Preparation of WO3-reduced graphene oxide nanocomposites with enhanced photocatalytic property

In this work, WO₃-reduced graphene oxide (RGO) nanocomposite was synthesized via a simple one-pot hydrothermal method. The synthesized nanocomposite was characterized by SEM, XRD, EDX, UV–vis spectroscopy, N₂ adsorption/desorption, photocurrent response, electrochemical impedance spectroscopy and Raman spectroscopy. The superior contact between WO₃ and RGO sheets in the nanocomposite facilitates the photocatalytic degradation of methylene blue and evolution of oxygen. The cause of the enhanced photocatalytic performance could ascribe to the highly facilitated electron transport by the synergistic effect between WO₃ and RGO sheets, as well as suppressing the electron hole pair recombination in the nanocomposite.     

Facile synthesis of WO3 nanorods/g-C3N4 composites with enhanced photocatalytic activity

In this paper, WO₃ nanorods (NRs)/g-C₃N₄ composite photocatalysts were constructed by assembling WO₃ NRs with sheet-like g-C₃N₄. The as-synthesized photocatalysts were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, UV–vis diffuse reflectance spectroscopy and photoluminescence. The photocatalytic activity of the photocatalysts was evaluated by degradation of Rhodamine B (RhB) under simulated sunlight irradiation. Compared to pristine WO₃ NRs and g-C₃N₄, WO₃ NRs/g-C₃N₄ composites exhibit greatly enhanced photocatalytic activities. The enhanced performance of WO₃ NRs/g-C₃N₄ composite photocatalysts was mainly ascribed to the synergistic effect between WO₃ NRs and g-C₃N₄, which improved the photogenerated carrier separation. A possible degradation mechanism of RhB over the WO₃ NRs/g-C₃N₄ composite photocatalysts was proposed.     

One-pot synthesis of 3D porous Bi7O9I3/N-doped graphene aerogel with enhanced photocatalytic activity for organic dye degradation in wastewater

The compound Bi₇O₉I₃ has been considered as a promising candidate for organic dye degradation in wastewater, but it has relatively low photocatalytic activity and difficulties in the recycling processes. In this work, a novel floating 3D porous Bi₇O₉I₃/N-doped graphene aerogel (Bi₇O₉I₃/NGA) composite was successfully synthesized through a facile hydrothermal route. The Bi₇O₉I₃/NGA composite exhibited highly enhanced photocatalytic performance toward degrading rhodamine B under visible-light irradiation, which increased 6.0 and 2.3 times compared with the Bi₇O₉I₃ and Bi₇O₉I₃/GA, respectively. The enhancement of photocatalytic degradation activity could be ascribed to the extensively promoted charge generation and migration efficiency, visible light utilization ability and reactive oxygen species production. Besides, the special 3D macroscopic block structure of Bi₇O₉I₃/NGA allowed it to float, making it easy to recycle. The photocatalytic degradation efficiency of Bi₇O₉I₃/NGA composite still could reach up to 92.7% after four consecutive cycles and presented satisfactory stability and reusability. Moreover, a possible photocatalytic degradation mechanism was revealed by radical species trapping and semi-quantitative analyses experiments.