Black phosphorus nanosheets and ZnAl-LDH nanocomposite as environmental-friendly photocatalysts for the degradation of Methylene blue under visible light irradiation

摘要

Environmental-friendly photocatalysts and high utilization of solar energy have attracted much attention; hence, it is important to develop highly efficient and nontoxic photocatalysts. As a novel two-dimensional semiconductor, black phosphorus nanosheets (BPNs) have gotten extensive solicitude due to their tunable bandgap and high carrier mobility. Here, we report a new kind of environmental-friendly nanocomposite consisting of ZnAl-layered double hydroxides (LDH) and BPNs, and is obtained by electrostatic self-assembly method. The acquired photocatalysts were studied by XRD, TEM, EDX, UV-Vis diffuse reflectance spectra, mott-schottky, EIS and ESR techniques so as to gain the information on morphology, structure and properties. Compared to pristine ZnAl-LDH and BPNs, the composite photocatalyst shows the best photocatalytic activity for methylene blue (MB) degradation under visible light irradiation, and the 99% of MB was degraded in 80 min. The improvement of photocatalytic performance is mainly because BPNs provide an additional transfer channel of electrons and holes. The nanocomposites have opened up a new idea to construct black phosphorus (BP) based photocatalysts for environmental remediation.