# Recyclable dye-sensitized TiO2 composite membranes with interfacial spectral complementarity for sustainable white-light-driven dye degradation

## TL;DR

Scientists created a recyclable membrane that efficiently breaks down dye pollutants using visible light, offering a sustainable solution for wastewater treatment.

## Contribution

A novel co-sensitized TiO2 photocatalyst embedded in PMMA fibers is developed for enhanced and recyclable dye degradation under visible light.

## Key findings

- The PMMA/CS-TiO2 membrane achieved a net methylene blue degradation efficiency of 58.12%.
- The membrane retained ∼80% efficiency after five cycles, showing excellent reusability.
- The enhanced performance is attributed to synergistic co-sensitization and efficient charge separation.

## Abstract

The efficient and low-energy treatment of dye wastewater remains a significant challenge. Herein, a novel co-sensitized TiO2 photocatalyst (CS-TiO2) was constructed by combining ruthenium-based dye N719 with a laboratory-synthesized organic dye RA, aiming to extend the visible-light absorption range. The CS-TiO2 was subsequently embedded into poly(methyl methacrylate) micro–nano fibers via centrifugal spinning, yielding easily recyclable photocatalytic membranes. After deducting the 30% self-degradation contribution of methylene blue arising from its intrinsic photosensitizing effect, the as-prepared PMMA/CS-TiO2 membrane achieved a net MB degradation efficiency of 58.12%—significantly superior to that of single-dye sensitized counterparts. This enhanced performance is ascribed to efficient charge separation and boosted production of dominant ·OH radicals enabled by the synergistic co-sensitization effect. Notably, the membrane retained ∼80% of its initial net degradation efficiency after five consecutive cycles, demonstrating excellent reusability and structural stability. This work offers a promising approach for constructing efficient, sustainable, and recyclable photocatalytic systems for dye wastewater remediation.

The efficient and low-energy treatment of dye wastewater remains a significant challenge.