Atomistic insights into uptake of hydrogen peroxide by TiO2 particles as a function of humidity

In this work, a multiscale and comprehensive study for the heterogeneous interaction between H2O2 and TiO2 particles has been explored. It is found that the H2O2 and H2O adsorption on the TiO2 surface mainly depends on the weaker interaction between surface Ti atom and O atom in H2O2 and H2O. The calculation results indicated that the adsorption energy was dominated by electrostatic effect. Besides, the adsorption energy of TiO2-H2O complexes is smaller than that of TiO2-H2O2 ones. We also found that the interaction of H2O2 and H2O on TiO2 particles is displayed by molecular adsorption and dissociation. It will modify the particle surface and results in the formation of Ti-OH. The reaction sites came from the Ti and O atom on TiO2 particle surface. After the reaction, the surface Ti atoms were oxidized. Moreover, H2O2 uptake on TiO2 surface was suppressed with the increase of humidity likely by H2O could competition for TiO2 surface sites. Based on the findings report here, the heterogeneous reaction between H2O2 and TiO2 particles was investigated at atomic-level, which can be help for understanding the effect of modified mineral dust on human health. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this work, a multiscale and comprehensive study was conducted to investigate the heterogeneous interaction between H2O2 and TiO2 particles. The adsorption of H2O2 and H2O on the TiO2 surface was found to be primarily determined by the weaker interaction between Ti and O atoms. The adsorption energy was dominated by electrostatic effect, and the adsorption energy of TiO2-H2O complexes was lower than that of TiO2-H2O2 ones. H2O2 and H2O interacted with TiO2 particles through molecular adsorption and dissociation, resulting in surface modification and Ti-OH formation. The uptake of H2O2 on TiO2 surface was suppressed with increasing humidity, possibly due to competition for surface sites with H2O.