Optima 3300dv spectrometer

Powder XRD patterns were recorded on a Bruker D8A25 diffractometer with Cu Kα radiation (λ = 1.54184 Å) operating at 30 kV and 25 mA. UV-vis spectra were collected on a Shimadzu UV-visible UV-2550 spectrometer. FTIR spectra of the framework vibrations were recorded on a Perkin Elmer Spectrum One FTIR spectrophotometer. The morphology and size of the crystals were imaged on a JEOL JSM-6510A scanning electron microscope (SEM). TEM images were obtained using a FEI Tecnai G20 at an accelerating voltage of 200 kV. HRTEM images were obtained using a FEI Titan G² 60-300 at an accelerating voltage of 200 kV. N₂ adsorption/desorption isotherms were determined by a QuantachromeiQ-MP gas adsorption analyzer at 77.35 K. Before the nitrogen adsorption, the samples were degassed at 523 K for 3 h. The BET surface area was calculated based on the Brunauer–Emmett–Teller (BET) equation, and the pore distribution and total pore volume (at a relative pressure of P/P₀ = 0.98) were calculated by the Barrett–Joyner–Halenda (BJH) method. Inductively coupled plasma (ICP) analysis was performed on a Perkin-Elmer Optima 3300Dv spectrometer. Elemental analyses (C, H, and N) were conducted on a Vario Micro elemental analyzer. Thermogravimetric analysis (TGA) was performed on a TASDTQ600 analyzer with a temperature-programmed rate of 10 K min^–1 in air.

The NMR experiments were performed on a Varian Infinity-plus 400 spectrometer operating at a magnetic field strength of 9.4 T. The resonance frequencies at this field strength were 161.9 and 104.2 MHz for ³¹P and ²⁷Al, respectively. A Chemagnetics 5 mm triple-resonance MAS probe with a spinning rate of 8 kHz was used to acquire the ³¹P and ²⁷Al NMR spectra. The ²⁷Al MAS spectra were acquired using a single pulse sequence with a short radio frequency (rf) pulse of 0.5 s (corresponding to a π/15 flip angle) and a pulse delay of 1.0 s. The pulse length for ²⁷Al was measured using a 1 M Al(NO₃)₃ solution. The single-pulse ³¹P MAS NMR experiments with ¹H decoupling were performed with a 90° pulse width of 4.6 ms, a 180 s recycle delay, and a ¹H decoupling strength of 42 kHz. The chemical shifts were referenced to an 85% H₃PO₄ solution for ³¹P and a 1 M Al(NO₃)₃ solution for ²⁷Al.
The powder X-ray diffraction (XRD) patterns were recorded on a Rigaku diffractometer that was equipped with a graphite monochromator using Cu Kα radiation (λ = 1.5418 Å). The pH values of the liquid phases were measured with a Sartorius PB-10 pH metre. The inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis was performed on a Perkin-Elmer Optima 3300DV spectrometer.

Total organic carbon (TOC) and total carbon (TC) were determined using a TOC analyzer (TOC-V; Shimadzu, Kyoto, Japan). Chemical oxygen demand (COD) was measured using a water test kit (HS-COD-MR; Humas, Korea) and UV-spectrometer (DR2010; Hach, Loveland, CO, USA). Nutrients (ammonium, nitrate, nitrite, and phosphate) were analyzed using ion chromatography (883 Basic IC plus, Metrohm AG, Herisau, Switzerland); a Metrosep A Supp 5- 150/4.0 (Metrohm AG; Herisau, Switzerland) column was used for anion analysis and a Metrosep C4-150/4.0 (Metrohm AG; Herisau, Switzerland) was used for cation analysis. Trace elements were determined using an inductively coupled plasma optical emission spectrometry (ICP-OES) on a Perkin-Elmer Optima 3300 DV spectrometer.