We integrated ZnO with g-C3N4 nanostructures via successful core-shell formation using single step simple sintering process for photocatalysis application. Analytical tools show that the g-C3N4 shell with an average thickness of 3 nm has been coated onto surface of ZnO nanoparticles. Additionally, few ZnO particles are sporadically distributed on g-C3N4 sheets forming their nanocomposites. Further, these core -shell nanocomposites are used as photocatalysts for the degradation of Rhodamine B (RhB) under visible irradiation. As a result of photocatalysis measurements, it was found that 0.75 wt% zinc source with g-C3N4 exhibited almost two times high kinetic rate constant (k = 6.87 x 10(-3) min(-1)) as compared with that of pure g-C3N4 (k = 3.38 x 10(-3) min(-1)) and ZnO (k = 1.03 x 10(-3) min(-1)) nanostructures. This enhanced photocatalytic performance of coreeshell nanocomposites was aroused from effective interfacial charge separation and transportation, resulted into rapid degradation of RhB molecules. Moreover, increased optical absorption in visible region of spectrum revealed the large number of generation of charge carriers. Fabricated ZnO/g-C3N4 core-shell nanocomposites are also stable upto four cycles, indicating its good stability. Therefore, present coreeshell nanocomposites can be applied to water purification devices under visible irradiation. (C) 2015 Elsevier B.V. All rights reserved.