Controlled solvothermal synthesis of ZnO nanoparticles using non-destructive Mg-based channel templates for enhanced photocatalytic performance

ZnO nanoparticles (NPs) were synthesized by solvothermal method using novel water soluble magnesium-based coordination polymers (MCPs) with rutile and anatase topologies as non-destructive templates. The strong interaction between ZnO–Mg(INT)2·H2O or ZnO-(Mg(NT)2 interface results in the increase of nucleation points and the decrease of grain sizes, and well-ordered growth of ZnO NPs via channel template effect. Comparing with other samples, S4 synthesized by the Mg(NT)2 template with anatase-type topology possesses the highest charge separation efficiency, largest surface area and pore volume, and exhibits the best photodegradation efficiency and k, which are 87.5%, 0.01752 min−1 (Rhodamine B, RhB) and 61.6%, 0.00776 min−1 (Tetracycline, TC) for 120 min, respectively. The photocatalytic efficiency for RhB over S4 changes slightly after five runs, which exhibits excellent photostability under ultraviolet–visible (UV–Vis) light irradiation. ·O2− and ·OH radical species play the important role in the photocatalytic process. Notably, the addition of MCP templates significantly improves active ·OH of ZnO via interface interaction, which is also favourable for the enhancement of photocatalytic performance of ZnO NPs. Additionally, photodegradation mechanism and pathways, and formation over ZnO were proposed. The work provides a new idea for designing non-destructive and easily-removed channel templates for the synthesis of ZnO NPs.