Electrocarboxylation of benzophenone was studied on silver (Ag) nanoparticles modified boron doped diamond (BDD) electrode in N,N-dimethylformamide/tetrabutylammonium tetrafluoroborate (DMF/TBABF(4)) medium. Voltammetric analysis reveals that Ag/BDD electrode shows a positive shift of peak potential (100 mV) when compared to the bare BDD on the electro reduction of benzophenone, indicating catalytic influence of Ag nanoclusters. Potentiostatic electrolysis experiment exhibits higher yield of 2-hydroxy-2,2'-diphenyl acetic acid (benzilic acid) on the Ag/BDD than that of Ag and the BDD. Efficient generation of highly stable ketyl radicals on the Ag/BDD was confirmed by electron spin resonance (ESR) spectroscopy. (C) 2015 Published by Elsevier B.V.