Anew Synthetic Polymers Based on Polyaniline for Dual-Functional Applications: Photoelectrochemical Water Splitting...

Polysulfanilic acid has a low efficiency for the photoelectrochemical (PEC) production of H₂ from water splitting due to high recombination rate of charge and low electrical conductivity. Therefore, polyaniline was doped with polysulfanilic acid to form a copolymer and a blend to enhance its PEC heterogeneous catalytic performance. This was achieved through the improvement of visible light absorption and charge carriers' separation property. Herein, nine polymer samples of polysulfanilic acid were synthesized by oxidative polymerization. The structural, morphological, and optical properties of the synthesized polymeric materials were investigated. Interestingly, these polymer samples had multifunctional applications regarding their hydrogen generation efficiency. Photoelectrodes of different compositions from pure and blended polymers were prepared and used for the PEC solar hydrogen production from water. Different PEC parameters including the oxidant role, monochromatic illumination wavelength, and electrode reusability were optimized toward the efficient hydrogen generation. Moreover, the PEC performance was evaluated using key indicators such as photocurrent density, conversion efficiency, and the number of hydrogen moles. The number of hydrogen moles was quantitatively estimated to be 140.4, 160.2, and 300 μmol/h·g at -1 V for the polymer, copolymer, and polymer blend, respectively, in the presence of APS + FeCl₃ as an oxidant. Further, other samples of polymers showed antimicrobial properties against different species of bacteria. Hence, the present study may provide a cost-effective method to produce solar hydrogen fuel from water.