Construction of flourinated-TiO2 nanosheets with exposed {001} facets/CdSe-DETA nanojunction for enhancing visible-light-driven photocatalytic H-2 evolution

摘要

Although much significant efforts have been devoted to design highly efficient photocatalysts for addressing energy crisis and environmental issues, it remains challenging to construct a promising and efficient heterostructure among semiconductors for photocatalytic hydrogen (H-2) production under visible-light excitation. Herein, the novel structure with 2D fluorinated-TiO2 nanosheets (F-TiO2 NSs) decorated CdSe-diethylene-triamine nanoflowers (CdSe-DETA NFs) was designed and fabricated by a simple and fast microwave-assisted hydrothermal method. The F-TiO2/CdSe-DETA heterojunction displays enhanced photocatalytic activity in splitting water to produce H-2. Among them, 20%F-TiO2/CdSe-DETA exhibited the highest H-2 evolution rate (12381 mu mmol g(-1) h(-1)), which is 2.92 and 6.44 times greater than that of pristine CdSe-DETA and CdSe, respectively. Meanwhile, 20%F-TiO2/CdSe-DETA composite shows a good stability in the cyclic runs for photocatalytic H-2 evolution. The enhanced activity and reusability are primarily attributed to rapid separation of charge carriers, enrich catalytic active sites as well as strong light absorption capability. Besides, the in-situ growth of a certain amount F-TiO2 NSs with exposed {0 0 1} high-energy facets on surface of inorganic-organic CdSe-DETA NFs greatly helps to strengthen intimate interfacial contact. These results may furnish a reference to fabricate the heterostructures on the basis of CdSe that is extremely insightful for conversion of solar power to H-2 energy.