Hollow octahedral Cu doped Zn3In2S6 with spatially engineered high-exposure adsorption-catalysis co-sites via self-template heteroatom doping for accelerated water remediation

Neonicotinoid pesticides pose a significant threat to non-target organisms and human health. To overcome the efficiency bottleneck caused by misaligned adsorption and catalytic sites in Zn 3 In 2 S 6 -based photocatalysis, a hollow octahedral Cu-doped Zn 3 In 2 S 6 (CuZIS) is engineered using Cu-MOF as a self-template. This design achieves spatially unified and fully exposed adsorption–catalytic co-sites. The introduced Cu centers efficiently induce pronounced electron delocalization to suppress carrier recombination while coordinating the pyridinic nitrogen of imidacloprid (IMD) to enhance IMD enrichment. The hollow architecture enlarges the specific surface area from 14.66 to 131.65 m 2  g −1 and affords a saturation adsorption capacity of 46.04 mg g −1 . Under simulated visible light, 99.4% IMD is removed within 30 min—4.8 times faster than pristine Zn 3 In 2 S 6 . The CuZIS demonstrates exceptional robustness in complex water matrices containing ions, organic matters, and microplastics. It also exhibits superior broad-spectrum activity against various organic contaminants, affirming its potential for water treatment. Cu centers convert O 2 into 1 O 2 and • O 2 − ${\mathrm{O}}_2^{-}$ , triggering hydroxylation, denitration, and ring-opening at the C9, C10, N11, and N15 sites of IMD to yield low-toxicity products. This work validates self-template heteroatom doping for constructing high-performance photocatalysts with integrated adsorption-catalysis co-sites for advanced water treatment.