Multiple-phases LaFeO3 decorated with sea-urchin-like Au nanoparticles for photoelectrochemical hydrogen generation from bio-ethanol and 1-butanol

Narrow-band-gap LaFeO₃ (approximately 2.1 eV) has good thermal stability, and applications for light-driven water splitting. Thus, heterojunction catalyst containing LaFeO₃ and Au nanoparticles (NPs) are investigated for photoelectrochemical hydrogen production. The use of a citric acid or KOH modifier and calcination yields different LaFeO₃ particle morphologies and phases (La(OH)₃ alone or La(OH)₃ and La₂O₃, respectively), which affect the Au NPs coverage ratio. In addition, the formation of a heterojunction, the surface-plasma resonances (SPRs) effect, and the unique nanospikes on the Au NPs, red-shift happens in the light wavelength and reduce the photonic extinction to less than 2.1 eV. Further, in ethanol and l-butanol under AM 1.5G irradiation, more hydrogen is generated in the former than the latter at all tested temperatures. In addition, the activation energy for the formation of hydrogen is lower in ethanol than in 1-butanol. Finally, an amorphous structure is beneficial for photocatalysis.