Enhanced photocatalytic activities of three-dimensional graphene-based aerogel embedding TiO2 nanoparticles and loading MoS2 nanosheets as Co-catalyst

Abstract

A novel graphene-based three-dimensional (3D) aerogel embedded with two types of functional nanomaterials had been prepared by a facile one-pot hydrothermal process. During the hydrothermal reaction, graphene, TiO2 nanoparticles and MoS2 nanosheets were self-assembled into the 3D interconnected networks aerogel, where the uniformly dispersed TiO2 nanoparticles were densely anchored onto the graphene nanosheets and decorated with the ultrathin MoS2 nanosheets. The UV–vis DRS and PL spectra measurement shows that the MoS2/P25/graphene aerogel exhibits enhanced light absorption and efficient charge separation properties. As a new photocatalyst, the photocatalytic activity was evaluated by photoelectrochemical test and photodegradation methyl orange (MO) under UV irradiation, an improvement of photocurrent was observed, as 6 times higher for MoS2/P25/graphene aerogel (37.45 mA/cm2) than pure P25 at +0.6 V, and the fastest photodegradation of MoS2/P25/graphene aerogel was found within 15 min. The improved photocatalytic activity is attributed to the porous structure, good electrical conductivity and the maximization of accessible sites of the unique 3D graphene aerogel, the increasing active adsorption sites and photocatalytic reaction centers for the introduction of MoS2 nanosheets, and the positive synergetic effect between the three components in this hybrid. This work demonstrates that the as-prepared MoS2/P25/graphene aerogel may have a great potential application in photoelectrochemical hydrogen production and pollution removal.