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

Abstract

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.