Novel Mixed-Dimensional Photocatalysts Based on 3D Graphene Aerogel Embedded with TiO₂/MoS₂ Hybrid

Abstract

The ternary mixed-dimensional TiO2/MoS2/graphene-aerogel, zero-dimensional TiO2 nanoparticles loaded on two-dimensional MoS2 nanosheets, and TiO2/MoS2 hybrid embedded into the three-dimensional (3D) graphene aerogel, was successfully prepared by self-assembly hydrothermal reduction process. The macroscopic appearance of TiO2/MoS2/graphene-aerogel is recorded using a digital camera. The microstructure of the TiO2/MoS2/graphene-aerogel with three-dimensional interconnected porous network structure was characterized by scanning electron microscope and transmission electron microscope. UV–vis absorption spectra tests show that TiO2/MoS2/graphene-aerogel possesses enhanced light absorption properties. The photocatalytic performance of TiO2/MoS2/graphene-aerogel was tested by the photoelectrochemical system, and it is verified that the photocurrent density of the as-prepared TiO2/MoS2/graphene-aerogel is greatly improved to 105 μA/cm2 at a voltage of 0.6 V, which is approximately 10 times than of sole TiO2. The improved photocatalytic activity is due to the enormous specific surface area caused by the multiaperture structure of the unique 3D graphene aerogel, maximized reactive sites, good conductivity, and positive coupling effect with TiO2/MoS2 heterojunction. This study indicates that TiO2/MoS2/graphene-aerogel based photocatalysts have excellent potential for photocatalytic H2 production and photocatalytic degradation.