# Aluminum nanoparticle enhanced TiO2 photocatalysis of organic pollutants under solar and UV-B irradiation

## TL;DR

A new sustainable water treatment method uses aluminum nanoparticles with titanium dioxide to efficiently break down pollutants using sunlight.

## Contribution

A low-cost plasmonic-photocatalytic heterostructure using Al nanoparticles with TiO2 is introduced for efficient organic pollutant degradation under solar light.

## Key findings

- Al/TiO2 heterostructures enhance TiO2 photocatalysis through improved light absorption and plasmon resonance.
- Cysteine-modified Al/TiO2 degrades the dye amaranth 60% faster than P25 TiO2 and remains stable over multiple cycles.

## Abstract

Photocatalytic water treatment offers a sustainable method for removing organic micropollutants but is often limited by low efficiency and complexity. We report a plasmonic-photocatalytic heterostructure combining aluminum (Al) nanoparticles with titanium dioxide (TiO2) for contaminant degradation under solar light without external oxidants or pH adjustment. Using an organic colloidal Al nanoparticle suspension, this approach enhances TiO2 photocatalysis through improved light absorption, plasmon resonance, and contaminant adsorption. The low-cost Al/TiO2 heterostructure provides light-harvesting benefits comparable to other noble metal heterostructures (Au/TiO2 and Ag/TiO2), offering a sustainable alternative. Synthesized via an organic solvent method and ligand modification, the heterostructures were characterized for charge, size, bandgap, and photocatalytic efficiency. A cysteine-modified Al/TiO2 showed the best performance, degrading the dye amaranth 60% faster than P25 TiO2 and remaining stable over repeated cycles, underscoring its potential for integration into small-scale, solar-driven water treatment systems.