A new structure of Pt NF@Ni(OH)2/CdS heterojunction: Preparation, characterization and properties in photocatalytic hydrogen generation

Abstract A novel multi-heterostructured Pt NF@Ni(OH)2/CdS photocatalyst was applied in hydrogen generation from water splitting with (NH4)2SO3 acted as sacrifice. PtNi octahedral nano-particles (PtNi Octa) were synthesized by solvothermal method, and then etched with EDTA-2Na to obtain PtNi nanoframe (NF). The as-prepared PtNi NF was photodeposited on the surface of CdS in (NH4)2SO3 aqueous solution while the hydrogen photo-generation reaction took place. Since Ni ions are very active, easily combined with OH– to form Ni(OH)2, Pt NF@Ni(OH)2/CdS was formed gradually. The activity evaluation experiment reveals that Pt NF@Ni(OH)2/CdS exhibits a high hydrogen production rate of 44.05 mmol/h/g (QE = 58.89%, λ = 420 nm). The multi-heterostructure of Pt NF@Ni(OH)2/CdS photocatalyst was confirmed using XRD, TEM/EDS, XPS, PL, and ESR. The life spans of photo-induced electrons, in descending order, are Pt NF@Ni(OH)2/CdS > PtNi Octa/CdS > CdS, which explained the excellent photochemical and electrochemical properties of Pt NF@Ni(OH)2/CdS. This work provides a new strategy for photocatalyst designing.