Abstract: Pseudo-ternary phase diagrams of microemulsion system of hexadecyltrimethylammonium bromide (CTAB)/n-butanol/cyclohexane/zinc nitrate or ammonium oxalate solution were drawn by turbidimetry,and the best mass ratio of CTAB to n-butanol was 1∶1 in the maximum stable region of microemulsion.Under this condition,when m(CTAB+n-butanol)∶m(cyclohexane) was 3∶7,zinc oxalate dihydrate,which was the precursor of ZnO,was prepared by a microemulsion method using zinc nitrate and ammonium oxalate as raw materials.ZnO materials were prepared by calcining zinc oxalate dihydrate.The effects of R (the molar ratio of water to CTAB) and reactant concentration on the structure,morphology,optical property and photocatalytic property of ZnO materials were studied.Results show that the morphologies of ZnO power are rodlike and they exhibit hexagonal wurtzite structure.The sizes of samples are affected by R and reactant concentration.All the samples have good photocatalytic effect on the catalytic degradation of methylene blue solution under the irradiation of 300 W Hg lamp,and the photocatalytic degradation process follows quasi-first-order kinetics.Among which the degradation rate of methylene blue solution achieves 97.0% for 90 min illumination and the corresponding reaction rate constant k is the largest,and with best photocatalytic property,when the reactant concentration is 0.15 mol/L,R=15.

Key words: hexadecyltrimethylammonium bromide, zinc oxide, microemulsion, photocatalysis