Rational design of organic-inorganic heterojunction photocatalyst has become a research hotspot of recent researchers due to their abundance and cost effectivity. Herein, we present the integrated photocatalyst carbon dot (CD) decorated on g-C3N4/AgCl heterojunction synthesized by simple impregnation method. The primary confirmation for the as-prepared samples has been carried out by various characterization techniques. From the obtained results, the ternary nanocomposite demonstrated a prominent photocatalytic activity which was almost 10 and 51 fold higher than pure g-C3N4 in the degradation of organic dyes. The reasons behind the improved efficiency are (i) The introduced CD facilitates broader absorption in the visible region because of p-conjugated CDs and provide favorable electron kinetics by creating trap states at the CD/g-C3N4 interface. (ii) The AgCl acts as an electron sinker and reduce the carrier's recombination. To justify the photocatalytic activity, a possible mechanism was proposed and verified by trapping experiments. Finally, this approach could be a new one in an organic-inorganic hybrid photocatalyst for the degradation of organic dyes. (C) 2019 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.