Mo₂C-Based Electrocatalyst with Biomass-Derived Sulfur and Nitrogen Co-Doped Carbon as a Matrix for Hydrogen Evolution and Organic Pollutant Removal

Abstract

A Mo2C based electrocatalyst (Mo2C@SNC) was successfully synthesized with sulfur and nitrogen codoped carbon (SNC) as the matrix, which was derived from the shells of sunflower seeds. In the Mo2C/SNC, Mo2C particles that range in size from approximately 5 to 8 nm are evenly distributed in the sulfur and nitrogen codoped carbon matrix. Moreover, Mo2C/SNC has a large specific surface area with a mesoporous character. These particular structural features result in Mo2C@SNC having good electrocatalytic activity for hydrogen evolution reaction (HERs). To obtain 10 mA·cm–2 current in 1 M KOH, Mo2C@SNC only needs an overpotential as low as 60 mV. Mo2C@SNC also has outstanding durability and remains stable for over 2000 cycles. During a HER process, its hydrogen evolution rate reaches 90.2 μmol·h–1, with faradaic efficiency reaching almost 100%. Under acidic conditions, the advantages of Mo2C@SNC are obvious. In addition to electrocatalytic hydrogen evolution, Mo2C@SNC exhibits striking catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol. The conversion efficiency reaches almost 100% in 6 min with only a small amount of Mo2C@SNC used for the catalyst. In addition to 4-nitrophenol, Mo2C@SNC also affects methylene blue (MB), a common organic dye. We expect that Mo2C@SNC will become a new resource for H2 energy and will be a prospective material for water purification.