Poly(m‐toluidine)/rolled graphene oxide nanocomposite photocathode for hydrogen generation from wastewater.

Summary: This study provides hydrogen gas fuel as a renewable energy source. The production of H2 was carried out through the photocatalytic decomposition of sewage water using highly efficient poly(m‐toluidine) (PMT)/rolled graphene oxide (roll‐GO) as photoelectrode. The preparation of PMT thin film was carried out on glass using the in situ electropolymerization reaction from an acid medium. Then, the roll‐GO was deposited on this thin film using the casting method from the GO solution. The full characteristic analyses Fourier‐transform infrared, X‐ray diffraction, scanning electron microscope, transmitted electron microscope, and UV‐Vis spectroscopy confirmed the chemical structural, morphological, and optical properties of the prepared nanomaterials. The morphology characteristic confirmed the formation of nanopores PMT, rolled GO, and rolled porous nanocomposite. The bandgap values for PMT, roll‐GO, and PMT/roll‐GO nanomaterials were 2.38, 2.67, and 1.65 eV, respectively. The hydrogen generation was carried out through the photoelectrode glass/PMT/roll‐GO with a current density (Jph) value of 0.08 mA.cm−2 at +1 V, with hydrogen moles of 10 μmole/h.cm−2. The Jph values changed from 0.078 to 0.053 mA.cm−2 with changing the monochromatic light wavelengths from 390 to 636 nm, respectively. Moreover, the Jph values increased from 0.078 to 0.295 mA.cm−2 which is followed by an increase in the temperature from 20°C to 60°C, respectively. The thermodynamic parameters were calculated, in which the Ea, ΔS*, and ΔH* values were 27.3 kJ/mol, 188.3 J/mol.K, and 24.7 kJ/mol, respectively. The wettability was studied for the PMT and PMT/roll‐GO films, in which the contact angles were changed from 92° to 41°, respectively. Finally, the mechanism was used for the explanation of the water‐splitting reaction using the PMT/roll‐GO photoelectrode under the light. [ABSTRACT FROM AUTHOR]