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

Omeshwari Yadorao Bisen; Shahan Atif; Ambresh Mallya; Karuna Kar Nanda

doi:10.1021/acsami.1c11300

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

ACS Appl Mater Interfaces. 2022 Feb 2;14(4):5134-5148. doi: 10.1021/acsami.1c11300. Epub 2022 Jan 20.

Authors

Omeshwari Yadorao Bisen¹, Shahan Atif¹, Ambresh Mallya², Karuna Kar Nanda^{1

3}

Affiliations

¹ Materials Research Centre, Indian Institute of Science, Bangalore 560012, India.
² Centre for Nano Science and Engineering, Indian Institute of Science, Bangalore 560012, India.
³ Institute of Physics, P.O. Sainik School, Bhubaneswar 751005, India.

PMID: 35049270
DOI: 10.1021/acsami.1c11300

Abstract

Here, we report on a universal carbothermal reduction strategy for the synthesis of well-dispersed WS₂ nanoparticles (∼1.7 nm) supported on a N-doped carbon (N_xC) nanostructure and the electrocatalytic activity toward oxygen reduction reaction (ORR). Bulk WS₂ powder (2 μm) is the source for WS₂ nanoparticles, and dicyandiamide is the source for N_xC and carbothermal reduction. Interestingly, WS₂/N_xC serves the purpose of innovative and robust active sites for ORR through an efficient four-electron transfer process with excellent durability. Remarkably, WS₂/N_xC suppresses the peroxide generation due to the dominating inner-sphere electron transfer mechanism where the direct adsorption of the desolvated O₂ molecule on the electroactive centers takes place. The mass activity (at 0.4 and 0.85 V vs RHE) of WS₂/N_xC 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 WS₂/N_xC 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_xC such as MoS₂/N_xC, MoSe₂/N_xC, and WSe₂/N_xC.

Keywords: WS2 nanoparticles; carbothermal reduction; electrochemical oxygen sensing; highly durable catalyst; oxygen reduction reaction; tungsten disulfide.