Quantum dots being zero dimensional and much smaller in size have special properties and density of states that can be exploited for various commercial applications relative to bulk counterparts. Specific characteristics of semiconductor metal oxides are tunable by controlling size, composition, shape and combination with metal or non-metal component. Current study focus the facile fabrication of SnO2 qunatum dots decorated on 2-D material g-C3N4. Using a simple route SnO2/g-C3N4 nanonybrids have been prepared in pure phase with size of SnO2 are found in Quantum dots (QDs) range (2–10 nm) and applied to target the enhanced photocatalytic activity. The structural and morphological features of SnO2/g-C3N4 nanohybrids were successfully conducted by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The photocatalytic performance of the SnO2/g-C3N4 nanohybrids was evaluated for the degradation of Rhodamine-B (RhB) solution, and an enhanced activity is observed attesting synergetic effect between SnO2 QDs and exfoliated g-C3N4 layers. It is found that the ratio of SnO2 to g-C3N4 in the hybrids critically affects the photocatalytic activity, with ratio 1:2 showing best performance. The present study offers simple and facile method to highlight the promising contribution of SnO2/g-C3N4 hybrid in eliminating waste water organic contaminants and environmental issues.