Titanium dioxide (TiO₂) is a traditional photocatalyst material.However, due to its wide band gap (3.2 eV) and the easy recombination of photogenerated carriers,it is necessary to enhance the effective absorption of sunlight,promote the separation of photogenerated carriers,and inhibit their recombination by doping noble metals,transition metals,anions and constructing heterojunctions.TiO₂/CdS heterojunctions were prepared in two steps.Firstly,TiO₂ nanotube arrays were prepared by multiple voltage anodization.Then,with TiO₂ nanotubes as the base,CdS quantum dots were uniformly deposited inside and outside the nanotubes through chemical bath deposition.The composition,morphology,and optical properties of TiO₂/CdS heterojunctions were characterized by X?ray diffraction,scanning electron microscopy (SEM),transmission electron microscopy (TEM),X?ray photoelectron spectroscopy (XPS),and UV?visible spectroscopy (UV?VIS).The prepared TiO₂/CdS heterojunctions effectively inhibited the recombination of photogenerated carriers,promoted the transfer of excited electrons,and improved the hydrogen production efficiency by photocatalysis.The hydrogen production efficiency of sample TiO₂(1.0)?CdS(1.0) reached 1.30 mmol/（g ? h）,which was 1.67 times that of CdS quantum dots.Finally,according to the experimental analysis,the transfer mechanism of photogenerated electrons on TiO₂/CdS during photocatalytic water splitting for hydrogen was proposed.