Tricobalt tetraoxide (Co3O4) thinfilm was successfully deposited for the first time by a novel sparking method through a two-step process, which includes cobalt nitrate deposition and subsequent thermal treatment at 300 °C. The formation mechanism of Co3O4 deposition by sparking process from highly pure cobalt wire is elucidated in detail. Deposited Co3O4 thinfilms under different spark repetition rates were intensely characterized and employed as an effective photocatalyst for degradation of organic dye. Notably, the maximum degradation of organic dye was observed for the catalytic thinfilm deposited at low repetition rate owing to its low band gap and porous morphology with smaller size grains, which may lead to the contribution of more charge carriers in the photocatalytic reaction.