Synthesis Of Sea Urchin-like Cuprous Oxide With Hollow Glass Microspheres As Cores And Its Preliminary Application As A Photocatalyst

Core-shell structure material is a new type of composite material, just rising inrecent years. It has potential application prospect in many fields due to its uniquestructure and properties, and researchers have showed greatly interest in it. Over thepast several years, the creative achievements of the core-shell structure compositeshave proved the development prospect is ascendant in the cutting edge.Cuprous oxide (Cu2O) microcrystals with sea urchin-like morphologies weresuccessfully prepared on the surface of hollow glass microspheres (HGMs) usingsodium sulfite (Na2SO3) as the reducing agent and sodium acetate-acetic acid(NaAc-HAc) as buffer solution in copper sulfate (CuSO4) solution. The products werecharacterized by X-ray diffraction (XRD), scanning electron microscopy (SEM),transmission electron microscope (TEM) and differential thermal-thermogravimetry(DTA-TG). Through the effect factors of cuprous oxide plating progress wereinvestigated, the results show that adding buffer solution into Na2SO3solution, theloading capacity of hollow glass microspheres for0.4g/L, the concentration of coppersulfate solution for0.05mol/L, using the intermittent mixing, and the reaction timefor180min, the reaction temperature for85℃and the addition amount ofdodecylbenzenesulfonic acid sodium for7%of total quality can prepare a perfectplating effect and the shape of the sea urchin cuprous oxide is neat. Based on the SEMimages of the as-obtained samples, it was found that the HGMs acted as a crucial rolein the formation of sea urchin-like Cu2O. The as-prepared sea urchin-likemicrocrystals are purer cubic phase Cu2O and polycrystalline unit. Cuprous oxidecrystals grow along the (110) direction and appear many dislocation in the growthprocess. The as-prepared products can be oxidized at240℃.The photocatalytic of methyl orange with the as-prepared sea urchin-like Cu2O under the visible light was investigated. Methyl orange as a textile dye with thecharacteristics of complex composition, high color and emissions, high toxicity andpoor biodegradability, could be used to detect catalytic ability of as-prepared Cu2O. Aseries of experiments were conducted to investigate the operational parameters undervisible light irradiation such as initial dye concentration, catalyst dosage, reactiontemperature, different anion, pH value and reuse of catalyst. The results show that theoptimal parameters as follows: the illumination time is30min, the amount of catalystis0.5g/L, and the pH value is10.0. The photodegradation efficiency of methylorange can reach94.25%in30min.The sea urchin-like Cu2O have dramaticallyimproved photo-catalytic activity comparing with pure Cu2O particles. At lowerTtemperature, the catalytic ability of cuprous oxide increase with the increasingtemperature; at higher temperature, catalytic ability has a decreasing trend. Afterseven times recycling use, the sea urchin-like Cu2O prepared still shows the highphoto-catalytic efficiency and stability. In addition, it was found that the kinetics ofthe dyes degradation follow the Langmuir-Hinshelwoo model and a first orderreaction. The activation energy and preexponential factor of sea urchin-like Cu2O are41.18KJ/mol and1.06×106, respectively.