Visible Light Harvesting and Spatial Charge Separation over the Creative Ni/CdS/Co3O4 Photocatalyst

In this case, the validity of the work on a stable nickel, cadmium sulfide, and spinel cobalt oxide composite proton-reduction photocatalyst is reported. N nanoparticles (acting as the hydrogen collector) and Co3O4 nanoparticles (acting as the oxygen collector) are uniformly assembled on the surface of CdS nanorods, the synergetic enhancement of light harvesting and charge management was simultaneously obtained, and the efficient hydrogen evolution was revealed here as well. The Ni/CdS/Co3O4 composite photocatalyst shows a high H-2 evolution yield of 207.63 mu mol in 5 h, which is 8.44 times greater than the pristine CdS (24.61 mu mol). Here, CdS nanorods with a rodlike structure provide a large number of attachment sites for Ni nanoparticles and the Co3O4 nanoparticles. The detailed inner reason was comprehensively studied and understood by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, and especially by particular investigation of their photoelectrochemical properties with photocurrent, voltammetric scanning, fluorescence spectra, and so forth. The high photocurrent response, the lower overpotential [-0.42 V vs saturated calomel electrode (SCE)], the faster electron transfer rate (k(et) = 3.58 X 10(8) s(-1)), and the short fluorescence lifetime (2.74 ns) supported the efficient spatial charges transfer between CdS and Ni as well as Co3O4. The simultaneous loading of bicocatalysts can significantly improve the photoinduced spatial charge separation of CdS because Ni nanoparticles act as electron collectors to rapidly transfer electrons from CdS, while Co3O4 acts as a holes collector to quickly transfer holes, enhancing its photocatalytic performance as well.