Mechanistic study on photocatalysis properties of Cu3N/TiO2 heterojunction nanorods

The Cu3N/TiO2 3 N/TiO 2 heterojunction nanorods are fabricated by a magnetron sputtering method. The morphology, light absorption, and photoelectrochemical (PEC) properties are studied. Compared with the pristine TiO2, 2 , the heterojunction takes a lower optical band gap of about 1.3 eV, which can enhance the utilization sunlight. The PEC tests show that the Cu3N/TiO2 3 N/TiO 2 heterojunction with N2 partial pressure 100 % can improve the photocatalytic efficiency significantly. The photocurrent density of Cu3N/TiO2 3 N/TiO 2 is 4 times higher than that of TiO2, 2 , which can be attributed by the smaller band gap of Cu3N/TiO2 3 N/TiO 2 and the enhanced charge separation of heterojunction. By the first-principles calculation method, it was determined that the Cu3N/TiO2 3 N/TiO 2 heterojunction presents type II band alignment. suggests that the charge transfer mechanism of TiO2/Cu3N 2 /Cu 3 N junction is sensitive to the experimental conditions. Z-scheme and p-n junction scheme can be formed with low and high N2 2 partial pressure, respectively. Moreover, the spin polarized states are found near the interface of Cu3N/TiO2, 3 N/TiO 2 , which can modulate the interfacial charge transfer. We can also predict that the PEC reaction of the TiO2/Cu3N 2 /Cu 3 N heterojunction structure can be modulated by the magnetic field.