# Influence of C$_{6}$H$_{4}$(OH)$_{2}$ isomers on water disinfection by photocatalysis: a computational study

## TL;DR

This study computationally investigates how different C6H4(OH)2 isomers affect water disinfection via photocatalysis with TiO2, highlighting the role of their optical properties in bacterial inactivation.

## Contribution

It provides a theoretical analysis correlating isomer optical properties and adsorption energies with photocatalytic disinfection efficiency, complementing previous experimental work.

## Key findings

- Catechol shows the highest adsorption on TiO2.
- All isomers absorb UV light, with specific energies: resorcinol 3.42 eV, catechol 4.44 eV, hydroquinone 4.49 eV.
- Optical properties influence the inactivation of E. coli in photocatalytic water disinfection.

## Abstract

Solar disinfection by photocatalysis is one of the promising methods used for drinking water disinfection. It leads to the destruction of bacteria like $Escherichia$ $Coli$ ($E.$ $Coli$). In this paper, we compare our theoretical results with experimental ones done previously by A.G. Rinc\'on and his colleagues concerning the order of decay of C$_{6}$H$_{4}$(OH)$_{2}$ isomers in the presence of titanium dioxide TiO$_{2}$, and show the influence of optical properties of those molecules on $E.$ $Coli$ inactivation. According to the adsorption energy parameter, we find that catechol has the highest adsorption degree on titanium dioxide, followed by resorcinol, and finally hydroquinone. Three dihydroxybenzene isomers absorb photons belonging to ultraviolet (UV) range. The lowest absorption energies of resorcinol, catechol and hydroquinone are respectively 3.42, 4.44 and 4.49 eV.