Vertex 70 fourier transform infrared spectroscopy ftir

The morphology of the ALG particles was observed by a scanning electron microscope (SEM, S-4800, Hitachi, USA) and a transmission electron microscope (TEM, Tecnai G2 F20, FEI Co., USA). The size distribution of the ALG particles was characterized by a laser granularity analyzer (NANOTRAC FLEX, Microtrac MRB, Germany). The localized nanoscale mid-IR measurement was carried on a Nano-IR2 system (AFM-IR, Anasys Instruments, CA, USA) over the range of 900–1500 cm⁻¹. In the mid-IR measurement, the tapping-mode atomic force microscope (AFM) tip was used to interact with the sample. The resonance frequency of the tapping tip was approximately 75 kHz. By scanning the surface, an AFM tip could get the morphological and optical state of the sample due to the near-field interaction between the tip and the sample. The infrared spectrum was obtained by a VERTEX 70 Fourier Transform infrared spectroscopy (FTIR; Bruker, Germany) over the range of 400–4000 cm⁻¹.

Phase structures were characterized by a Philips/X’Pert PRO X-ray powder diffractometer (XRD) equipped with Cu Kα radiation (λ = 0.15406 nm) (PANalytical B.V., Almelo, The Netherlands), and the morphologies of samples were explored with a Tecnai G2 20 transmission electron microscopy (TEM) with a working voltage of 200 kV (FEI company, Hillsboro, OR, USA). The composition and chemical state of samples were examined with a Kratos/Axis Ultra DLD-600 W X-ray photoelectron spectrometer (XPS, Shimadzu/Kratos company, Kyoto, Japan). The specific surface area and pore size distribution were determined with a Micromeritics ASAP2020 surface area analyzer (American Mike Instruments, Atlanta, GA, USA). The defect and disorder degree of materials were analyzed with a LabRAM HR800 Raman spectroscopy (Horiba JobinYvon, Paris, France). A Bruker VERTEX 70 Fourier transform infrared spectroscopy (FT-IR) equipped with a KBr beam splitter in the regular scanning region of 4000–400 cm⁻¹ (Bruker company, Berlin, Germany) was carried out to determine chemical functional groups. The electron paramagnetic resonance (EPR) signals were detected on a Bruker X-band A200 spectrometer (Bruker company, Berlin, Germany). The electrochemical measurements were tested via a CHI660 electrochemical workstation with a standard three-electrode system (Shanghai Chenhua Instruments Co., Shanghai, China).