Hydrogen Generation of Cu₂O Nanoparticles/MnO-MnO₂ Nanorods Heterojunction Supported on Sonochemical-Assisted Synthesized Few-Layer Graphene in Water-Splitting Photocathode

In this study, we investigated the production of hydrogen by photochemical water splitting. A multi-shaped Cu₂O nanoparticles/MnO-MnO₂ nanorods heterojunction on a few-layer graphene-based electrode serves as the photocathode. Multi-shaped Cu₂O nanoparticles, including truncated cubic shape, cuboctahedral shape, truncated octahedral shape, and octahedral shape, were then coated on square manganese nanorods on a few-layer graphene-based electrode as the photosensitizer. Finally, the efficiency of hydrogen production was measured and recorded. The Cu₂O nanoparticles/MnO-MnO₂ nanorods heterojunction generates photoelectrons to reduce hydrogen ions into hydrogen gas. The manganese dioxide nanorods were combined with cuprous oxide multi-shaped nanoparticles to be simultaneously utilized in hydrogen production as a photochemical water-splitting solar cell. The highest rate of hydrogen generation is 33.0 mL/min m² under solar simulation radiation. This study highlights the significance of a back electron-hole recombination loss and transportation process on the surface of a water-splitting photocathode, retarding the appearance of the photocurrent and requiring a greater amount of energy from a solar device.