PtNixCoy concave nanocubes: synthesis and application in photocatalytic hydrogen generation

Abstract

PtNi_xCo_y concave nanocubes (CNCs) are synthesized using a hydrothermal method and decorated on the surface of CdS via a fast photo-deposition method (denoted as PtNi_xCo_y/CdS). The photocatalytic hydrogen evolution activity is investigated under visible light irradiation, and Pt/CdS exhibits a good hydrogen generation rate of about 37.80 mmol h⁻¹ g⁻¹ (QE = 44.64%, λ = 420 nm). Moreover, the performance of the PtNi_xCo_y CNCs is enhanced with the addition of Ni and Co, and the hydrogen generation rate of PtNiCo/CdS is as high as 50.60 mmol h⁻¹ g⁻¹ (QE = 56.82%, λ = 420 nm), which is 1.3-fold higher than that of Pt/CdS and also significantly higher than those of PtNi/CdS (42.71 mmol h⁻¹ g⁻¹) and PtCo_0.5/CdS (40.33 mmol h⁻¹ g⁻¹). The high photocatalytic performance could be explained by the high surface index and the highly unsaturated atom coordination of PtNiCo CNCs, and the synergistic effects of the tri-metals, which enhance the capturing ability of photo-generated electrons, and finally result in high charge separation and high charge transport between the alloy CNCs and CdS at the interface.