Hydrogenated Defects in Graphitic Carbon Nitride Nanosheets for Improved Photocatalytic Hydrogen Evolution

Abstract

Delaminated carbon nitride nanosheets were prepared by high-temperature H2 treatment of bulk carbon nitride with defects being introduced during this treatment. Although the defects can act as traps for charge carriers, reducing photoluminescence lifetime, they also form highly active photocatalytic sites for hydrogen evolution. The nanostructured materials exhibit substantially enhanced photocatalytic activity due to a synergistic effect between delamination, the presence of defects, and associated band gap changes.

Coprinus comatus-derived nitrogen-containing biocarbon electrocatalyst with the addition of self-generating graphene-like support for superior oxygen reduction reaction

“…For further study, we compared the ORR catalytic property of N-BC@G-900 with other catalysts [13,14,17,21,35,36,38], as displayed in Table S1 (online). Our results are comparable with those of the best N-doped carbon catalysts reported to date in terms of E ORR , half-wave potential, average electron transfer number (n) and limited current density, but the BET surface area of the N-BC@G-900 catalyst is much lower than that of numerous nitrogen-doped carbon catalysts [16,33,34]. In fact, the major reason for the electrocatalytic activity enhancement is the density of surface active sites rather than the total surface area, although the significance of the BET specific surface area cannot be ruled out totally [31].…”

“…The XRD result directly indicates the formation of g-C 3 N 4 in the obtained carbonaceous material during the first-step carbonization process. The yielded g-C 3 N 4 acts as a self-sacrificing template to generate the N-rich graphenelike sheets during the second-step high-temperature pyrolysis process [34], which can function as an inserting agent and self-generating support in this work.…”

Pore confinement effects and stabilization of carbon nitride oligomers in macroporous silica for photocatalytic hydrogen production

“…For example, melon delamination under hydrogen at 550 o C introduces defects that increase photoactivity. [88] The implication from these literature reports is that terminal groups promote (photocatalytic) hydrogen production. For our composites 5 -7, the CN concentration renders characterization challenging.…”

Highly efficient pollutant removal of graphitic carbon nitride by the synergistic effect of adsorption and photocatalytic degradation

“…48 The absorption associated with the different nitrogen moieties identies the defect types to some degree, as well as the uncondensed amino groups. 26,49 The N-associated species were quantied using the deconvoluted N 1s spectra (Table 1). A larger value of NH x / N(-C) 3 demonstrates the smaller degree of polymerization and more uncondensed amino groups.…”

“…13,17 However, the practical applications of g-C 3 N 4 are still hindered by the several obstacles and shortcomings, especially its low specic surface area, limited active sites, poor adsorption ability, and the serious aggregation observed during a photocatalytic process, of common bulk g-C 3 N 4 prepared via the direct polycondensation of nitrogenrich precursors. 17,18 To overcome these drawbacks, many attempts, such as doping with heteroatoms, 19,20 constructing heterostructures, 21,22 fabricating copolymers, 23,24 and thermal etching, 25,26 have been dedicated towards improving the photocatalytic capability of g-C 3 N 4 . However, preparation of a highly active g-C 3 N 4 material using a facile and eco-friendly strategy is still desirable.…”