Just like a melon: Carbon nitride photocatalysts (see formula) structurally akin to poly(aminoimino)heptazine (Liebig′s melon) can be prepared by direct copolymerization of dicyandiamide with barbituric acid (BA). The picture shows how increasing the amount of BA in the copolymerization mixture (arrows) extends the optical absorption of the products further into the visible region, as is favorable for solar-energy applications. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.