Study of Perfluorophosphonic Acid Surface Modifications on Zinc Oxide Nanoparticles

Abstract

In this study, perfluorinated phosphonic acid modifications were utilized to modify zinc oxide (ZnO) nanoparticles because they create a more stable surface due to the electronegativity of the perfluoro head group. Specifically, 12-pentafluorophenoxydodecylphosphonic acid, 2,3,4,5,6-pentafluorobenzylphosphonic acid, and (1H,1H,2H,2H-perfluorododecyl)phosphonic acid have been used to form thin films on the nanoparticle surfaces. The modified nanoparticles were then characterized using infrared spectroscopy, X-ray photoelectron spectroscopy, and solid-state nuclear magnetic resonance spectroscopy. Dynamic light scattering and scanning electron microscopy-energy dispersive X-ray spectroscopy were utilized to determine the particle size of the nanoparticles before and after modification, and to analyze the film coverage on the ZnO surfaces, respectively. Zeta potential measurements were obtained to determine the stability of the ZnO nanoparticles. It was shown that the surface charge increased as the alkyl chain length increases. This study shows that modifying the ZnO nanoparticles with perfluorinated groups increases the stability of the phosphonic acids adsorbed on the surfaces. Thermogravimetric analysis was used to distinguish between chemically and physically bound films on the modified nanoparticles. The higher weight loss for 12-pentafluorophenoxydodecylphosphonic acid and (1H,1H,2H,2H-perfluorododecyl)phosphonic acid modifications corresponds to a higher surface concentration of the modifications, and, ideally, higher surface coverage. While previous studies have shown how phosphonic acids interact with the surfaces of ZnO, the aim of this study was to understand how the perfluorinated groups can tune the surface properties of the nanoparticles.

A Multilayered Electron Extracting System for Efficient Perovskite Solar Cells

“…The P 2p 3/2 peak at 133.2 eV is attributed to the formation of stable covalent bonds between the Zn oxide surface and the deprotonated phosphine oxide functional group of TPPO. [ 55,56 ] As shown in Figure S6 (Supporting Information), the Zn 2p spectrum does not undergo any change in AZO and AZO:TPPO mixture. These results further demonstrate the chemical interaction between TPPO and AZO, and the possibility of the formation of new species.…”

Effects of metal oxide surface doping with phosphonic acid monolayers on alcohol dehydration activity and selectivity

“…To our knowledge, this is the first report of the functionalization of CeO2, CuO, MgO, SnO2, and V2O5 with phosphonic acids. Functionalization of Al2O3, [11][12][13] Fe2O3, [14] TiO2, [11][12][13]15] WO3, [16] ZrO2, [11,12,17] and ZnO [18][19][20][21] has been reported previously, however.…”

Spray coating vs. immersion for self-assembly of gemini perfluorinated phosphonic acids on indium tin oxide

“…Perfluorinated PA SAMs have been previously studied on various surfaces, such as Mica [41], Mg [18], ZnO [22], [42] and ITO [23]. On ZnO, these films were shown to remain strongly bonded on the surfaces after sonication and after two years [42].…”