Self-Assembled TMD Nanoparticles on N-Doped Carbon Nanostructures for Oxygen Reduction Reaction and Electrochemical Oxygen Sensing Thereof

Abstract

Here, we report on a universal carbothermal reduction strategy for the synthesis of well-dispersed WS 2 nanoparticles (∼1.7 nm) supported on a N-doped carbon (N x C) nanostructure and the electrocatalytic activity toward oxygen reduction reaction (ORR). Bulk WS 2 powder (2 μm) is the source for WS 2 nanoparticles, and dicyandiamide is the source for N x C and carbothermal reduction. Interestingly, WS 2 /N x C serves the purpose of innovative and robust active sites for ORR through an efficient four-electron transfer process with excellent durability. Remarkably, WS 2 /N x C suppresses the peroxide generation due to the dominating inner-sphere electron transfer mechanism where the direct adsorption of the desolvated O 2 molecule on the electroactive centers takes place. The mass activity (at 0.4 and 0.85 V vs RHE) of WS 2 /N x C outperforms the previously reported transition metal based electrocatalysts. The study further establishes a correlation between the work function and the ORR activity. We have also exploited WS 2 /N x C for electrochemical oxygen sensing, and there exists a direct correlation between oxygen sensing and ORR as both depend on the oxygen adsorption ability. Finally, the carbothermal reduction strategy has been extended for the synthesis of other TMDs/N x C such as MoS 2 /N x C, MoSe 2 /N x C, and WSe 2 /N x C.

Insights into the electrocatalytic behavior of nitrogen and sulfur co-doped carbon nanotubes toward oxygen reduction reaction in alkaline media

“…where C dl is the double-layer capacitance and C s is the specific capacitance of the material which is reported as 0.040mF/cm 2 [32,33].…”

Electrostatic Interaction in Amino Protonated Chitosan–Metal Complex Anion Hydrogels: A Simple Approach to Porous Metal Carbides/N-Doped Carbon Aerogels for Energy Conversion

“…Based on the exploration of new sustainable energy systems, electrochemical energy conversion technology has been developed rapidly. Electrocatalysts play a key role in energy conversion technology because they improve the rate and efficiency of the chemical conversion involved. − However, commercial electrocatalysts are largely dependent on precious metals, such as Pt, Pd, Ru, Rh, and so forth. − For example, platinum (Pt)- and iridium (Ir)/ruthenium (Ru)-based catalysts are deemed to be the best catalysts for oxygen reduction reaction (ORR), but their high cost and scarcity limit the development and application of electrochemical energy conversion technology. − With the development of technology and the demand for high performance of electrocatalysts, the low-cost transition metal-based materials with efficient electrocatalystic activities are widely considerable. , …”

Tailoring charge reconfiguration in dodecahedral Co2P@carbon nanohybrids by triple-doping engineering for promoted reversible oxygen catalysis

“…3d and the ESI Section†), demonstrating a typical four-electron reaction mechanism towards the ORR. 68,69 Expectedly, this champion catalyst also affords a decent value of j L and the current measured from the Pt ring corresponding to the contribution of hydrogen peroxide production is nearly ignorable according to eqn (3) (see the ESI Section†), thereby indicating that the major product in the ORR process is OH − species. The tolerance of the Fe-Co 2 P@NPDC catalyst to the poisoning effect of fuel molecules was also studied.…”