Remarkable photocatalytic performances towards pollutant degradation under sunlight and enhanced electrochemical properties of TiO 2 /polymer nanohybrids.

In this work, TiO 2 -based nanocomposites containing polyaniline (PANI), poly(1-naphthylamine) (PNA), and polyindole (PIN) were synthesized by effective and simple routes and posteriorly employed as photocatalysts and supercapacitors. Characterization techniques such as XRD, FTIR, FESEM, UV, and PL were employed to investigate the structural, morphological, and optical properties of materials. XRD analysis confirmed the successful formation of TiO 2 and TiO 2 /polymer nanocomposites. PANI, PNA, and PIN polymers were well distributed on the surface of TiO 2 nanoparticles and were investigated/explored from the FESEM analysis. The visible light absorption and the recombination rate of photogenerated charge carriers were confirmed by the UV-Vis and PL analysis. The photocatalytic properties of the nanocomposites were investigated towards malachite green (MG) dye degradation under sunlight. The dye degradation efficiency followed the order TiO 2 /PNA > TiO 2 /PANI > TiO 2  > TiO 2 /PIN. The higher efficiency of TiO 2 /PNA can be associated with its smaller bandgap energy compared to the other materials. Electrochemical properties of materials were also examined by cyclic voltammetry and galvanostatic charge-discharge measurements using a three-electrode experiment setup in an aqueous electrolyte. TiO 2 /PNA nanocomposite showed higher supercapacitor behavior compared to the other materials due to higher electrical conductivity of PNA and redox potential of TiO 2 (pseudocapacitance).