# Effect of nano-TiO2 size and utilization ratio on the performance of photocatalytic concretes; self-cleaning, fresh, and hardened state properties

## TL;DR

This study explores how different sizes and amounts of nano-TiO2 affect concrete properties and its ability to clean pollutants from water.

## Contribution

The novel contribution is evaluating the impact of nano-TiO2 particle size and ratio on both photocatalytic performance and concrete properties.

## Key findings

- Photocatalytic performance was better with 38 nm nano-TiO2 compared to 28 nm.
- Lower particle size (28 nm) improved compressive and flexural strengths of concrete.
- Adding nano-TiO2 reduced the flow performance of concrete mixtures.

## Abstract

In this study, photocatalysis technology was used to reduce water pollution. Decolorization of Reactive Black 5 using nano-TiO2 (NT) as a photocatalyst was investigated by adsorption and degradation experiments. Effects of NT particle size and utilization ratio on the time-dependent flow performance, compressive-flexural strength, and Bohme abrasion resistance of cementitious systems were investigated. In addition to the NT-free control mixture, a total of six photocatalytic self-cleaning mortar mixtures (PSCM) were prepared using NT in two different particle sizes (28 and 38 nm) and three different ratios (0.5%, 1%, and 1.5%). The PSCM sample containing 38 nm NT exhibited superior performance in terms of photocatalytic properties compared to the 28 nm state. It was observed that the flow performance of PSCM mixtures with NT substitution is adversely affected regardless of the NT type. Mixtures containing NT with a lower particle size (28 nm) had higher compressive and flexural strengths.