We report a facile one-pot synthesis of Au/Au2S multicomponent nanoparticles supported on viologen (V) as a hybrid nanocomposite. Sodium dithionite was used as the reducing agent for both Au and V precursors and SDS as the stabilizing agent for Au nanoparticles in aqueous reaction medium. Spectroscopy, microscopy and electrochemical measurements confirm the successful composite formation. The as-prepared flower-like composite showed excellent catalytic properties towards the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The catalytic activity factor of the Au/Au2S-V hybrid was highest in comparison to those reported for polymer supported Au nanoparticle catalysts. The enhanced catalytic performance can be attributed to the strong adsorption of 4-NP molecules onto the cationic V matrix and Au2S nanoparticle surface along with effective donor-acceptor interactions between Au-Au2S nanoparticles and V facilitating the electron transfer at the hybrid interface.