A novel black TiO 2 /ZnO nanocone arrays heterojunction on carbon cloth for highly efficient photoelectrochemical performance

ZnO nanocone arrays (NCAs) decorated with black TiO 2 nanoparticles (B-TiO 2 NPs) were uniformly anchored on the surface of carbon cloth (CC) directly by a simply electrochemical deposition method. Thus a novel B-TiO 2 NPs/ZnO NCAs-CC hierarchical heterostructure was formed. It displayed superior performance and achieved a higher photocurrent over 0.4 mA$cm -2 before the onset of the dark current, attributed to the separation of the photogenerated electron-hole pair. Based on the B-TiO 2 NPs/ZnO NCAs-CC heterostructure, the catalyst was fabricated for promoting the separation of charge carriers. Moreover, the introduction of Ti 3+ and oxygen vacancies on the surface of TiO 2 NPs expanded the absorption band edge and enhanced the electrical conductivity as well as the charge transportation on the catalytic surface. It indicates that the B-TiO 2 NPs/ZnO NCAs-CC composite is beneficial to the improvement of the photoelectrochemical (PEC) activity.