Preparation of Pt nanoparticles deposited on molybdenum disulfide-reduced graphene oxide

Preparation of Pt nanoparticles deposited on molybdenum disulfide-reduced graphene oxide

Pt nanoparticles are widely used in various applications, ranging from fuel cells to catalysis. In recent years, there has been an increasing interest in developing efficient and cost-effective methods for the synthesis of Pt nanoparticles with controlled size and morphology. One such method involves the deposition of Pt nanoparticles onto a support material, such as molybdenum disulfide-reduced graphene oxide.

Molybdenum disulfide-reduced graphene oxide (MoS2-rGO) is a hybrid material that combines the excellent electrical conductivity of reduced graphene oxide (rGO) with the high surface area and catalytic activity of molybdenum disulfide (MoS2). This makes it an ideal support material for the deposition of Pt nanoparticles. The synthesis of Pt nanoparticles on MoS2-rGO can be achieved through a two-step process.

The first step involves the synthesis of MoS2-rGO by a hydrothermal or solvothermal method. In a typical hydrothermal method, graphene oxide and ammonium molybdate are dispersed in water, followed by the addition of thiourea as a reducing agent. The mixture is then heated in an autoclave at a high temperature and pressure, resulting in the reduction of graphene oxide and the formation of MoS2-rGO sheets. The resulting MoS2-rGO sheets exhibit a highly porous structure with a large surface area, providing ample sites for the deposition of Pt nanoparticles.

In the second step, Pt nanoparticles are deposited onto the MoS2-rGO sheets through a deposition-reduction process. A Pt precursor, such as PtCl4, is dissolved in a solvent, such as ethanol, and mixed with the MoS2-rGO sheets. The mixture is then stirred under reflux conditions, allowing the Pt precursor to adsorb onto the MoS2-rGO sheets. Finally, a reducing agent, such as sodium borohydride, is added to the mixture, resulting in the reduction of the Pt precursor and the formation of Pt nanoparticles on the MoS2-rGO sheets.

The size and morphology of the Pt nanoparticles can be controlled by adjusting the concentration of the Pt precursor, the reaction temperature, and the reaction time. For example, increasing the concentration of the Pt precursor or the reaction temperature can lead to the formation of larger Pt nanoparticles. On the other hand, increasing the reaction time can promote the formation of more uniform Pt nanoparticles with a narrower size distribution.

The synthesized Pt nanoparticles deposited on MoS2-rGO exhibit excellent catalytic activity and stability. The high surface area and electronic conductivity of MoS2-rGO facilitate the diffusion of reactants to the Pt nanoparticles, while also providing efficient electron transfer pathways. As a result, the Pt nanoparticles supported on MoS2-rGO demonstrate enhanced catalytic performance for various reactions, including oxygen reduction reaction in fuel cells and hydrogen evolution reaction in water splitting.

In conclusion, the preparation of Pt nanoparticles deposited on molybdenum disulfide-reduced graphene oxide offers a promising approach for the synthesis of Pt-based catalysts with desirable properties. The hybrid material of MoS2-rGO provides a favorable support for the deposition of Pt nanoparticles, leading to improved catalytic activity and stability. With further optimization and development, this method has the potential to contribute to the advancement of various applications in the fields of energy conversion and catalysis.