(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 采用固相法合成NaNbO3微米粉、水熱法合成NaNbO3納米線、熔鹽法合成NaNbO3微米片，探究合成溫度對(duì)物相和形貌的影響規(guī)律，獲得最佳反應(yīng)溫度。對(duì)比三種不同形貌的NaNbO3壓電催化效率，探究影響催化效率的因素。結(jié)果表明：在相同的催化條件下，NaNbO3微米粉、NaNbO3納米線和NaNbO3微米片在30 min內(nèi)分別降解了92.4%、57.9%和92.3%的羅丹明B(RhB)染料，相應(yīng)的反應(yīng)速率常數(shù)k分別為0.08893 min-1、0.02723 min-1和0.08013 min-1。不同于文獻(xiàn)中納米線和納米片因更易變形而具有較好的催化性能，本文中NaNbO3微米粉表現(xiàn)出了最佳的壓電催化性能。高溫處理后NaNbO3微米粉和NaNbO3微米片獲得更高的結(jié)晶度，催化效果更好。其中，NaNbO3微米粉具有更大的比表面積，約是微米片的3倍，反應(yīng)速率常數(shù)k只有微米片的1.1倍，這是由于NaNbO3微米片的片狀結(jié)構(gòu)易變形具有更高的壓電勢(shì)。而易變形的納米線因結(jié)晶度低催化效果最差。綜合以上影響因素，影響催化效果的因素主要有結(jié)晶度、比表面積、形貌等。
關(guān)鍵字: NaNbO3；形貌調(diào)控；壓電催化；結(jié)晶度；壓電勢(shì)；比表面積
（State Key Lab of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The solid-phase method was used to synthesize NaNbO3 micropowders, the hydrothermal method was used to synthesize NaNbO3 nanowires, and the molten salt method was used to synthesize NaNbO3 microsheets. The piezoelectric catalytic efficiency of NaNbO3 with three different morphologies was compared, and the factors affecting the catalytic efficiency were explored. Under the same catalytic conditions, NaNbO3 micropowders, NaNbO3 nanowires and NaNbO3 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 NaNbO3 micropowders in this paper exhibit the best piezoelectric catalytic performance. After research, it is found that NaNbO3 micronpowders and NaNbO3 microsheets obtained higher crystallinity after high temperature treatment, and the catalytic effect was better. Among them, the NaNbO3 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.
Key words: NaNbO3; morphology control; piezoelectric catalysis; crystallinity; piezoelectric potential; specific surface area
