Increasing the Visible Light Absorption of Graphitic Carbon Nitride (Melon) Photocatalysts by Homogeneous Self‐Modification with Nitrogen Vacancies

Abstract

A novel reduced melon photocatalyst with a bandgap of 2.03 eV developed here has a widened visible light absorption range and suppressed radiative recombination of photo-excited charge carriers due to the homogeneous self-modification with nitrogen vacancies. As a consequence, the reduced melon shows a much superior photocatalytic activity compared to the pristine melon in generating •OH radicals and degrading the organic pollutant Rhodamine B.

Condensed and low-defected graphitic carbon nitride with enhanced photocatalytic hydrogen evolution under visible light irradiation

“…The contribution at 400.4 eV corresponded to bridging nitrogen atoms N-(C)3 in heptazine unit (N 3C ). 13 These assignments of C1s and N1s agree well with the g-C 3 N 4 reported previously [24]. The surface atomic ratio of carbon to nitrogen was 0.76 in the pristine CNn and 0.73 in the low-defected CNa.…”

Macroscopic 3D Porous Graphitic Carbon Nitride Monolith for Enhanced Photocatalytic Hydrogen Evolution

“…[ 1e , 3, 4 ] Nevertheless, it still suffers from some drawbacks, such as small specifi c surface area (SSA), low visible light utilization effi ciency, and rapid recombination of photogenerated carriers. [ 3,5 ] For these reasons, many impressive results have been obtained by modifying g-CN by coupling with other materials such as carbon dots, [ 1e ] graphene, [ 6 ] hydrogenase, [ 7 ] semiconductors, [ 8 ] aromatic compounds, [ 9 ] and doping with heteroatoms such as P, [ 10 ] F, [ 11 ] O, [ 12 ] B, [ 11,13 ] I, [ 5a ] S, [ 14 ] and Fe, [ 15 ] and introducing nitrogen vacancies [ 16 ] to overcome the aforementioned problems. Besides, a variety of forms of nanostructured g-CN including nanosheets, [ 17 ] Direct evidence for the formation of g-CN is obtained using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry (TG), and X-ray photoelectron spectroscopy (XPS) analysis.…”

Holey Graphitic Carbon Nitride Nanosheets with Carbon Vacancies for Highly Improved Photocatalytic Hydrogen Production

“…One way is optimizing the electron and bandgap structures by introducing functional groups, [ 4 ] doping with heteroatoms, [ 5 ] modifying with nitrogen vacancies, [ 6 ] or constructing heterojunctions with other semiconductor materials. [ 7 ] Another approach is the development of various GCN nanostructures with optimized physicochemistry and optical properties, including nanoparticles, [ 8 ] nanosheets, [ 1g , 9 ] nanorods, [ 10 ] nanoribbons, [ 11 ] nanotubes, [ 12 ] nanospheres, [ 1e , 13 ] "seaweed," [ 14 ] etc.…”