An all-solid-state Z-scheme TiO2/ZnFe2O4 photocatalytic system for the N2 photofixation enhancement

Abstract

In this report, environmental and energy issues were deal with a Z-scheme photocatalytic system toward the synthetic ammonia by N2 photofixation. Different from traditional double-charge-transfer model, a direct all-solid-state Z-scheme system of modified TiO2 (MT) loaded with ZnFe2O4 (ZFO) was obtained by solvothermal-calcination method, in which calcination temperature is crucial for the mesoporous structure and formation of Z-scheme TiO2/ZnFe2O4. At ambient temperature and pressure, the MT/ZFO photocatalyst presented the ammonia generation rate of about 1.48 μmol/L/min, which is higher than that of single MT or ZFO. The photocatalytic activity enhancement of ammonia generation was attributed to the Z-scheme charge transfer model with a more negative reduction potential in the conduction band of ZnFe2O4. Combining the commonly TiO2 and ZnFe2O4 by a special method shows a desirable Z-scheme photocatalytic system, which can be extended to the fabrication of other Z-scheme photocatalyst according to the various application need.