Chalcogen composition driven enhancement of catalytic efficiency in zirconium based monolayers: insight from reaction coordinate mapping

Abstract

The demand for an electrochemical water-splitting mechanism is on the rise due to the growing need for green and renewable energy conversion. However, the development of efficient electrocatalysts for this mechanism remains a major challenge. To address this, we have conducted a study using density functional theory (DFT) to investigate the catalytic activities of ZrS₂, ZrSe₂, and ZrTe₂ layered structures for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). We have also looked into the effect of non-metal (C, N, and P) functionalization on these catalytic activities. We have systematically represented the free energy diagram of HER, OER, and ORR mechanisms for all pristine and functionalized cases. Additionally, we have also investigated the electronic properties and d-band center for functionalized cases and found an interesting connection with the catalytic activities. Our findings show that pristine ZrS₂ emerged as the most efficient HER and OER catalyst among all pristine monolayers, while in the case of functionalization, the enhancement in HER activity comes after the doping of a single phosphorus atom for ZrS₂ and ZrSe₂ monolayers and a single nitrogen atom for the pristine ZrTe₂ monolayer, which are identified as the best candidates for the HER and OER mechanisms. This analysis provides valuable insights for designing cost-effective and efficient 2D electrocatalysts for HER, OER, and ORR catalytic activities in other types of layered structures such as TMDCs.