Metal peroxide (MO2, with M=Ca, Sr, Ba) presents a compelling alternative to hydrogen peroxide (H2O2). With outstanding oxidative properties, remarkable chemical stability, high purity, and easy storage, it’s an ideal solution for a range of applications, including wastewater treatment and disinfection.
Recently, a pioneering research group at the Chinese Academy of Sciences has unveiled a groundbreaking self-cleaning electrode featuring a sophisticated micro-/nanostructure. This innovative design incorporates a highly active catalyst with targeted surface modifications, allowing for the remarkably stable synthesis of alkaline-earth MO2.
Their research highlights a significant breakthrough. The traditional synthesis process of MO2, which relies on the rapid decomposition of H2O2, often leads to suboptimal utilization of this powerful oxidizer.
In an impactful study led by Prof. LU Zhiyi at the Ningbo Institute of Materials Technology and Engineering (NIMTE) in collaboration with Prof. JIA Jinping at Shanghai Jiaotong University, researchers have introduced a groundbreaking in situ electrochemical synthesis process. This innovative solution aims to significantly reduce economic losses and enhance safety by addressing the inherent risks associated with the transportation and storage of hydrogen peroxide (H2O2).
The team demonstrated that high-concentration H2O2 can be efficiently produced via a two-electron electrochemical oxygen reduction (2e- ORR) reaction, converting it into manganese dioxide (MO2) on the electrode surface. However, a major obstacle is the strong adhesion of solid MO2, which can lead to system failures.
To overcome this challenge, the researchers designed a Ni-doped oxygenated carbon electrode with a Teflon coating (T-NiOC) featuring advanced micro-/nanostructures and low surface energy. This cutting-edge design dramatically minimizes the solid-liquid contact area, promoting the rapid detachment of the in situ-generated MO2 from the self-cleaning electrode surface. Such advancements promise to revolutionize H2O2 management, making processes safer and more efficient.
The T-NiOC electrode has achieved an outstanding accumulated selectivity of around 99% while exhibiting remarkable stability for over 1,000 hours at a current density of 50 mA cm-2 for the electrochemical synthesis of MO2, showcasing its broad application potential in various fields.
When compared to H2O2, the as-synthesized CaO2 outperformed it significantly in the degradation of tetracycline through hydrodynamic cavitation (HC).
This groundbreaking work has the potential to lead and revolutionize electrochemical solid-state synthesis reactions across multiple applications.
Journal reference:
- Minli Wang, Jinhuan Cheng, Wenwen Xu, Dandan Zhu, Wuyong Zhang, Yingjie Wen, Wanbing Guan, Jinping Jia & Zhiyi Lu. Self-cleaning electrode for stable synthesis of alkaline-earth metal peroxides. Nature Nanotechnology, 2024; DOI: 10.1038/s41565-024-01815-x
