Hydrophobicity strategy drives contact-electro-catalysis on natural silicate minerals.

Contact-electro-catalysis (CEC) at catalyst-water interfaces shows promise for wastewater purification, metal recovery, and H2O2 production, but catalyst design has mainly emphasized electron-withdrawing ability while overlooking interfacial water transfer. Here, we develop a hydrophobicity engineering strategy for natural silicate minerals to optimize catalyst-water contact by balancing the water approach and removal. As a representative non-fluorinated system, alkyl-modified minerals with moderate hydrophobicity (water contact angle of 125-148°) achieve a H2O2 yield of 350.0 μmol·L-1·h-1 under ultrasonication, outperforming fluorinated minerals. Mechanistic analysis indicates that this enhancement arises from improved interfacial contact efficiency rather than stronger electron-withdrawing ability alone. This strategy also remains effective under weak-force conditions, enabling self-powered CEC in a natural river. The modified minerals selectively enriched microorganisms associated with oxidative stress resistance and oxidized organic carbon utilization, including Novosphingobium sp. Together, these findings identify hydrophobicity regulation as an effective contact-optimization strategy for CEC.