Cobalt boride derived from metal-organic framework as highly efficient catalyst for tetracycline degradation with peroxymonosulfate activation

The development of highly efficient and easily recyclable metal borides intended for the activating on of peroxymonosulfate (PMS) to eliminate organic pollutants presents a significant challenge. The resulting CoxB/NC450, which was synthesized through boronation followed by calcination, exhibited significant efficacy in degrading tetracycline (TC), achieving a degradation efficiency of 96 % and a rate constant of 0.210 min-1 over a 30 min period. This system demonstrates excellent degradation capabilities across a wide pH range, good tolerance to inorganic anions and humic acid, and stable recovery after five cycles. The removal rate of TC from actual water bodies exceeds 85 %, indicating that CoxB/NC-450 exhibits resistance to interference from real water environments. The addition of transition metals combined with boron may modify the local electronic structure of the metal due to the distinct semimetallic characteristics of boron, which allows its vacant orbitals to easily accept electrons, thereby influencing the related catalytic processes. Furthermore, the subsequent carbonization, which results in a nitrogen-doped carbon structure, generally improves the conductivity and longevity of the catalyst. This study lays an essential groundwork for the advancement of metal borides from ZIF67 aimed at activating PMS for environmental pollutant remediation.