrogen vacancy as the active site with a yield of up to 118.8 mg L À1 h À1 g cat À1 . Before that, nitrogen vacancy and sulfur co-doped g-C 3 N 4 , 88 nitrogen vacancy and phosphorus co-doped g-C 3 N 4 were also reported.…”

Graphitic carbon nitride nanotubes: a new material for emerging applications

“…126 Based on a combination of FTIR, XPS, and solid-state NMR results, the authors suggested a feasible mechanism of this process, including (i) the cyclization of DCDA into tautomerized CA with the subtraction of ammonia and guanidine (HN] C(NH 2 ) 2 ) molecules and (ii) the conversion of CA into melamine at the expense of ammonia released from DCDA as well as from the in situ hydrolysis of guanidine. 126 A hydrothermal treatment of melamine or DCDA in tetrachloromethane CCl 4 yields a black powdered product, which converts to a mixture of tubes and belts upon calcination. 127 The belt width ranges from 100 nm to 3 mm with a thickness of 5- The polycondensation of melamine in a CCl 4 ow was reported to result in hollow tetragonal prisms with a length of hundreds of micrometers and a wall thickness of around 50 nm.…”

“…The rate of nitrogen reduction over GCNTs reaches almost 120 mg L À1 h À1 g À1 , which is more than 20 times higher than that of bulk GCN. 126 The GCNTs produced by scrolling and modied with Rh NCs were reported as a visible-light-sensitive photocatalyst of dechlorination of mono-, di-, and tri-substituted chlorophenols into the corresponding alcohols and ketones in aqueous solutions saturated with molecular hydrogen. 134 In contrast to the more conventional photocatalytic destruction of substituted phenols proceeding through the hydroxylation, subsequent opening of the aromatic rings, and the formation of a mixture of oxycarboxylic acids, 50,51 the reported process allows the homogeneous dissociation of C-halogen bonds on the surface of Rh NCs to be achieved and coupling of Cl and phenol radicals with hydrogen atoms to form HCl and hydrogenated alcohols and ketones with a selectivity reaching 80-90%.…”

Emerging tri‐s‐triazine‐based graphitic carbon nitride: A potential signal‐transducing nanostructured material for sensor applications

“…demonstrated a simple two‐step fabrication route to produce hollow porous prismatic g‐C 3 N 4 with nitrogen vacancies and oxygen doping (N v &O d ‐CN), using dicyandiamide as the only monomer via a low‐temperature hydrothermal process followed by calcination treatment (Figure 2D). [ 55 ] During the calcination treatment, the supramolecular precursors undergo a thermal polymerization process, which results in a hollow porous prismatic morphology with nitrogen vacancies and oxygen doping. Following this approach, N v &O d ‐CN was obtained having a high specific surface area of 220.16 m 2 g −1 .…”

“…Compared with bulk g‐C 3 N 4 , the as‐synthesized N v &O d ‐CN shows a much improved photocatalytic nitrogen fixation performance, fully exposed active sites of nitrogen vacancies, more negative conduction band, a suitable visible‐light response, and the efficient separation of photogenerated electron‐hole pairs. [ 55 ]…”