Search

Gamma-phase cesium lead tri-bromide perovskite nanocrystals (γ-CsPbBr3 NCs) possess potentially photo-catalytic degradation ability and long-term stability. However, their serious aggregation issue decreases their active surface area, and the recombination of photo-generated hole–electron pairs weakens their photo-catalytic property. Furthermore, these NCs can be easily absorbed on the surface of dyes [e.g., methylene blue (MB)] or dissolved in the dye solution during the photo-catalytic degradation process, thus reducing the amount of γ-CsPbBr3 NCs and their photo-catalytic degradation ability. Besides, the residual γ-CsPbBr3 NCs in the photo-catalytic degradation products also present the toxicity issue (containing Pb) and are hazardous to the ecological environment and human health. In the present study, we fabricated γ-CsPbBr3 NCs/polymethyl methacrylate electrospun nanofibrous membranes (γ-CsPbBr3 NCs/PMMA ENMs) by using electrospinning technology to solve the above problems. It is found that the synthesized γ-CsPbBr3 NCs/PMMA ENMs show a large surface area and the abundant functional groups on their surfaces, which are benefit for forming multiple kinds of chemical bonding effect between γ-CsPbBr3 NCs and PMMA ENMs. In addition, γ-CsPbBr3 NCs could disperse homogeneously in or on the surface of PMMA ENMs. These abundant chemical bonds and homogeneous distributions of γ-CsPbBr3 NCs on the surface of PMMA ENMs can significantly decrease the recombination of photo-generated hole–electron pairs and toxicity issue of γ-CsPbBr3 NCs during the photo-catalytic degradation process. Exhilaratingly, γ-CsPbBr3 NCs/PMMA ENMs could maintain a superior photo-catalytic degradation ability toward various dyes and reveal a high photo-catalytic degradation efficiency of 99.18% in 60 min for MB. [ABSTRACT FROM AUTHOR]

We prepared peapod-like titanium dioxide@graphene@carbon (TiO2@GO@C) nanofiber membranes through electrospinning. Due to the porous structure, large surface area, abundant surface functional groups and excellent thermal conductivity, GO can capsulize TiO2 nanoparticles to form a pea-like TiO2@GO structure. Subsequently, TiO2@GO can be wrapped by the carbon nanofiber during an electrospinning process, forming peapod-like TiO2@GO@C nanofiber membranes. The existence of a peapod-like structure is beneficial for enhancing the crystallinity of TiO2, and preventing the phase transformation of TiO2 from anatase to rutile phase at the same time. Furthermore, on the basis of the excellent carrier transport property of GO, the peapod-like TiO2@GO@C structure could also improve the light absorption, reduce recombination of hole–electron pairs, and improve the carrier transport and finally photocatalytic degradation property of methylene blue. Besides, the pea-like TiO2@GO structure shows a dispersion strengthening effect in the carbon nanofibers, preventing the carbon nanofibers from fracture. In particular, by optimizing the heat treatment temperature and additional amount of GO, the peapod-like TiO2@GO@C nanofiber membranes with 0.3 wt% GO show an excellent photocatalytic degradation efficiency of 98.5% in 3 h, and a high strength of 356.07 cN per dtex. [ABSTRACT FROM AUTHOR]