Researchers at Hanyang University, South Korea, have announced a significant advancement in the quest for cost-effective green hydrogen production. A team led by Professors Seunghyun Lee and Dun Chan Cha, both from Hanyang University's ERICA campus, has successfully developed a novel tunable boron-doped cobalt phosphide (CoP) nanosheet-based electrocatalyst.
Researchers at Hanyang University, South Korea, have announced a significant advancement in the quest for cost-effective green hydrogen production. A team led by Professors Seunghyun Lee and Dun Chan Cha, both from Hanyang University's ERICA campus, has successfully developed a novel tunable boron-doped cobalt phosphide (CoP) nanosheet-based electrocatalyst. This innovative material promises to dramatically reduce the prohibitive costs associated with electrochemical water-splitting, a crucial process for generating clean hydrogen.
Hydrogen, with its zero-carbon content and high energy density, is widely recognized as a pivotal clean energy source in the global effort to curb greenhouse gas emissions and combat climate change. However, the widespread adoption of hydrogen as a primary energy carrier has been hindered by the high production costs, largely due to the reliance on expensive and rare earth metal catalysts for the electrochemical water-splitting process. While transition metal phosphides (TMPs) have shown promise for the hydrogen evolution reaction (HER) side of this process, their poor performance in the oxygen evolution reaction (OER) has historically limited overall efficiency.
The Hanyang University team's breakthrough addresses this critical limitation. Their new electrocatalyst, developed using an ingenious strategy involving metal-organic frameworks (MOFs), offers a solution that is both highly efficient and significantly more affordable than conventional options. Professor Lee elaborated on the innovation, stating, "We have successfully developed cobalt phosphides-based nanomaterials by adjusting boron doping and phosphorus content using metal-organic frameworks. These materials have better performance and lower cost than conventional electrocatalysts, making them suitable for large-scale hydrogen production."
The researchers’ innovative approach involved leveraging cobalt (Co) based MOFs as precursors. As Cha explained, "MOFs are excellent precursors for designing and synthesizing nanomaterials with the required composition and structures." The process began by growing Co-MOFs on nickel foam (NF). This material then underwent a post-synthesis modification (PSM) reaction with sodium borohydride (NaBH4), leading to the crucial integration of boron. Finally, a phosphorization process, utilizing varying amounts of sodium hypophosphite (NaH2PO2), resulted in the creation of three distinct samples of the B-doped cobalt phosphide nanosheets (B-CoP@NC/NF).
Extensive experiments confirmed the exceptional properties of these new materials. All three samples showcased a large surface area and a mesoporous structure – key features that are instrumental in enhancing electrocatalytic activity. Consequently, they exhibited excellent performance in both the OER and HER. A notable demonstration of their efficacy was an alkaline electrolyzer developed with the B-CoP0.5@NC/NF electrodes, which achieved a cell potential of just 1.59 V at a current density of 10 mA cm-2.
"Our findings offer a blueprint for designing and synthesizing next-generation high-efficiency catalysts that can drastically reduce hydrogen production costs," stated Professor Lee with optimism. "This is an important step towards making large-scale green hydrogen production a reality, which will ultimately help in reducing global carbon emissions and mitigating climate change." This breakthrough from Hanyang University represents a significant stride towards a sustainable energy future, potentially unlocking the full potential of green hydrogen as a cornerstone of clean energy.
