Research On The Preparation And Photocatalytic Activity Of NaInO₂Nanoparticles

In order to solve the problem of energy shortage and environmental pollution,studies of semiconductor photocatalytic technology has attracted much attention. Thistechnology has become the international research hotspot and one of the frontierdomains.The ABO2partial indate is a kind of inorganic semiconductor material.Sodium indate(NaInO2) has good photocatalytic activity, optical properties andphotoelectric conversion performance. However, There are only few reports onNaInO2. This paper based on the domestic and foreign research status of NaInO2photocatalyst, and focused on exploring the preparation method and the technologicalprocess. At the same time, the photocatalytic activity on the degradation of organicpollutants in the liquid phase environment was evaluated. The main conclusions weredrawn as following:(1) The stable rhombohedral system NaInO2materials were got under the solidstate reaction conditions: Na2CO3/In2O3=2,750℃heated2h. The average grain sizeof the products by calculation was about40nm, the morphology was cuboid particles.There were steps and end sawtooth on the surface of the small particles. Resultsshowed that the crystal growth of NaInO2conformed to the process of solid statereaction: diffusion-nucleation-growing up and followed the layer growth mechanism.(2) NaInO2materials were prepared by sol-gel method. The pure phase NaInO2was got at750℃heating3h after adding sufactants P123or F127with distilled wateras the solvent. When not adding surfactants, the products with a small amount ofimpurity phase were got at750℃heating2h, and the products of pure phase NaInO2were got at850℃heating2h.(3) Experiment of recycling catalysts showed that In(OH)3could be partiallyhydrolyzed by NaInO2in liquid phase environment. The contrast experiment foundthat the activity of In(OH)3on the methylene blue photo-catalytic degradation was notgood. NaInO2played the catalytic role.(4) The degradation rate on MB by NaInO2was91.8﹪under the irradiation ofultraviolet light for90min, and the rate was88.4﹪after irradiation120min underXenon lamp. The degradation rate of formaldehyde under ultraviolet light irradiationfor6h was48﹪which was higher than that of P25(25﹪). It relevant to the layercrystal structure of NaInO2, and the greater surface of nanometer material which canpromote the separation of electronic-hole and have strong adsorption ability.