Electroless plated loading of NiP2/SnO2@rGO for enhanced photocatalytic water splitting

Abstract

In this study, we used the electroless plating to create a layered nickel phosphide and tin oxide-loaded reduced graphene oxide (NiP2/SnO2@rGO) nanocomposites with 7–8 layers, bandgap of 1.95–2.73 eV, and 16.46 μm particle size. Under the real sunlight irradiation the nanocomposites' exhibit photocatalytic H2 production rate of 529.41 μmolg−1h−1 with 2.23 % apparent quantum efficiency at 420 nm under methanol scavenger, which is 13.6 times higher over the pristine GO system (38.9270 μmolg−1h−1). The development of a p–n junction between rGO and NiP2/SnO2, promotes charge transfer process and inhibits recombination, which is responsible for the increased photocatalytic activity. ESR-supported DFT calculation confirm the role of polaron and bipolaron in seamless charge transfer (photoelectron) and formation of cationic NiP2/SnO2@rGO nanocomposite to improve it's ability to harvest light. During electron transfer mechanism of photocatalytic water splitting, cocatalyst NiP2/SnO2 separate of photo e−-h+ pairs, enabling an efficient relay of photoelectron in rGO to reduce H2O in hydrogen gas production, was profoundly supported by the advanced analytical techniques (XRD pattern, UV–Vis spectra, FE-SEM, EDX, steady state PLE spectra, Raman, ESR, XPS, SPV, EIS, etc). The study results to pave the way in significant understanding of the synthesis of NiP2/SnO2@rGO nanocomposites and their uses in water splitting. © 2025 Hydrogen Energy Publications LLC