Hydrothermal Synthesis of Layered Titanium Phosphate Ti2O2H(PO4)[(NH4)2PO4]2 and Its Potential Application in Cosmetics

Irina Kolesnik,Anatoly Arkhipin,Daniil Kozlov,Andrey Aslandukov

doi:10.3390/cryst9070332

Abstract

Titanium phosphates were recently revealed as promising cosmetic pigments; however, their photocatalytic activity and sun protective factor (SPF) levels have not been investigated in detail. In this study, we used hydrothermal conditions to prepare nanocrystalline anatase, brookite, and layered titanium phosphate using the titanium lactate complex, NH4H2PO4, and urea as precursors. The samples were characterized by powder X-ray diffraction (XRD) in addition to Raman spectroscopy, transmission and scanning electron microscopy (TEM, SEM), energy-dispersive X-ray spectroscopy (EDX), and UV-Vis spectroscopy. Furthermore, the photocatalytic activity, sun protective factor, and moisture retention ability were determined for the samples. Brookite exhibited the highest SPF value and anatase the lowest, while Ti2O2H(PO4)[(NH4)2PO4]2 displayed highly promising UV protection and moisture retention properties and, therefore, represents a polyfunctional pigment that is particularly well suited for cosmetic applications.

Highlights

Titanium oxide has been widely used as a cosmetic pigment and physical UV-filter for more than 40 years [1]
reactive oxygen species (ROS) can damage the organic components of cosmetic products and the skin sebum, both of which contribute to irritating inflammatory reactions on the skin surface [6,7]
Photocatalytic activity may be suppressed by doping the titanium oxide with metal ions [9,10,11] or modifying its surface composition [12,13,14]

Summary

Introduction

Titanium oxide has been widely used as a cosmetic pigment and physical UV-filter for more than 40 years [1]. Some titanium oxide samples, as well as related materials, exhibit photocatalytic activity that leads to reactive oxygen species (ROS) formation [2,3,4,5]. There are several approaches to suppressing the photocatalytic reactions on the surface of titania, including using amorphous titanium oxide, which has less photocatalytic activity than the crystalline phases [8]. Photocatalytic activity may be suppressed by doping the titanium oxide with metal ions [9,10,11] or modifying its surface composition [12,13,14]. Matsukura and Onoda showed that phosphate modification leads to photocatalytic activity suppression in TiO2 -containing pigments [12]

Methods

Results

Conclusion