Hierarchical Ultrathin Layered GO-ZnO@CeO2 Nanohybrids for Highly Efficient Methylene Blue Dye Degradation.

Highly efficient interfacial contact between components in nanohybrids is a key to achieving great photocatalytic activity in photocatalysts and degradation of organic model pollutants under visible light irradiation. Herein, we report the synthesis of nano-assembly of graphene oxide, zinc oxide and cerium oxide (GO-ZnO@CeO2) nanohybrids constructed by the hydrothermal method and subsequently annealed at 300 °C for 4 h. The unique graphene oxide sheets, which are anchored with semiconducting materials (ZnO and CeO2 nanoparticles), act with a significant role in realizing sufficient interfacial contact in the new GO-ZnO@CeO2 nanohybrids. Consequently, the nano-assembled structure of GO-ZnO@CeO2 exhibits a greater level (96.66%) of MB dye degradation activity than GO-ZnO nanostructures and CeO2 nanoparticles on their own. This is due to the thin layers of GO-ZnO@CeO2 nanohybrids with interfacial contact, suitable band-gap matching and high surface area, preferred for the improvement of photocatalytic performance. Furthermore, this work offers a facile building and cost-effective construction strategy to synthesize the GO-ZnO@CeO2 nanocatalyst for photocatalytic degradation of organic pollutants with long-term stability and higher efficiency.

Three-dimensional porous MoS2 nanobox embedded g-C3N4@TiO2 architecture for highly efficient photocatalytic degradation of organic pollutant.

Herein, a simple, highly efficient and stable MoS2 nanobox embedded graphitic-C3N4@TiO2 (g-CN@TiO2) nanoarchitecture was synthesized by a facile solvothermal approach. The nano-hybrid photocatalyst was constructed by TiO2 nanoparticles anchored on the surface of g-CN nanosheets. Then highly crystalline three-dimensional porous MoS2 nanobox was homogeneously distributed on the g-CN@TiO2 surface. The g-CN@TiO2/MoS2 hybrid achieved a high photocatalytic degradation efficiency of 97.5% for methylene blue (MB) dye pollutant under visible-light irradiant in an hour which was much better than TiO2@MoS2, g-CN@TiO2, MoS2, TiO2 and g-CN. Furthermore, the reaction rate (k) value of g-CN@TiO2/MoS2 for MB dye is as high as 3.18 X 10-2 min-1, which is ~ 2.65 times better than those of g-CN@TiO2 and MoS2. This work presents a rational structure design, interfacial construction and suitable band gap strategy to synthesize advanced nano-hybrid photocatalyst for degradation of organic pollutant with excellent performance and long-term stability.

Hierarchical ultrathin layered MoS2@NiFe2O4 nanohybrids as a bifunctional catalyst for highly efficient oxygen evolution and organic pollutant degradation.

Rational design and highly efficient dual-functional catalyst are still difficult to develop for electrocatalytic oxygen evolution reaction and degradation of RhB dye pollutant. Herein, we report a highly efficient "bandgap matching and interfacial coupling" strategy to synthesize nano-assembled ultrathin layered MoS2@NiFe2O4 (MS@NiFeO) bifunctional catalyst constructed by the hydrothermal route and subsequently amine-hydrolysis. The OER performance of the prepared MS@NiFeO catalyst delivers a low overpotential of 290 mV at 10 mA/cm2 and Tafel slope is 69.2 mV dec-1 in an alkaline solution. In addition, the nano-assembled ultrathin layered structure of MS@NiFeO showed a highly efficient (96.37%) RhB dye degradation performance than that of MoS2 nanosheets and NiFe2O4 nanostructures. Unique nanostructure of ultrathin layered MS@NiFeO with suitable band matching, interfacial charge transfer, high surface area and more active sites favored for the enhancement of the catalytic activity. This work presents an unpretentious construction and low-cost production strategy to synthesize bifunctional hybrid catalyst for oxygen evolution reaction as well as degradation of organic pollutant with superior efficiency and longer stability.