Role of alkali-cyano group interaction in g-C3N4 based catalysts for hydrogen photo-production

• Published in: Catalysis today Vol. 394-396; pp. 25 - 33
• Main Authors: Caudillo-Flores, Uriel, Ares-Dorado, Alejandro, Alonso-Nuñez, Gabriel, Tudela, David, Fernández-García, Marcos, Kubacka, Anna
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: Alkali; Carbon nitride; Hydrogen; Photo-catalysis; Sunlight; Sunlight; Alkali; Photo-catalysis; Hydrogen; Carbon nitride
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2021.06.028

Carbon nitride based materials incorporating K and Na alkali ions were used as support(s) to deposit platinum. The systems were tested in the photo-production of hydrogen using methanol as a sacrificial molecule. Tests under UV and sunlight-type illumination conditions showed an important promoting effect of the alkali ions irrespective of the illumination source characteristics. The measurement of the quantum efficiency was used to quantitatively assess the performance of the catalysts. Outstanding results were obtained, particularly under sunlight illumination. A complete characterization study of the materials was carried out to establish a structure-activity link. This link correlates catalytic activity with the capture of charge carrier species by surface cyano groups directly associated with the presence of alkali ions at the carbon nitride component. [Display omitted] •Modification of g-C3N4 by alkali incorporation and Pt deposition.•Analysis of photoactivity by means of the quantum efficiency parameter.•Alkali presence increases activity under all illumination conditions.•Interplay between cyano groups and alkali ions controls activity.