# Preparation and Photocatalytic Performance Study of TiO2-TMP Composites Under Effect of Crystal Structure Modulation

## TL;DR

This study explores how modifying the crystal structure of titanium dioxide with a polymer improves its ability to break down pollutants under visible light.

## Contribution

The paper introduces a method to enhance photocatalytic activity by modulating TiO2 crystal forms and combining them with TMP polymers.

## Key findings

- TiO2 crystal form affects interface charge separation and transfer in TiO2-TMP composites.
- The 4T-TMP system achieved the highest methylene blue degradation rate under visible light.
- Crystal structure modulation and polymer interaction influence the built-in electric field and active sites.

## Abstract

Nano-titanium dioxide (TiO2) is currently the most widely studied photocatalyst. However, its rapid recombination of photogenerated carriers and narrow range of light absorption have limited its development. Crystal form regulation and polymer modification are important means for improving the photocatalytic activity of single-phase materials. In this paper, TiO2 materials of different crystal forms were prepared by changing the synthesis conditions, and they were compounded with trimesoyl chloride–melamine polymers (TMPs) by the hydrothermal synthesis method. Then, their photocatalytic performance was evaluated by degrading methylene blue (MB) under visible light. The mechanisms of influence of TiO2 crystal form on the photocatalytic activity of TiO2-TMP were explored by combining characterization and theoretical calculation. The results showed that the TiO2 crystal form, through interface interaction, the built-in electric field intensity of the heterojunction, and active sites, affected the interface charge separation and transfer, thereby influencing the photocatalytic activity of TiO2-TMP. In the 4T-TMP photocatalytic system, the degradation rate of MB was the highest. These studies provide theoretical support for understanding the structure–property relationship of the interfacial electronic coupling between TiO2 crystal forms and TMP, as well as for developing more efficient catalysts for pollutant degradation.