# Titania-Supported Photocatalytic Coatings of Cu2O Nanoparticles Synthesized via Heterogeneous Nucleation

## TL;DR

Researchers developed a method to create photocatalytic coatings using Cu2O nanoparticles on TiO2, which can degrade pollutants under visible light.

## Contribution

A one-step heterogeneous nucleation method to deposit Cu2O nanoparticles on TiO2 coatings, enhancing visible light photoactivity.

## Key findings

- Cu2O nanoparticles with oblate spheroidal shape and cubic crystal structure formed on TiO2 surfaces.
- Photoactivity of TiO2/Cu2O coatings was significant under UV and visible light for dye degradation.
- Surface coverage of Cu2O could be controlled via reaction time, enhancing visible light performance.

## Abstract

Mesoporous TiO2 sol–gel coatings with
a thickness
of 122 nm and a porosity of 49% were prepared by dip-coating, followed
by Cu2O nanoparticle deposition onto the surface using
a simple, one-step method: the TiO2 coating was immersed
in the reaction mixture and Cu2O particles formed on the
surface in a heterogeneous nucleation process. The crystallinity,
size, shape, and structure of the samples were characterized by X-ray
diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy,
atomic force microscopy, and scanning electron microscopy. Optical
properties, layer thickness, and porosity were determined by UV–vis
spectroscopy and spectroscopic ellipsometry. Cu2O nanoparticles
with an oblate spheroidal shape and cubic crystal structure formed
on the surface, with an average particle size of 326 nm, and the surface
coverage could be controlled by the reaction time. Photoactivity of
the TiO2/Cu2O coatings was studied in dye photodegradation
tests under UV and visible light, using methyl orange dye as a model
pollutant. The samples showed significant photoactivity; the amount
of Cu2O particles and their surface coverage on titania
played an important role. High surface coverage could be achieved
in a simple one-step deposition process using heterogeneous nucleation,
resulting in enhanced photoactivity under visible light, making this
method suitable to produce photoactive coatings for a variety of applications,
such as air and water purification.