Construction of CoOOH/g-C3N4 Z-scheme heterojunction for peroxymonosulfate-mediated sulfamerazine degradation

CoOOH/g-C3N4 Z-scheme heterojunction is synthesized for PMS activation. • Sustained Co2+/Co3+ redox cycle promotes stable PMS activation. • The synergistic catalytic system exhibits excellent pollutant removal capacity. To address the challenges of high carrier recombination rate and insufficient active sites in the photocatalytic activation of peroxymonosulfate (PMS) system, this study reports the in situ synthesis of a CoOOH/g-C 3 N 4 Z-scheme heterojunction via an interface regulation strategy, identified the synergistic “Z-scheme charge transfer-PMS activation” mechanism, and realized efficient degradation of sulfamerazine (SMR). Experimental characterization and theoretical calculation confirmed that the CoOOH and g-C 3 N 4 not only induce a Z-scheme charge transfer pathway to preserve strong redox capacity, but also elevate the oxygen vacancies concentration in CoOOH. Z-scheme heterojunction significantly enhances the visible light response capability and improves the separation and migration efficiency of photogenerated electron-hole pairs. Among the synthesized photocatalysts, CoOOH/CN-10 demonstrated the optimal catalytic performance. Radical trapping experiments revealed that the degradation process was primarily driven by electrons (e ⁻ ) and singlet oxygen ( 1 O 2 ), while superoxide radicals (•O 2 ⁻ ) and hydroxyl radicals (•OH) played a secondary role. This work not only presents an efficient catalyst for PMS activation but also provides valuable insights into the design of Z-scheme photocatalyst for aquatic pollutant remediation. Download: Download high-res image (227KB) Download: Download full-size image