Jem 2011

X-ray diffraction (XRD) was performed with the help of an X-ray diffractometer (Rigaku Co., Japan) complete with a Ni filter (λ = 0.154 nm) and a Cu Kα tube. Fourier transform infrared (FTIR) was conducted by using a Nicolet 6700 spectrometer (Nicolet Instrument Co.). The structures of ZIF-67, CoAl-LDH and CoAl-LDH@ZIF-67 were observed by TEM (Hitachi model H-800, JEM-2011, Japan Electron Optics Laboratory). Thermogravimetric analysis (TGA) was obtained using a Q5000 thermal analyzer (TA Instruments Inc., New Castle, DE, USA) under a nitrogen flow of 25 mL min⁻¹. The fire safety of polymer materials was measured by cone calorimeter test according to ASTM E1354/ISO 5660. The morphology of the remaining char acquired from the cone test was investigated using scanning electron microscopy (SEM, Hitachi SU-8010, Japan). Raman spectroscopy was processed with a RM-1000 laser Raman spectrometer (Renishaw Co., UK) with excitation supplied in backscattering geometry by a 514.5 nm argon laser line.

The morphology and structure of the as-prepared photocatalysts were characterized by SEM (Hitachi S-4800) and TEM (JEM-2011, Hitachi Co.) with an FEI Tecnai G20. The crystal phase structures were characterized by XRD (X’Pert PRO SUPER, Philips Co.) with Cu Kα radiation at 40 kV and 40 mA. UV−vis DRS was performed by a spectrometer (Lambda 650S, PerkinElmer Co.) in the range of 250 to 800 nm, and BaSO₄ was used as a reference material before measurements. The PL spectra were obtained by a fluorescence spectrometer with an excitation wavelength of 350 nm (JY Fluorolog-3-Tou, Jobin Yvon Co.). The specified surface areas were measured through a BET method with a Builder 4200 instrument (Tristar II 3020 M, Micromeritics Co.). The surface atomic compositions were analyzed by XPS using an ESCALAB 250 spectrometer (Thermo Fisher Inc.). The surface properties of the photocatalysts were determined by FTIR (Vertex 70, Bruker Co.) using the KBr pellet technique. ESR measurements were performed on an ESR spectrometer (ER200-SRC, Bruker Co.). The C L-edge and N L-edge XANES spectra were recorded on the BL12B beamline at the National Synchrotron Radiation Laboratory in Hefei, China.