Hollow Nanorods and Amorphous Co₉S₈ Quantum Dots Construct S-Scheme Heterojunction for Efficient Hydrogen Evolution

The hollow materials have stronger absorption capacity for visible light than other materials due to their special internal cavity structure. In this paper, NiTiO 3 hollow nanorods and Co 9 S 8 QDs were used to prepare composite materials with strong light absorption capacity and photocatalytic hydrogen production activity using an in situ growth method. The results of UV diffuse reflectance spectra prove that the existence of NiTiO 3 hollow nanorod effectively improves the visible light absorption capacity of the composite material. Additionally, the existence of hollow nanorods can evenly disperse Co 9 S 8 QDs on the surface and increase the number of active sites. X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and electrochemical measurements further attest that the S-scheme heterojunction constructed between the two semiconductors not only provides a special transmission path for carrier transfer but also retains more useful electrons and holes that participate in the hydrogen evolution reaction. Therefore, the maximum hydrogen production of NiTiO 3 @Co 9 S 8 QDs can reach 5.38 times that of pure Co 9 S 8 QDs. The consequences show that the S-scheme heterojunction constructed by NiTiO 3 has certain development potential in the field of photocatalysis.