Abstract
Three nanomaterials based on polyaniline (PANI) are prepared on indium tin oxide (ITO) and applied as electrodes for H-2 generation due to the water-splitting process. PANI/ITO films are prepared using oxidation polymerization method at 25 degrees C, then coated with Au nanoparticles with different thicknesses (sputter time from 1 to 2 min). The three prepared electrodes; PANI/ITO (Electrode (0), 1-min-Au/PANI/ITO (Electrode (I)), and 2-min-Au/PANI/ITO (Electrode (II)) are compared for H-2 generation from H2O. Scanning electron microscope, X-ray diffraction, UV-Vis spectrophotometer, and Fourier-transform infrared spectroscopy analyses have been carried out, in which the average PANI crystal size was 20 nm. Moreover, the bandgaps were determined, in which 2-min-Au/PANI/ITO has the optimum bandgap of 2.25 eV. The characteristic behavior of the H-2 generation took place depending on the current density (J(ph)) value by using J(ph)-V and J(ph)-time study. Also, the incident photon-to-current conversion efficiency (IPCE) and the applied bias photon-to-current efficiency (ABPE) were calculated for the Electrode (II) at 25 degrees C. The optimum IPCE and ABPE efficiency were 18.7 and 0.99%, respectively, at 390 nm. By increasing the temperature to 70 degrees C, the IPCE efficiency increases to about 37%. Finally, activation energy (E-a), enthalpy (Delta H*), and entropy (Delta S*) were determined, in which the values were 24.32 kJ mol(-1), 10.90 kJ mol(-1), and 74.99 J K-1 mol(-1), respectively. (c) 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019