The role of citric acid modifiers addition in the preparation of TiO2 nanoparticles with the solvothermal method

Abstract

In this study an investigation of solvothermal methods was carried out, using the precursor titanium butoxide in ethanol media, and using citric acid as a modifier. The modification of the modifier is done to ensure particle size and prevent TiO2-NP aggregation, which is used as a capping agent and simultaneously as a dispersion of TiO2-NP in the polymer matrix. The results of TiO2-NP powder modified with citric acid (CA-TiO2-P) were characterized by FTIR spectroscopy, UV-Vis DRS, SEM EDS, XRD, TEM, HR-TEM and SAED. Citric acid success to modify TiO2-NP is shown at FTIR spectrums at 2905 cm−1 and 2841 cm−1 which are stretching vibrations of C-H bonds in the methylene group (CH2); and at 1374 cm-1 which is a vibration oscillation of the carboxylic group. The results of XRD characterization shows anatase phase, diffraction patterns from facet (101), (004), (200), (105) and (204). It was observed that the crystallite size of CA-TiO2-NP was smaller than TiO2-NP bare. This result is supported by of HRTEM and SAED characterization about d-spacing value. Photographs of TEM images show a range of particle sizes of 3-6 nm (CA-TiO2) and 8-14 nm (TiO2-NP bare). From the results of the characterization it can be concluded that the addition of citric acid modifier in the solvothermal method has succeeded in producing particle size control obtained by TiO2-NP with smaller size and suitable morphology. Details of characterization and role modifiers will be discussed in this paper.