Study On The Preparation Of Ti₄O₇ By Microwave Rapid Heating Reduction Of TiO₂

Magn�li phase titanium suboxide are a series of materials with excellent electrochemical performance.They have high conductivity,good acid and alkali corrosion resistance,wide electrochemical window.Titanium suboxide have broad application prospects in the field of electrochemistry.Ti₄O₇has the best performance among a series of titanium suboxide.But the preparation of single-phase Ti₄O₇is difficult.The preparation time is long and the cost is high,which restricts the large-scale production and application of Ti₄O₇.At present,it is urgent to explore a suitable Ti₄O₇preparation process to improve the application of Ti₄O₇materials.Thermodynamic calculations was carried out to determine the possible experimental conditions for preparing Ti₄O₇and provide theoretical guidance for the experiment.Based on the calculation result the reducing agent was determined.Experiments on preparation of Ti₄O₇by microwave heating reduction of TiO₂were performed.According to the experimental results,determine whether it is suitable as a reducing agent for preparation of Ti₄O₇,and explore the influence of different process parameters on product phase.The main findings are as follows:The thermodynamic calculation of urea reduction of TiO₂shows that at a temperature of about 1000?,NH₃pyrolyzed by urea can reduce TiO₂to titanium suboxide.However,because NH₃escapes in a flowing argon atmosphere,NH₃is quickly diluted.The reducing ability is greatly weakened.Therefore,the short-term reduction of TiO₂only during the escape of the sample is not enough to reduce all TiO₂to titanium suboxide.The reduction effect is not ideal.Magnesium reduction TiO₂is a kind of magnesium thermal reduction.Thermodynamic calculations show that magnesium reduction of TiO₂to prepare Ti₄O₇can be carried out at low temperatures.However,the experimental results show that although titanium suboxides were produced,they only existed in small amounts when the magnesium content is low.When the magnesium content is higher,it is excessively reduced to TiO.At the same time,under the effect of microwave,Mg O and TiO₂further react to produce Mg O-TiO₂materials such as magnesium titanate.Titanium suboxides were difficult to separate from the product.Glucose will be converted into activated carbon under the condition of microwave heating.Thermodynamic calculations show that the reduction of TiO₂by C to prepare TiO₂will take place at a temperature of about 1000?.The experimental results show that glucose reduction TiO₂successfully prepared Ti₄O₇with higher purity to 99%.Ti₄O₇was prepared under the conditions of m(C₆H₁₂O₆)/m?TiO₂?=3:10,reduction temperature1000?,reduction time 4 h.The grain size is between 0.2?5?m,and there is no phenomenon of excessive sintering growth compared with TiO₂.Although the selected three reducing agents all have titanium suboxides.But urea as the reducing agent TiO₂has a lower degree of reduction.Magnesium as a reducing agent has a small amount of titanium oxide and is easily reduced too much.The generation of magnesium titanate and other substances makes it difficult to separate titanium oxide.Therefore,only glucose is suitable as a reducing agent for the preparation of Ti₄O₇.