Enhanced Solar Light Photocatalytic Activity of Ag Doped TiO2–Ag3PO4 Composites

Abdessalem Hamrouni,Riccardo Ceccato,Hanen Azzouzi,Ali Rayes,Leonardo Palmisano,Francesco Parrino

doi:10.3390/nano10040795

Abdessalem Hamrouni, Riccardo Ceccato + Show 4 more

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https://doi.org/10.3390/nano10040795

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Abstract

Composites comprised of Ag3PO4 and bare TiO2 (TiO2@Ag3PO4) or silver doped TiO2 (Ag@TiO2–Ag3PO4) have been synthesized by coupling sol–gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis. The optoelectronic and structural features of the samples have been related to their photocatalytic activity for the degradation of 4–nitrophenol under solar and UV light irradiation. Coupling Ag3PO4 with silver doped TiO2 mitigates photocorrosion of the Ag3PO4 counterpart, and remarkably improves the photocatalytic activity under solar light irradiation with respect to the components, to the TiO2–Ag3PO4 sample, and to the benchmark TiO2 Evonik P25. These features open the route to future applications of this material in the field of environmental remediation.

Highlights

IntroductionThe surface of Earth receives 3850000 EJ of solar energy. only 0.014% of it is currently exploited to cover the energy demand, and to face environmental issues [1]
Each year, the surface of Earth receives 3850000 EJ of solar energy
All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis

Summary

Introduction

The surface of Earth receives 3850000 EJ of solar energy. only 0.014% of it is currently exploited to cover the energy demand, and to face environmental issues [1]. Efficient solar light conversion is one of the hot topics of our society, which is aware of the need to develop and actuate sustainable processes to mitigate the dramatic climate changes and environmental disaster we are the witness of in the last years. The unique properties of visible light active semiconductors allow one to use them to convert solar energy into photogenerated charges, which, in turn, enable electricity generation or trigger useful chemical reactions. In this way, it is possible to mimic nature by storing solar energy in chemical bonds, by producing high value-added chemical compounds in a “green” way, or by removing hazardous compounds through their photoinduced mineralization. In order to overcome this limitation, TiO2 has been variously modified to extend its light absorption range toward the visible light region [2]

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