二氧化钒相变材料制备的影响因素研究OA

The vanadium dioxide(VO2).phase-change materials exhibit promising application prospects owing to their unique temperature-controlled metal-semiconductor phase transition behavior.In this work,VO2 phase-change materials were prepared via the hydrothermal method with ammonium metavanadate(NH4VO3)as the precursor and water as the solvent,and different reducing agents were adopted to fabricate the samples.The target product VO2(M)(M represents the monoclinic phase P21/c)was successfully synthesized via the reaction between oxalic acid(H2C2O4)and NH4VO3.It is found that by adjusting the molar concentration of the precursor and the solution pH,a lower pH not only increases the product yield but also results in a larger particle size of the samples.Moreover,the sample surface gradually becomes rough with decreasing pH,accompanied by the formation of other vanadium oxides during the generation of VO2.The results demonstrate that the product is dominated by VO2(M)when the solution pH is higher than 0.8,whereas miscellaneous phases including V6O13,V3O7,V4O7 and V2O5 are formed at pH below 0.8.