Plasmonic photocatalyst Au/g-C3N4/NiFe2O4 nanocomposites for enhanced visible-light-driven photocatalytic hydrogen evolution

Abstract

A Au/g-C₃N₄/NiFe₂O₄ nanocomposite was successfully prepared and characterized, and it exhibited a significant visible-light-driven photoactivity for hydrogen production. The results suggested that NiFe₂O₄ was closely coupled with flake-like g-C₃N₄ and Au nanoparticles were successfully loaded onto the surface of an optimal g-C₃N₄/NiFe₂O₄ nanocomposite. Subsequently, the photocatalytic hydrogen evolution of the as-prepared sample was investigated and optimized, indicating that the optimal Au/g-C₃N₄/NiFe₂O₄ ternary nanocomposite with AuNP loading of 1.0 wt% showed the highest hydrogen generation rate of 1.607 mmol g⁻¹ h⁻¹, which was 30.9 times and 28.7 times higher than the values of pure NiFe₂O₄ and pure g-C₃N₄, respectively, whereas the optimized g-C₃N₄/NiFe₂O₄ binary nanocomposite with NiFe₂O₄ coupled at 49.4% exhibited a hydrogen generation rate of 0.351 mmol g⁻¹ h⁻¹. Interestingly, the photocatalytic hydrogen production mechanism was also tentatively proposed as promoted charge carrier transfer and the strong surface plasmon resonance (SPR) effect of AuNPs via PL, EIS and photocurrent measurements was verified.