Nonlinear optical polarization and heterostructure synergistically boosted the built-in electric field of CeF3/LiNbO3 for a higher photocatalytic nitrogen reduction activity

The built-in electric field as a directly driven force plays a key role in realizing the high efficiency of photoinduced carrier separation and transfer. It is an interesting but challenging problem to explore the synergistic nonlinear optical polarization electric field and the heterostructure interfacial electric field to enhance the builtin electric field of the photocatalyst. Herein, a nonlinear optical material i.e. lithium niobate (LiNbO3) was synthesized through a sol-gel process, then directly in-situ loading cerium fluoride (CeF3) semiconductor by a microwave-assisted hydrothermal method to obtain CeF3/LiNbO3 heterojunction. The effect of CeF3 loadings was investigated by photoluminescence characterization, and the optimum amount was at 5 wt%. The nonlinear optical polarization was evaluated through the second harmonic generation (SHG) test, and the SHG signal of 5 wt% CeF3/LiNbO3 was 3.5-fold than that of potassium dihydrogen phosphate (KH2PO4, a typical nonlinear optical material) reference, revealing a high polarization intensity. The 5 wt% CeF3/LiNbO3 exhibits the highest photocatalytic N2 reduction activity under simulated sunlight, which is 6.3-fold of pure LiNbO3. This work highlights the enhanced built-in electric field by rationally constructing nonlinear optical material/semiconductor heterostructure, thus achieving high photocatalytic activity.

Automated summary

The enhancement of built-in electric field by constructing nonlinear optical material/semiconductor heterostructure leads to high photocatalytic activity.