Photocatalytic water splitting ability of Fe/MgO-rGO nanocomposites towards hydrogen evolution

TL;DR

This study demonstrates that Fe/MgO-rGO nanocomposites, especially when thermally treated at 500°C in argon, significantly enhance photocatalytic water splitting and dye degradation, offering a promising approach for hydrogen fuel production.

Contribution

The paper introduces a facile hydrothermal synthesis method for Fe/MgO-rGO nanocomposites and shows their superior photocatalytic performance after inert atmosphere heat treatment.

Findings

Fe/MgO-rGO(500) nanocomposite achieved 86% dye degradation.

The nanocomposite generated four times more H₂ than P25 titania.

Heat treatment improves morphological and surface properties.

Abstract

Photocatalytic water splitting has greatly stimulated as an ideal technique for producing hydrogen (H$_{2}$) fuel by employing two renewable sources, i.e., water and solar energy. Here, we have adopted a facile hydrothermal approach for the successful synthesis of reduced graphene oxide (rGO) incorporated Fe/MgO nanocomposites followed by thermal treatment at inert atmosphere to investigate their ability for photodegradation and photocatalytic hydrogen evolution via water splitting. Transmission Electron Microscopy images of Fe/MgO-rGO nanocomposite ensured the distribution of Fe/MgO nanoparticles throughout rGO sheets. Notably, all rGO supported nanocomposites, especially the one, thermally treated at 500 $^{o}$C at Argon (Ar) atmosphere has demonstrated significantly higher photocatalytic efficiency towards the photodegradation of a toxic textile dye, rhodamine B, than pristine MgO and commercially available Degussa P25 titania nanoparticles as well as other composites. Under solar irradiation, Fe/MgO-rGO(500) nanocomposite exhibited 86% degradation of rhodamine B dye and generated almost four times higher H$_{2}$ via photocatalytic water splitting compared to commercially available P25 titania nanoparticles. This promising photocatalytic ability of the Fe/MgO-rGO(500) nanocomposite can be attributed to the improved morphological and surface features due to heat treatment at inert atmosphere as well as escalated charge carrier separation with increased light absorption capacity imputed to rGO incorporation.