Cetyltrimethylammonium bromide-regulated in situ synthesis of graphitic carbon nitride on zeolitic imidazolate framework-8 for wavelength-adaptive heterojunctions in photocatalytic degradation of tetracycline hydrochloride

In this study, we employed an interfacial engineering strategy to construct a hierarchical heterojunction, ZIF-8/g-C₃N₄/CTAB (denoted as ZGC), in situ on a g-C₃N₄ substrate. The g-C 3 N 4 , synthesized via the urea pyrolysis method, served as a structural template, with its unique electronic structure and surface properties facilitating the separation and migration of photogenerated charge carriers. Upon dispersion in methanol, it functioned as a coordination reaction medium, directing the oriented nucleation of the ZIF-8 crystalline phase on its surface through hexahydrate zinc nitrate and 2-methylimidazole, facilitated by CTAB, culminating in a distinctive “core-shell” structure that enhances photocatalytic activity. This heterojunction demonstrated remarkable spectral adaptability: within a 30 ppm tetracycline hydrochloride degradation system (0.5 g/L catalyst), the degradation rates achieved under ultraviolet, blue laser, and visible light were 97.79 %, 95.38 %, and 94.48 %, respectively, within a 120-min period. The purpose of this comparison is to investigate the impact of different light sources on photocatalytic activity, thereby providing a theoretical basis for the selection of light sources in practical applications. We have made a novel discovery concerning wavelength-controlled reaction pathways, which offers a pioneering paradigm for interfacial engineering in the development of spectrally adaptive catalysts for environmental remediation.