In Situ Formation of Graphene Stabilizes Zero-Valent Copper Nanoparticles and Significantly Enhances the Efficiency of Photocatalytic Water Splitting

There is a growing need for new techniques to synthesize metallic copper nanoparticles due to their remarkable use in many advanced technologies. Herein, a novel method to synthesize stable and nonagglomerated zero-valent copper nanoparticles (ZVCNPs) via the in situ formation of reduced graphene oxide (rGO) during the electrospinning process in the presence of polyvinylpyrrolidone as a carbon source is presented. X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, transmission electron microscopy, and X-ray photoelectron spectroscopy techniques were used to investigate the morphology, structure, and composition of the fabricated materials. The synthesized ZVCNPs were coupled with TiO2 nanofibers and rGO to form an efficient photoactive material to photocatalytically produce hydrogen via water splitting, resulting in 344% increase in the hydrogen yield compared to that of TiO2 nanofibers. The density functional theory (DFT) calculations showed that the ZVCNPs enhance the charge transfer and lower the energy needed for photocatalytic water splitting. This study suggests a novel method for metallic copper stabilization and illustrates the effect of metallic copper as a catalyst for the in situ formation of rGO.