Synergistic FeCu dual-metal sites on boron nitride for boosted redox cycling in Fenton-like reactions

Efficient and sustainable Fenton-like systems are highly desired for degrading persistent pollutants. However, their development is often hindered by the slow redox kinetics and poor durability of single active sites in conventional metal-based catalysts. Herein, we developed a bimetallic Fe/Cu catalyst (FeCu-BN) with highly dispersed metal sites anchored on boron nitride (BN), which offered boosted activity and stability via the cooperative redox cycles between Fe and Cu sites. The FeCu-BN catalyst achieved nearly 100% removal of sulfamethoxazole (SMX) within 20 min through activating peroxymonosulfate (PMS), with a rate constant of 0.421 min − 1 significantly surpassing those of its monometallic counterparts and other advanced catalysts. Systematic experiments and theoretical calculations revealed that the Cu sites not only optimized the electronic structure of the Fe sites but also provided electrons extracted from pollutants to promote the Fe 2+ /Fe 3+ cycle, thereby triggering concerted radical and non-radical reactions for SMX elimination. Consequently, the FeCu-BN/PMS catalytic system operated stably over a wide pH range and exhibited exceptional tolerance to various inorganic ions and complex aqueous matrices. Furthermore, in a continuous flow membrane reactor, the system maintained efficient SMX removal over 20 h without significant performance loss. This work uncovered the synergistic redox cycling mechanism in bimetallic catalysts and offered valuable insights for designing dual-site catalysts for environmental remediation.