Entropy as a Design Principle for Boosting Water Splitting: A Case Study on 1,3,5‐Benzenetricarboxylic Acid‐Based Metal–Organic‐Frameworks

Abstract Metal–organic‐frameworks (MOFs) are promising platforms for electrocatalytic water splitting due to their structural tunability, but conventional MOFs often suffer from poor electrical‐conductivity and resultant sluggish electrocatalysis. To address this, we investigate entropy modulation as a design strategy for enhancing catalytic activity. We hypothesize that incorporating multiple metal species into a single MOF structure will induce synergistic effects that improve overall catalytic performances. Using 1,3,5‐benzenetricarboxylic acid (BTC) as the organic‐linker, we synthesized a series of MOFs with increasing compositional complexity, from monometallic Ni‐MOF (M‐I) to high‐entropy MnFeCoNiCu‐MOF (M‐V). Electrochemical testing in 1 M KOH showed that M‐V delivers low hydrogen and oxygen evolution reaction (HER and OER) overpotentials of 317 and 280 mV at 10 mA cm −2 , with Tafel slopes of 58 and 40 mV dec −1 , respectively. Moreover, in overall water splitting (OWS) cell, M‐V delivered a stable catalytic current, declining modestly from 10.2 to 9.7 mA cm −2 at 1.92 V after 72 h of continuous operation. These enhancements arise from entropy‐driven synergism that improves both electron transport and active surface area, surpassing the activity of conventional benzenecarboxylic acid‐based MOFs. Our findings demonstrate that high‐entropy engineering is a powerful and scalable approach to designing next‐generation water splitting electrocatalysts.