Preparation of Nanowire like WSe2-Graphene Nanocomposite for Photocatalytic Reduction of CO2 into CH3OH with the Presence of Sacrificial Agents

Asghar Ali,Won-Chun Oh

doi:10.1038/s41598-017-02075-7

Abstract

A nanowire-like WSe2-graphene catalyst was prepared via ultra-sonication and was tested in terms of the photocatalytic reduction of CO2 into CH3OH under irradiation with UV/visible light. The prepared nano-composite was further characterized via XRD, SEM, TEM, Raman and XPS. The photocurrent analysis was further tested for its photocatalytic reduction of CO2 using gas chromatography (GCMS-QP2010 SE). To further improve the the photo-catalytic efficiency, a sacrificial agent (Na2S/Na2SO3) was added to the WSe2-graphene nanocomposite and was found to improve the photo-catalytic efficiency, with the methanol yield reaching 5.0278 µmol g−1h−1. Our present work provides a convenient way to prepare nanomaterials various morphologies that have future applications for environmental remediation.

Highlights

The increase in the amount of the CO2 emissions in the environment has reached an alarming level, greatly contributing to global warming[1], and in the last few decades, the shortage of fossil fuel resources has resulted in an increased demand for energy production from different sources, including photovoltaic and photocatalytic H2 production
Graphene coupled with transition metal dichalcogenides (TMDC) (WSe2) was reported for the hydrogen evolution reaction (HER)[28], high-performance oxygen reduction reaction (ORR)[29] and in a superconductor[30]
The prepared samples (WSe2-graphene) were used for CO2 reduction, and the results exhibit a high efficiency for photo catalytic CO2 conversion under UV and visible light irradiation

Summary

Introduction

The increase in the amount of the CO2 emissions in the environment has reached an alarming level, greatly contributing to global warming[1], and in the last few decades, the shortage of fossil fuel resources has resulted in an increased demand for energy production from different sources, including photovoltaic and photocatalytic H2 production. Due to the wide band gap energy, most materials are unable to absorb visible light, and on the other hand, small band gap semiconductors exhibit a fast recombination phenomenon To overcome this and to find an achievable process, highly efficient, low cost transition metal dichalcogenides (TMDC) have been investigated[12,13,14,15]. WSe2 is a layered semiconductor with a small band gap of approximately 1.6 eV18 It has unique electrical transport performance, and its use was recently reported in many advanced energy storage applications, such as in superconductors[19], lithium ion batteries[20], photodetectors[21], and photocatalytic hydrogen production[22] in solar cells. The prepared samples (WSe2-graphene) were used for CO2 reduction, and the results exhibit a high efficiency for photo catalytic CO2 conversion under UV and visible light irradiation

Methods

Results

Conclusion