NaNbO_(3)粉末的形貌调控及其压电催化性能

Morphology control of NaNbO_(3) powder and its piezoelectric catalytic properties

采用固相法合成NaNbO_(3)微米粉、水热法合成NaNbO_(3)纳米线、熔盐法合成NaNbO_(3)微米片,探究合成温度对物相和形貌的影响规律,获得最佳反应温度。对比三种不同形貌的NaNbO_(3)压电催化效率,探究影响催化效率的因素。结果表明:在相同的催化条件下,NaNbO_(3)微米粉、NaNbO_(3)纳米线和NaNbO_(3)微米片在30 min内分别降解了92.4%、57.9%和92.3%的罗丹明B(Rh B)染料,相应的反应速率常数k分别为0.08893 min^(-1)、0.02723 min^(-1)和0.08013 min^(-1)。不同于文献中纳米线和纳米片因更易变形而具有较好的催化性能,本文中NaNbO_(3)微米粉表现出了最佳的压电催化性能。高温处理后NaNbO_(3)微米粉和NaNbO_(3)微米片获得更高的结晶度,催化效果更好。其中,NaNbO_(3)微米粉具有更大的比表面积,约是微米片的3倍,反应速率常数k只有微米片的1.1倍,这是由于NaNbO_(3)微米片的片状结构易变形具有更高的压电势。而易变形的纳米线因结晶度低催化效果最差。综合以上影响因素,影响催化效果的因素主要有结晶度、比表面积、形貌等。

The solid-phase method was used to synthesize NaNbO_(3)micropowders,the hydrothermal method was used to synthesize NaNbO_(3)nanowires,and the molten salt method was used to synthesize NaNbO_(3)microsheets.The piezoelectric catalytic efficiency of NaNbO_(3)with three different morphologies was compared,and the factors affecting the catalytic efficiency were explored.Under the same catalytic conditions,NaNbO_(3)micropowders,NaNbO_(3)nanowires and NaNbO_(3)microsheets degrade 92.4%,57.9%and 92.3%of RhB within 30 min,respectively,and the corresponding reaction rate constants k are 0.08893 min^(-1),0.02723 min^(-1)and 0.08013 min^(-1),respectively.Unlike the nanowires and nanosheets in the literature,which have better catalytic performance due to their easier deformation,the NaNbO_(3)micropowders in this paper exhibit the best piezoelectric catalytic performance.After research,it is found that NaNbO_(3)micronpowders and NaNbO_(3)microsheets obtained higher crystallinity after high temperature treatment,and the catalytic effect was better.Among them,the NaNbO_(3)micronpowder has a larger specific surface area,which is about 3 times of that of the micronsheets,and the reaction rate constant k is only 1.1 times that of the micronsheets.The easily deformable nanowires have the worst catalytic effect due to their low crystallinity.Based on the above factors,the main factors affecting the catalytic effect are crystallinity,specific surface area,and morphology.Which factors play a leading role must be fully analyzed.