Visible Light Driven Photoanodes for Water Oxidation Based on Novel r-GO/β-Cu₂V₂O₇/TiO₂ Nanorods Composites.

Shuang Shuang,Leonardo Girardi,Zhengjun Zhang,Gaetano Granozzi,Carla Marega,Andrea Sartorel,Gian Rizzi

doi:10.3390/nano8070544

Shuang Shuang, Leonardo Girardi + Show 5 more

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https://doi.org/10.3390/nano8070544

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Journal: Nanomaterials	Publication Date: Jul 18, 2018
Citations: 25	License type: CC BY 4.0

Affiliation: University of Padua, Tsinghua University

Abstract

This paper describes the preparation and the photoelectrochemical performances of visible light driven photoanodes based on novel r-GO/β-Cu2V2O7/TiO2 nanorods/composites. β-Cu2V2O7 was deposited on both fluorine doped tin oxide (FTO) and TiO2 nanorods (NRs)/FTO by a fast and convenient Aerosol Assisted Spray Pyrolysis (AASP) procedure. Ethylenediamine (EN), ammonia and citric acid (CA) were tested as ligands for Cu2+ ions in the aerosol precursors solution. The best-performing deposits, in terms of photocurrent density, were obtained when NH3 was used as ligand. When β-Cu2V2O7 was deposited on the TiO2 NRs a good improvement in the durability of the photoanode was obtained, compared with pure β-Cu2V2O7 on FTO. A further remarkable improvement in durability and photocurrent density was obtained upon addition, by electrophoretic deposition, of reduced graphene oxide (r-GO) flakes on the β-Cu2V2O7/TiO2 composite material. The samples were characterized by X-ray Photoelectron Spectroscopy (XPS), Raman, High Resolution Transmission Electron Microscopy (HR-TEM), Scanning Electron Microscopy (SEM), Wide Angle X-ray Diffraction (WAXD) and UV–Vis spectroscopies. The photoelectrochemical (PEC) performances of β-Cu2V2O7 on FTO, β-Cu2V2O7/TiO2 and r-GO/β-Cu2V2O7/TiO2 were tested in visible light by linear voltammetry and Electrochemical Impedance Spectroscopy (EIS) measurements.

Highlights

The hydrogen economy is a new intriguing sustainable scenario, and it is expected that sooner or later it is going to replace the hydrocarbon economy [1]
We show here that graphene oxide (GO), deposited by electrophoretic deposition, can efficiently coat the surface of the β-Cu2V2O7/TiO2 nanostructures and, after a mild annealing, is transformed into reduced graphene oxide (r-GO) causing a remarkable enhancement of the photocurrent with increased durability
The PEC measurements on β-Cu2V2O7 films deposited on fluorine doped tin oxide (FTO) (β-Cu2V2O7) using different aerosol solutions are discussed later in the text, it is useful to anticipate that vanadates prepared using solution 1 (NH3) gave the best PEC results with respect to the other two solutions

Summary

Introduction

The hydrogen economy is a new intriguing sustainable scenario, and it is expected that sooner or later it is going to replace the hydrocarbon economy [1]. The intrinsic simplicity of PEC, which combines the light absorber and the energy converter into a single device capable to store solar energy into chemical bonds, is rather evident. For these reasons, numerous studies have been performed to fabricate semiconducting nanomaterials with enhanced PEC properties under visible light. Many efforts have been done on developing materials for photoanodes, where the kinetically hindered Oxygen Evolution Reaction (OER) is occurring Their final performance depends upon the electrocatalysts stability against oxidation [3] and on their intrinsic band energetics [4]

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