All-Scale Structural Optimization of Resiliently Crystalline Na-Ce-Sn-S Chalcogel for Efficient Oxygen Evolution...

Area of Science:

• Materials Science
• Inorganic Chemistry
• Electrochemistry

Background:

• Metal cations are crucial in chalcogel structure and properties, but their local transformations and ordering are understudied.
• Existing research often focuses on atomic-scale metal linker functionality, neglecting broader structural evolution.

Purpose of the Study:

• To investigate the unprecedented role of cerium ions in directing the formation of a sustainable 2D crystalline chalcogel.
• To explore the structural transformation and long-range ordering influenced by cerium.
• To evaluate the electrocatalytic performance of the resulting cerium-tin-sulfide (CTS) material.

Main Methods:

• Synthesis of cerium-tin-sulfide (CTS) chalcogels with varying cerium content.
• Characterization of the crystalline framework, including coordination transformation of tin species.
• Evaluation of electrocatalytic activity for the oxygen evolution reaction (OER).

Main Results:

• Demonstrated the formation of a 2D crystalline CTS chalcogel directed by cerium ions.
• Observed coordination transformation of SnS4 tetrahedra into distorted Sn3S4 broken-cube clusters, forming a [Sn3S7]n2n- layered geometry.
• Optimized CTS-5 chalcogel showed superior OER performance: 300 mV overpotential, 80 mV dec-1 Tafel slope, and 50-hour stability at 10 mA cm-2.

Conclusions:

• Cerium ions play a critical role in templating and stabilizing the 2D crystalline structure of CTS chalcogels.
• The enriched Ce3+ state enhances electrocatalytic activity.
• This work introduces a new class of aerogel materials with robust 2D crystallinity and tunable functionality.