Hydrothermal Synthesis And Photocatalytic Properties Of ZnO Nano Materials

With the rapid development of modern industry,water pollution and energy shortages have become two important factors which seriously threaten human health and prevent the development of society.Semiconductor photocatalyst as a promising strategy has attracted worldwide attention and research interest.Therefore,various semiconductor materials have been rapidly developed as active semiconductor photocatalysts.ZnO is an attractive photocatalytic material owing to its superior and diverse properties,such as non-toxicity,low cost,easy to synthesis and high photocatalytic activity,which has been widely researched in photocatalysis field.In this article,ZnO materials have been successfully prepared on Al,Cu and Zn substrates by hydrothermal method at low temperature.The photocatalytic properties and possible photocatalytic mechanism were investigated.The mainly research contents are as follows:Firstly,large scale and high density ZnO nanoplates have been successfully fabricated on Al substrate via a simple hydrothermal method at room temperature.The as-prepared ZnO nanoplates were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）and photoluminescence（PL）.A possible growth mechanism was also proposed.The photocatalysis test shows that ZnO nanoplates exhibit high efficient photocatalytic degradation of organic molecules.Moreover,the photocatalytic circulation experiments demonstrate high stability of ZnO nanoplates.Secondly,large-area ZnO/Cu₂ O heterojunction have been successfully synthesized on Cu foil through a simple two-step solution method at near room temperature.The current–voltage measurement of ZnO/Cu₂ O heterostructure shows a typical rectifying characteristic.Moreover,the photocatalytic test indicates that ZnO/Cu₂ O heterojunction exhibits higher efficient photocatalytic degradation of congo red dyes compared with Cu₂ O octahedral and ZnO nanorods.The possible photocatalytic mechanism of ZnO/Cu₂ O heterojunction is also presented.The high photocatalytic activity of ZnO/Cu₂ O heterojunction could be mainly attributed to the expansion of spectral response range and the separation of photogenerated electron–hole pairs.Thirdly,ZnO nanocones（ZnO NCs）structure have been fabricated on Zn foil through the reaction of metal Zn and water at low temperature.The characterization of ZnO NCs photocatalysis shows high photocatalytic activity to methyl orange（MO）and methylene blue（MB）.This simple and low cost method of ZnO preparation on Zn foil has great prospect in the field of energy saving and water treatment.