Hierarchically macroporous Fe@ZIF-67-loaded carbonized rattan as a self-supporting electrode for efficient water electrolysis

The advancement of highly efficient bifunctional electrodes tailored for water electrolysis, specifically targeting the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), is pivotal for sustainable hydrogen production. However, sluggish reaction kinetics and elevated overpotentials pose formidable hurdles. In this study, an innovative strategy is introduced by integrating Fe@ZIF-67 onto self-supporting carbonized rattan stem (CR), leveraging its distinctive through-channel macroporous architecture to bolster catalytic efficacy. The self-supporting CR substrate not only enhances mass transport but also facilitates uniform deposition of ZIF-67, ensuring optimal exposure of active sites. A comparative analysis with carbonized basswood (CW) underscores the superior performance of the macroporous CR substrate in augmenting both OER and HER activities. Notably, the Fe@ZIF-CR self-supported electrode achieves an overpotential of 208 mV at 10 mA cm⁻² for oxygen evolution and 317 mV at 100 mA cm⁻² for hydrogen evolution. Additionally, the self-supporting nature of the CR substrate guarantees long-term stability and mitigates catalyst loss during operation. These findings underscore the synergistic advantages of the macroporous structure and ZIF-67 active sites, offering fresh perspectives on the utilization of biomass-derived carbon materials in sustainable energy technologies.