Conductive polymers perform as a new class of very active photocatalysts under visible light. Among them, polypyrrole (PPy) is one of the most promising conjugated polymers with a wide range of applications. PPy and doped PPy were synthesized on glass plate in thin film form by a facile simple successive ionic layer adsorption and reaction method. Polypyrrole is doped with dodecyl benzene sulphonic acid, toluene sulphonic acid, hydrochloric acid, sodium iodide (NaI), citric acid (commercial) and citric acid (lemon). The synthesized thin film was well characterized using UV-visible spectrophotometer, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and photoluminescence (PL). The electrical conductivity was measured by Hall effect measurements. Among various organic and inorganic acid dopants, NaI-doped PPy thin film exhibited narrow band gap and has excellent ability to absorb light in red region of the spectrum. NaI-doped PPy thin film showed higher conductivity when compared to other dopants. A lower PL intensity of NaI-PPy thin film indicates higher electron-hole pair separation efficiency. The photocatalytic activities of PPy thin film and NaI-doped PPy thin film on rhodamine 6G dye under visible light were systematically investigated. NaI-doped PPy thin film had better degradation efficiency than PPy due to its higher electron-hole pair separation efficiency.