Controllable synthesis of zinc oxide with ionic liquid and supramolecular gel as co-template for the degradation of organic dyes

Zinc oxide was synthesized with ionic liquid tetramethylammonium glycine ([N1111][Gly]) and supramolecular gel N-lauro-L-glutamic acid-di-n-butylamide (GP-1) as co-template by solvothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectrometer. The effects of templating agent dosage and aging time on the morphology, mesoporous structure, and crystal phase of ZnO were investigated. The results demonstrate that the ionic liquid [N1111][Gly] and GP-1 organogel synergistically control the growth orientation of the crystal, and the morphology of ZnO varies with the templating agent dosage and aging time. The as-synthesized samples were applied in the catalytic degradation of Congo red under simulated solar light irradiation. In particular, the synthesized sample (MZ-3-8) with nanosheets morphology exhibited the best catalytic performance with a degradation rate up to 98% for 90 min, clearly superior to commercial ZnO and P-25. Furthermore, the catalyst can be cycled at least eight times with little loss of photocatalytic activity.