Nova 4200e

Crystallographic phases of all the products were investigated by powder X-ray diffraction (XRD, Rigaku D/max2500) with Cu Kα (λ = 1.5406 Å) radiation. The morphologies of the samples were examined by field-emission scanning electron microscopy (SEM, FEI Nova NanoSEM 230) and transmission electron microscopy (TEM; JEOL-JEM-2100F transmission electron microscope). A combined Differential Scanning Calorimetry (DSC)/Thermogravimetric Analysis (TGA) instrument (Netzsch STA449C, Germany) was used to study the reactions during the annealing process and measure the carbon content in CW-LVP. Raman spectra were obtained using a Renishaw INVIA micro-Raman spectroscopy system. Nitrogen adsorption-desorption measurements were conducted at 77K (NOVA 4200e, Quantachrome Instruments).

BT-An@Zetag composite samples were analyzed using an X-ray diffractometer (Shimadzu XRD-7000, Tokyo, Japan with an X-ray wavelength Cu detector). Scanning electron microscopy was used to analyze the morphological topographies of BT-An@Zetag composites (SEM, JEOL JSM-6610 LV, Tokyo, Japan). Thermal gravimetric analysis (TGA-51 Shimadzu, Tokyo, Japan) and DSC were used to assess thermal changes across a temperature range of 25–600 °C (Shimadzu DSC-60 Plus, Tokyo, Japan). Raman spectrometer (Shimadzu IR–Tracer 100 Fourier Transform Infrared Spectrophotometer, Tokyo, Japan) was used to determine the Raman spectra of the BT-An@Zetag composite (HOUND UNCHAINED LABS spectrometer, Berlin, Germany). A NOVA 4200e was used to evaluate the nitrogen adsorption–desorption isotherms at 77 K (Quantachrome Instruments, Boynton Beach, FL, USA). The Brunauer–Emmett–Teller (BET) equation and the specific surface area were used to further investigate surface area and pore size.Also, Pore size distributions were also calculated using the Barrett–Joyner–Halenda (BJH) methods. Initial and final concentrations of arsenate were analyzed using Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (TQ-ICP-MS), Thermo Fishers scientific (Waltham, MA, USA).

The Fourier Transform-Infrared Spectroscopy (FT-IR, Bruker Vertex 70v, Billerica, MA, USA) analysis was performed to demonstrate that the activated carbon obtained from the pumpkin seed shell was functionalized with KOH. Scanning Electron Microscopy (SEM, Zeiss EVO 10, Oberkochen, Germany) analysis was used to examine the morphological structure of the adsorbent in detail. The elemental analysis technique (CHNS-932, Leco, Corporation, St. Joseph, MI, USA) was applied to determine the adsorbent’s elemental composition. Further, the adsorbent’s net load was determined using Zeta analysis (Malvern/Zetasizer Nano ZSP, United Kingdom). Additionally, X-ray Photoelectron Spectroscopy (XPS, PHI 5000 VersaProbe, Chanhassen, MN, USA) was utilized to measure the elemental composition of the material’s surface of the material and the binding states of the elements. Brunauer–Emmett–Teller (BET, Nova 4200e Quantachrome Instruments, Boynton Beach, FL, USA) analysis was performed to determine the adsorbent’s surface area of the adsorbent.

The microstructure of cellulose/TiO₂ monoliths was observed with a Scanning Electron Microscope (SEM, S-3000N, Hitachi Ltd., Tokyo, Japan) at 15 kV. Before observation, the samples were cut with a scalpel and coated with a thin layer of gold by an ion sputter apparatus (E-1010 Ion Sputter, Hitachi Ltd., Tokyo, Japan). The specific surface area of the cellulose monolith was measured by a nitrogen adsorption apparatus using the Brunauer-Emmett-Teller (BET) method (NOVA 4200e, Quantachrome Instruments, Boynton Beach, FL, USA). Energy Dispersive Spectroscopy (EDS, Quantax 400, Bruker, Germany) was adopted to investigate the chemical composition of the composite monolith surface. The chemical structure of the composite monolith was analyzed using a Nicolet Is 5 Fourier transform infrared spectrophotometer. The UV-Vis adsorption spectra were carried out using a Shimadzu UV-2550 spectrophotometer. XRD patterns were run on an X-ray diffractometer (Rigaku D/max-2550 VB/PC, RICOH Company, Ltd., Tokyo, Japan) at a scanning rate of 4.0°/min from 5° to 60° (2θ). The measurement was performed under conditions of 40 kV and 30 mA using Cu-Kα radiation (λ = 1.5418 Å). The surface chemical composition of the samples was analyzed by X-ray photoelectron spectroscopy (XPS, AXIS ULTRA DLD, Kratos Analytical Ltd., Manchester, UK) with an Al K_α radiation source.