# A Study on the UV Degradation Performance of Rhodamine B by Zn-TiO2 Photocatalysts and Cement Mortar-Based Zn-TiO2 Composites

## TL;DR

This study shows that Zn-TiO2 photocatalysts improve the breakdown of Rhodamine B dye and can be used in green building materials for pollution control.

## Contribution

The study introduces Zn-TiO2/ACM composites as novel green building materials with enhanced photocatalytic performance and stability.

## Key findings

- Zn-TiO2 synthesized at 120 °C showed 26% better degradation of Rhodamine B than pure TiO2.
- Zn-TiO2/ACM composites demonstrated superior photocatalytic activity and stability compared to conventional materials.
- Characterization techniques confirmed structural and compositional factors contributing to enhanced performance.

## Abstract

Zn-TiO2 composites were synthesized via a hydrothermal method, and their photocatalytic performance was optimized using an orthogonal design. Among the factors of hydrothermal temperature, reaction time, and Ti/Zn molar ratio, hydrothermal temperature showed the most significant influence on the photocatalytic performance of Zn-TiO2. The Zn-TiO2 obtained under the optimal conditions (120 °C, 10 h, and a Ti/Zn molar ratio of 100:5) exhibited the best photocatalytic performance, with a 26% improvement in the photocatalytic degradation efficiency of Rhodamine B (RB) compared to pure TiO2 under identical conditions. The composition, morphology, and structure of the Zn-TiO2 photocatalysts were characterized by XRD, SEM-EDS, N2 adsorption–desorption, and XPS, thereby enabling analysis of the mechanism for the enhancement of its photocatalytic performance. In this work, air-entrained composite mortar (ACM) with a double-layer structure was designed as a contrast to conventional cement mortar (CM). Novel green building materials with pollutant-degradation capability were developed by loading Zn-TiO2 and TiO2 photocatalysts onto these different mortar surfaces. Photocatalytic tests and cyclic aging experiments demonstrated that the Zn-TiO2/ACM achieved the superior degradation effect on the RB solution and maintained good catalytic stability. These findings suggest broad application prospects in the field of green building materials.