Naphthalene Monoanhydride and Perylene Composites for Efficient Photocatalytic Hydrogen Evolution and Metal-Free Heterogeneous Oxidative Amidation.

This study explores the synthesis of two visible light active organic chromophore-based composites using naphthalene monoanhydride () and 1,7-dibromoperylene monoanhydride diester (). These chromophores feature favorable optical and electronic properties and polyaromatic skeletons with anhydride functionalities that facilitate π-π interactions between the chromophore and polymeric carbon nitride () or covalent connections of chromophores with NH groups of . Accordingly, heterogeneous chromophore- composite photocatalysts namely, and were prepared by adopting calcination (c) and composites and were prepared by physical adsorption (a) methods. prepared and composites exhibited H evolution rates (HER) of 1069 and 705 μmol h g, respectively, which are significantly higher than ex situ and composites with HER of 465 and 252 μmol h g, respectively. These rates are 10, 7, 4.8, and 2.5 times higher than the bulk-, indicating the potential of these composites for efficient photocatalytic H evolution. Surface area normalized HER enhancements were 3.8, 5.3, 6.6, and 4.2 times higher for , , , and respectively compared to bulk-. These composite photocatalysts exhibited excellent stabilities under prolonged photoirradiation, with H evolution consistently increasing with the light exposure time. Additionally, these metal-free heterogeneous composites demonstrated efficient photocatalytic activities towards oxidative amidation of aromatic aldehydes, with up to 80% product yields, establishing the prospects of combining homogeneous and heterogeneous entities in a metal-free active material in solar energy harvesting.