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Brønsted base site engineering of graphitic carbon nitride for enhanced photocatalytic activity.
- Source :
- Journal of Materials Chemistry A; 9/28/2017, Vol. 5 Issue 36, p19227-19236, 10p
- Publication Year :
- 2017
-
Abstract
- Graphitic carbon nitride (g-C<subscript>3</subscript>N<subscript>4</subscript>) is a promising two-dimensional polymeric photocatalyst in the field of solar energy conversion. In the past few years many modifications of g-C<subscript>3</subscript>N<subscript>4</subscript> have been studied extensively; however, the difficulty in obtaining detailed structural information both on its intrinsic covalent interactions and surrounding bonding environments largely restricts the rational design and development of inherent structure-controlled g-C<subscript>3</subscript>N<subscript>4</subscript> based photocatalysts and fundamental understanding of their mechanistic operations. Herein, we demonstrate a high-pressure hydrogenation treatment method for g-C<subscript>3</subscript>N<subscript>4</subscript> and introduce 1D <superscript>13</superscript>C and <superscript>15</superscript>N and 2D <superscript>15</superscript>N Radio Frequency-driven Dipolar Recoupling (RFDR) solid-state nuclear magnetic resonance spectroscopy for identifying the structural information and surrounding hydrogen-bonding environment of treated g-C<subscript>3</subscript>N<subscript>4</subscript> samples. The surface Brønsted base sites of g-C<subscript>3</subscript>N<subscript>4</subscript> samples can be tuned systematically through changing the treatment conditions. We find that the terminal isolated –NH<subscript>2</subscript> and the hydrogenated nitrogen species in treated g-C<subscript>3</subscript>N<subscript>4</subscript> samples seem to be the origin of their improved activities for photocatalytic hydrogen evolution and favor the enhancement of light harvesting and carrier transport. The as-prepared HCN<subscript>400-4-2</subscript> sample treated at a pressure of 4 MPa and a temperature of 400 °C for 2 h in a hydrogen atmosphere displays the highest H<subscript>2</subscript> evolution reaction (HER) activity, which is over 26 times higher than that of pristine g-C<subscript>3</subscript>N<subscript>4</subscript>. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20507488
- Volume :
- 5
- Issue :
- 36
- Database :
- Complementary Index
- Journal :
- Journal of Materials Chemistry A
- Publication Type :
- Academic Journal
- Accession number :
- 125231717
- Full Text :
- https://doi.org/10.1039/c7ta06602c