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Co–Zn–N–C catalyst (MCZC) with neighboring Co and Zn pairs anchored on hollow carbon nitride was constructed by the direct etching of zeolitic imidazolate frameworks assembled with Co and Zn. Adequate characterizations and density functional theory (DFT) studies confirmed the successful construction of non-bonding Co and Zn pairs with enhanced electron transfer on Co sites by adjacent Zn sites. Based on the synergy of adjacent Co and Zn atom pairs, the MCZC/Perxymosulfate (PMS) system achieved 99.6% Tetracycline (TC) degradation in 24 min with a mineralization rate of 55.8% and PMS decomposition efficiency of 73.1%. DFT calculation based on the Fukui index identified the sites susceptible to attack by the active species. TC degradation pathways could be inferred, and reduced toxicity of intermediates was observed. This work provides new insights into the design of MOF-derived bimetallic catalysts and the importance of the interaction between adjacent metal active sites to catalytic performance. [Display omitted] • Co, Zn doped hollow carbon nitride catalyst was synthesized by etching Co 0.5 Zn 0.5 -ZIF. • Co sites were highly activated by adjacent Zn atoms via non-bonding interaction. • MCZC/PMS system achieved efficient tetracycline degradation and risk control. • The unique structure provides MCZC catalyst with high stability and low metal leaching. [ABSTRACT FROM AUTHOR]

The low specific surface area, poor porosity, and weak charge transport caused by the disordered morphology of metal-N-site catalysts are the main factors limiting their environmental applications. Therefore, a hollow-nanotube carbon nitride (Cu-HNCN) catalyst with CuN x sites dispersed in a hollow nanotube-like CN was constructed and used for the degradation of organic pollutants via the photo-Fenton (PF) process. The high specific surface area, rich porosity, and good visible-light trapping capability of the Cu-HNCN nanotubes were identified. The Cu-HNCN/PF system achieved 96.0% degradation efficiency of tetracycline within 50 min and showed efficient degradation of various antibiotic contaminants. Moreover, the short Cu-N bonds contributed to the improved stability and decreased copper leaching in the Cu-HNCN/PF system. Cu-HNCN, with its enhanced photogenerated charge generation, separation, and transport, was the key to the generation of abundant active species and efficient degradation of pollutants. In addition, frontier electron density theory successfully distinguished the roles of different types of active species in the degradation process. This work provides new insights into the development of catalysts with high stability and accelerated electron transfer to enhance the application of the PF process in practical wastewater purification. [Display omitted] • Hollow-nanotube carbon nitride catalyst were designed for antibiotics degradation. • CuN x sites are highly dispersed for effectively avoiding the loss of Cu ions. • Degradation process was contributed by the abundance of active species and nanotube properties. • It provides catalyst with high stability and accelerated electron transfer for photo-Fenton process. [ABSTRACT FROM AUTHOR]