Carbon‐Quantum‐Dots‐Loaded Ruthenium Nanoparticles as an Efficient Electrocatalyst for Hydrogen Production in Alkaline Media

Abstract

Highly active, stable, and cheap Pt-free catalysts for the hydrogen evolution reaction (HER) are facing increasing demand as a result of their potential use in future energy-conversion systems. However, the development of HER electrocatalysts with Pt-like or even superior activity, in particular ones that can function under alkaline conditions, remains a significant challenge. Here, the synthesis of a novel carbon-loaded ruthenium nanoparticle electrocatalyst (Ru@CQDs) for the HER, using carbon quantum dots (CQDs), is reported. Electrochemical tests reveal that, even under extremely alkaline conditions (1 m KOH), the as-formed Ru@CQDs exhibits excellent catalytic behavior with an onset overpotential of 0 mV, a Tafel slope of 47 mV decade , and good durability. Most importantly, it only requires an overpotential of 10 mV to achieve the current density of 10 mA cm . Such catalytic characteristics are superior to the current commercial Pt/C and most noble metals, non-noble metals, and nonmetallic catalysts under basic conditions. These findings open a new field for the application of CQDs and add to the growing family of metal@CQDs with high HER performance.

Biomass‐Derived Carbon Dots and Their Applications

“…Characterization of BCDs is essential for attaining a better understanding of the mechanisms associated with the unique physical properties of these nanoparticles. Figure a,b shows that a TEM image of BCDs shows that they have good dispersion. Most BCDs have a particle size/diameter of <10 nm, but there are a few exceptions, such as the 19 nm measured for BCDs prepared from silkworm cocoons and the 21.5 nm for BCDs from goose feathers .…”

“…In addition to vegetables and fruits, there are a lot of biomass that can be used as a carbon source to prepare BCDs, for example, grass, ginkgo leaves, bamboo leaves and other plants, black tea, soy milk, and other beverages. BCDs prepared with these carbon sources have a good dispersion, and the size distribution is relatively uniform.…”

“…Its quantum yield is 7.1%. Recently, Li et al . reported that BCDs were prepared from ginkgo leaves by hydrothermal treatment at 200 °C for 8 h. The prepared BCDs are well distributed and have a diameter of approximately 4.11 nm and a fluorescence QY of 21.7%.…”

“…Compared with bamboo leaves, the quantum yield of BCDs prepared from ginkgo biloba leaves as carbon source has been greatly improved. In plants, besides bamboo leaves and ginkgo leaves, aloe, lignin biomass, and willow bark are also used as biomass carbon sources to prepare BCDs. The size distribution of BCDs was uniform, and the quantum yield of BCDs prepared with lignin biomass as carbon source was up to 21%.…”

Single‐Atom Ru Doping Induced Phase Transition of MoS2 and S Vacancy for Hydrogen Evolution Reaction

“…Recently, investigators discovered that Ru‐based catalysts can efficiently catalyze HER. Although Ru‐based nanoparticle, cluster and alloy catalysts have been reported to exhibit excellent activity similar to Pt, they do not show the maximum atomic efficiency of Ru…”