窄带隙铁酸铋的优化制备及其压电光催化性能

Optimized construction of BiFeO_(3)with narrow bandgap and its piezo-photocatalytic activity

针对光催化反应过程中光生电子与空穴复合率高、可见光谱吸收利用率低等问题,利用水热法合成具有较窄带隙的钙钛矿型铁酸铋(BiFeO_(3))。研究结果表明:在超声与光照的协同作用下,反应原料中NaOH浓度为8 mol/L时合成的BiFeO_(3)样品的性能最佳,在15 min内对靛蓝胭脂红染料的降解率达97.6%,拟合得到的一级反应速率常数为0.2036 min^(−1),其原因是其较窄的能带隙导致电子跃迁能量阈值较低。自由基捕获实验验证了压电光催化的反应机理,并验证了BiFeO_(3)产生的压电场促进光催化反应进程的耦合效应。

Perovskite bismuth ferrite(BiFeO_(3))with narrower bandgap was synthesized by a hydrothermal method in response to the problems of high recombination rate of photoelectrons and holes with low absorption efficiency of visible spectrum during photocatalytic process.The results show that the degradation rate of indigo carmine reaches 97.6%in 15 min of the best-performed BiFeO_(3)sample synthesized at a NaOH concentration of 8 mol/L under the synergic effect of ultrasound and illumination.The fitted first-order reaction rate constant is 0.2036 min^(−1),which is attributed to its lower electron-leap energy threshold by narrower bandgap.The mechanism of piezo photocatalysis is clarified by free radical trapping experiments and the synergistic effect that the piezoelectric field of BiFeO_(3)promotes the photocatalytic process is verified.