Vacancy mediated Z-scheme charge transfer in a 2D/2D La2Ti2O7/g-C3N4nanojunction as a bifunctional photocatalyst for solar-to-energy conversion

The rational design of low-dimensional heterostructures with defects is a effective way to tackle the sophisticated challenge of harvesting solar energy to generate clean fuels such as H(2)and C1 products. Herein, we designed 2D/2D La2Ti2O7/g-C(3)N(4)nanocomposites with abundant oxygen vacancies as an efficient visible light-driven bifunctional photocatalyst for H(2)evolution and CO(2)reduction reactions. Through both experimental and DFT study, a defined oxygen vacancy in La(2)Ti(2)O(7)was confirmed. The oxygen vacancy mediated Z-scheme mechanism verified by ESR analysis plays a significant role in the generation of clean fuels, leading to H-2, CH3OH and CO generation with a much higher yield than that of defective La(2)Ti(2)O(7)and g-C(3)N(4)alone. These 2D/2D nanojunction induces a rapid electron injection from the defect sites of La(2)Ti(2)O(7)nanosheets to g-C(3)N(4)nanosheets and prolong the charge carriers' lifetime, thereby leading to high reducing power for clean fuel generation.