Nickel oxide/Au porous nanobelts: Synthesis and visible light-driven photocatalytic hydrogen production

Nickel oxide/Au porous nanobelts were synthesized by hydrolysis of nickel (II) sulfate in the presence of Au nanoparticles under hydrothermal condition and subsequent calcination of Ni(OH) 2 /Au precursor in air. XPS measurement indicated the existence of both NiO and Ni 2 O 3 in nickel oxide/Au porous nanobelts. Heterojunctions between NiO and Ni 2 O 3 , as well as between NiO and Au, were observed in HRTEM images. Under visible light irradiation (λ > 420 nm), nickel oxide/Au porous nanobelts effectively produced hydrogen from water in the presence of Na 2 S and Na 2 SO 3 as sacrificial electron donor . The highest rate of hydrogen production over nickel oxide/Au porous nanobelt was 38.5 times higher than that of commercial NiO loaded with the same amount of Au. The photoluminescence spectra and transient photocurrent responses of nickel oxide/Au nanobelts reveal that the improved photocatalytic activity is due to the increased electron–hole separation at NiO Ni 2 O 3 and NiO Au interfaces. This work shows that low-cost nickel oxide could be used as visible light-active photocatalyst for hydrogen production.