**3.7 Fourier transform infrared spectroscopy (FTIR)**

Fourier transform infrared spectroscopy (FTIR) measures the absorption of electromagnetic radiation in the infrared medium (4000–400 cm−1). When a molecule absorbs infrared radiation, the moment of the dipole is somehow altered, and the molecule becomes an active IR. The recorded spectrum contains energy-related bands, bonds, and specific functional groups that provide molecular structures and interactions. Feliu and colleagues used the combined in situ ATR-FTIR and defaulting electrochemical mass spectroscopy to investigate the effect of Pt nanostructures during ethanol oxidation (DEMS). These methods assisted in the electrochemical analysis of adsorbates and the detection of flexible reaction products. Their findings support previous findings, showing that the decomposition products selected were related to the above structures, the formation of Coads in the (100) domains, and the formation of acetaldehyde/acetic acid in 111 domains. One study used carbon-backed NPs (3–8 nm in size) to obtain CO oxidation and a catalytic process was performed

with DRIFTS and quadrupole mass spectrometry (QMS). According to the QMS results, FTIR ratings of adsorbed CO verified Coad and Oad variations in different test phases. While changes in the distribution of CO over different types of Pt sites were also observed. Overall, DRIFTS was considered an essential tool for assessing the local structure of Pt NPs in situ. Shukla et al. published a paper on FTIR oleylamine research. The anterior ligand is bound to FePt NPs in both monodentate and bidentate forms, while oleylamine is bound to FePt and the NH2 group is substantial. In addition, Au/Ag bimetallic NPs are dodecanetiol-soluble and dissolved insoluble solvents incorporated into water/toluene via a two-phase synthetic route [43]. The most important finding from the XPS and FTIR ratings was that Ag atoms were enriched on the outer edge of the hybrid clusters compared to Au atoms. ATR-FTIR was used in another study to assess the effect of Ag NP content on photocatalytic degradation of oxalic acid advertised in TiO2 NPs. Various Ag NP values were tested, and it was found that inserting only a tiny amount (2 percent) significantly improved the photocatalytic performance of TiO2 NPs. NP composite films' location and chemical structure/composition were observed using AFM and XPS. Tzitzios et al. created hexagonal Ni NPs with a diameter of 13–25 nm by reducing nickel stearate in the presence of PEG, oleic acid, and oleylamine. The presence of different groups on the surface of NPs, such as HCvCH- setting in OAC and OAm, was indicted by the FTIR spectra, and the mechanisms for ligand binding in the NP area were also investigated. Haram and its allies have used the hot-shot method to make copper zinc tin sulpho-selenide (CZTSxSe1-x) nanocrystals. For incorporation, the precursors were dispersed in OAm and heated to T > 200°C. OAm advertising on particle surfaces is reflected in FTIR ratings. Feature belts are derived from components present in the OAm molecule and effectively interact with NPs. The number of NP organic ligands is determined [67].
