Homojunction of Oxygen and Titanium Vacancies and its Interfacial n–p Effect

Abstract

Abstract The homojunction of oxygen/metal vacancies and its interfacial n–p effect on the physiochemical properties are rarely reported. Interfacial n–p homojunctions of TiO 2 are fabricated by directly decorating interfacial p‐type titanium‐defected TiO 2 around n‐type oxygen‐defected TiO 2 nanocrystals in amorphous–anatase homogeneous nanostructures. Experimental measurements and theoretical calculations on the cell lattice parameters show that the homojunction of oxygen and titanium vacancies changes the charge density of TiO 2 ; a strong EPR signal caused by oxygen vacancies and an unreported strong titanium vacancies signal of 2D 1 H TQ‐SQ MAS NMR are present. Amorphous–anatase TiO 2 shows significant performance regarding the photogeneration current, photocatalysis, and energy storage, owing to interfacial n‐type to p‐type conductivity with high charge mobility and less structural confinement of amorphous clusters. A new “homojunction of oxygen and titanium vacancies” concept, characteristics, and mechanism are proposed at an atomic‐/nanoscale to clarify the generation of oxygen vacancies and titanium vacancies as well as the interface electron transfer.