摘要：Recently, the g-C3N4-based heterojunctions have been widely investigated for their greatly enhanced photogenerated carrier separation efficiency. However, most studies are based on the study of g-C3N4 powders. In this study, a novel TiN/C3N4/CdS nanotube arrays core/shell structure is designed to improve the photoelectrochemical catalytic performance of the g-C3N4-based heterojunctions. Among them, TiN nanotube arrays do not respond to simulated solar light, and thus only serve as an excellently conductive nanotube arrays backbone for supporting g-C3N4/CdS heterojunctions. g-C3N4 prepared by simple liquid atomic layer deposition, which possesses appropriate energy band position, mainly acts as the electron acceptor to transport and separate electrons. Deposited CdS quantum dots obtained by successive ionic layer adsorption reaction can effectively absorb visible light and thus act as a light absorber. The TiN/C3N4/CdS nanotube arrays core/shell structure could be verified by X-ray diffractions, Raman spectra, scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy elemental mappings and X-ray photoelectron spectroscopy. Compared with TiN/C3N4 nanotube arrays, the TiN/C3N4/CdS samples greatly improve the photoelectrochemical performance, which can be evaluated by photoelectrochemical tests and photoelectrochemical catalytic degradation. Especially, the optimized photocurrent density of TiN/C3N4/CdS has almost 120 times improvement on TiN/C3N4 at 0 V bias under simulated sunlight, which can be ascribed to the effective expansion of the light absorption range and separation of electron-hole pairs.