An eco-friendly and bio-surfactant assisted room temperature synthesis has been proposed for preparation of Magnetic retrievable Fe3O4@rGO nanocomposite in Averrhoa carambola leaf extract towards 2-nitrophenol reduction and TCH degradation under visible light illumination. The role of bio-molecules that are present in leaf extract is quite crucial in the process of tuning the morphology and opto-electronic features of Fe3O4 nano-particles. Additionally, the insitu conversion of GO to rGO and preparation of Fe3O4 from Fe+2 and Fe+3 metal precursors leads to formation Fe3O4@rGO nanocomposite. rGO sheets play the key role in successful transfer and separation of photoexcited charge carrier resulting in better catalytic activity compared to neat Fe3O4. Among the designed nanocomposites 3 wt% loaded rGO i.e. FG-3 shows the best result with 95.85% 20 ppm 2 Nitrophenol reductions and 94.09% 10 ppm TCH degradation under visible light irradiation for 30 and 60 mins respectively. The observed high photocatalytic performance of FG-3 is attributed to synergetic chemistry operating between rGO and Fe3O4 components that causes effective separation and channelization of excitons to active sites and also due to increase in surface area of composite material. The above stated separation efficiency and surface area expansion is well supported by PL/Impedance measurements and BET analysis respectively. Further the phase purity, uniform distribution of nanoparticles and reduction of GO to rGO is well characterised through XRD, FESEM/TEM and Raman/FTIR analysis respectively.