Mn (IV) oxide/Mn (IV) sulfide/poly-2-amino-1-mercaptobenzene for green hydrogen generation

A manganese (IV) oxide (MnO₂)–manganese (IV) sulfide (MnS₂)/poly-2-amino-1-mercaptobenzene (P2AMB) nanocomposite is prepared through a polymerization reaction (oxidation) and is utilized as a highly photo-electrocatalytic material for green hydrogen generation from sewage water. The manganese (IV) oxide–manganese (IV) sulfide/P2AMB nanocomposite demonstrates remarkable optical properties, characterized by a band gap of 1.81 eV. To promote the water-splitting reaction by the synthesized manganese (IV) oxide–manganese (IV) sulfide/P2AMB nanocomposite photoelectrode, sewage water is utilized as a sacrificial agent to facilitate effectively the generation of hydrogen gas through the evaluation of the current (J _ph). At −0.9 V, the J _ph and J _o values are determined to be −0.33 and −0.2 mA/cm², respectively. Notably, an optimum J _ph value of −0.26 mA/cm² is observed for incident photons at 340 nm, indicating that light with higher frequency and energy leads to the generation of more electrons from the manganese (IV) oxide–manganese (IV) sulfide/P2AMB nanocomposite and subsequent hydrogen production. Conversely, the lowest J _ph value of −0.21 mA/cm² is obtained at 730 nm, suggesting the influence of infrared waves on the photoelectrode due to the small band gap (1.86 eV) of the materials, as calculated in a previous analysis. This study represents an initial step toward the conversion of wastewater into hydrogen gas, which can serve as a sustainable fuel source for various industrial applications.