| Ta3N5@Ta2O5的可控制备及可见光催化分解水析氢性能 | |
| Controllable Synthesis of Ta3N5@Ta2O5 and Properties of Splitting Water into Hydrogen under Visible Light Irradiation | |
| 摘要: 以水热法制备的Ta2O5纳米粒子为前驱体，利用高温氮化技术成功制备了核壳异质结构的Ta3N5@Ta2O5纳米光催化剂。采用XRD、XPS、TEM、N2吸附-脱附测试、DRS及电化学测试等分析手段，考察了氮化温度和氮化时间对样品的表面组成、晶粒尺寸、晶面结构、能带结构及载流子分离效率的影响规律。在NH3气流量50 mL·min-1的条件下，当氮化温度为750℃，控制氮化时间能够对纳米Ta2O5样品的带隙结构在3.86~2.08 eV间有效调控，相应地样品逐渐从Ta2O5经TaON@Ta2O5转化为Ta3N5@Ta2O5；当氮化时间为3 h，氮化温度由750℃升高到900℃，Ta3N5@Ta2O5样品的带隙窄化至2.04 eV；当氮化温度为850℃，氮化时间延长至12 h，Ta2O5完全氮化为Ta3N5，带隙进一步窄化至2.02 eV。经850℃氮化3 h样品，壳层Ta3N5界面转化为高活性（110）晶面，光生载流子分离效率最大，在可见光（λ>420 nm）照射下光解水析氢活性最高，达21.75 μmol·g-1·h-1。 | |
| 关键词: Ta2O5 Ta3N5 异质结 光催化 分解水 半导体 非均相催化 电荷转移 | |
| 基金项目: 黑龙江省教育厅科学技术研究项目（No.12531213）和光电带隙材料省部共建教育部重点实验室开放课题（No.PEBM201708）资助 | |
| Abstract: Ta3N5@Ta2O5 nano-photocatalysts with shell-core heterojunction structure were successfully synthesized by a high-temperature ammonolysis of Ta2O5 nano-powders prepared by a hydrothermal method. Effects of nitridation temperature and nitridation time on surface composition, crystal plane structure, energy band structure, and carrier separation efficiency of the samples were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2 adsorption-desorption test, UV-Vis diffused reflectance spectroscopy (DRS), and electrochemical measurements. Under the condition of ammonia flowing rate of 50 mL·min-1 and nitriding temperature of 750℃, the bandgap structure of Ta2O5 samples could be controlled effectively between 3.86~2.08 eV, through transforming the phases from Ta2O5 to TaON@Ta2O5, and to Ta3N5@Ta2O5. When the nitriding temperature was elevated from 750 to 900℃, the bandgap energy of Ta3N5@Ta2O5 was further narrowed to be about 2.04 eV by 3 h nitridation. When the nitridation time was prolonged to 12 h, Ta2O5 was completely transformed into Ta3N5, of which the bandgap energy was further narrowed to 2.02 eV, by nitriding at 850℃. After nitriding at 850℃ for 3 h, the crystal plane of Ta3N5 shell gradually changed to the (110), and the sample possessed the highest carrier separation efficiency, on which optical H2 evolution rate reaches 21.75 μmol·g-1·h-1 under visible light (λ>420 nm) irradiation. | |
| Keywords: Ta3N5 Ta2O5 heterojunction photocatalysis water splitting semiconductors heterogeneous catalysis charge transfer | |
| 投稿时间：2018-02-11 修订日期：2018-06-11 | |
| 摘要点击次数: 2207 | |
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| 张微,姜洪泉.Ta3N5@Ta2O5的可控制备及可见光催化分解水析氢性能[J].无机化学学报,2018,34(9):1591-1599. | |
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