Figure shows the number of publications in the from 2012. The number of publications in the journals and patents shows a steady increase over the years, demonstrating the continuous rising interest in this field. The huge difference between journal publications and the patents is an indication that research in this area of sustainable photocatalysts has still not reached the point of commercialization. As expected, the 15 topmost cited documents were reviews of the existing literature and they cover various aspects such as co-catalysts for photocatalysts, catalytic water treatment, hydrogen evolution, silver nanoparticles, Cu based nanoparticles, noble-metal free nanoparticles, semiconductors for photocatalytic water splitting, transition-metal based cocatalysts for photocatalytic water splitting, carbon nitride photocatalysts, MXene photocatalysts, nano and microstructured catalysts, non-noble metal plasmonic photocatalysts, 100 and single-atom catalysts on 2D nanomaterials. 6 out of the top 25 most cited photocatalyst related documents were about graphitic carbon nitride, highlighting the interest and the potential of this specific photocatalyst.