Research On The Synthesis And Characterization Of Mesoporous Tungsten Oxide Materials

In this article,mesoporous tungsten trioxide materials are synthesized by sol-gel method,employing nonionic surfactant block copolymer as a template,using tungsten hexachloride as an inorganic precursor and ethanol as solvent.And several methods such as X-ray diffraction(XRD)and nitrogen adsorption-desorption isotherms were employed to characterize the mesoporous tungsten trioxide.Employing nonionic surfactant block copolymer(P123 or F127)as template,the effects of raw materials ratio,aging temperature,aging time,calcination temperature and calcination time have been investigated in details.Employing P123(or F127)-low molecular resol as a soft-soft double template and P123-mesoporous polymer resin as a soft-hard double template,the effects of double templates have been investigated.The experimental results are shown that the synthetic method can prepare ordered mesoporous tungsten oxide material with monoclinic type of the hole wall.Employing P123 as a template,the calcination process with low calcination temperature and long calcination time of constant temperature,can avoid mesoporous being collapsed.It improves the crystallinity and specific surface area of mesoporous materials effectively.Employing F1 27 as a template,it can achieve the rapid synthesis of mesoporous WO3 material and reduce the aging time of the material greatly.In the calcination process,phenolic resin can form a rigid framework structure using cross-linked polycondensation.It can support the channels and prevent the collapse of the channels.Employing P123(or F127)-low molecular resol as a soft-soft double template and P123-mesoporous polymer resin as a soft-hard double template can improve specific surface area and pore volume of the mesoporous WO3 significantly.It makes up for deficiencies of the single soft template.Aging and calcination process are key factors to form the mesoporous materials.In addition,employing P123 as a template,mesoporous polymer resin have more uniform particle size distribution and more orderly arrangement by hydrothermal synthesis.Employing P123-mesoporous polymer resin as a soft-hard double template,extending the calcination time is conducive to the improvement of specific surface area and pore volume of mesoporous material.This is the same with the P123 as a single template to synthesize mesoporous WO3 material.