铌酸钾的合成及其光催化性能

以草酸铌和醋酸钾为原料,加水研磨干燥后得到前驱体,前驱体分别在500℃和800℃焙烧3 h合成高纯相和高结晶度的铌酸钾粉末。红外光谱分析表明,草酸铌和醋酸钾发生离子交换反应生成前驱体KNbO(C_2O_4)_2]·xH_2O。500℃合成的铌酸钾颗粒粒径约50 nm,800℃合成的颗粒粒径在100 nm以上。以制备的铌酸钾粉末为光催化剂,在高压汞灯照射下,对亚甲基蓝溶液进行光催化降解。实验表明,500℃焙烧合成的铌酸钾粉末具有光催化性能,而800℃焙烧合成的不具有催化性能。催化动力学分析表明,亚甲基蓝溶液的光催化降解反应符合一级动力学方程。

Synthesis of potassium niobate and its photocatalytic properties

The precursor was obtained by grinding the mixture of niobium oxalate and potassium acetate with water and then being dried. Potassium niobate powders with high purity and crystallinity were prepared by calcining the precursor at 500 ℃ and 800 ℃ for 3 h. IR analysis indicated that there was an ion exchange reaction happened between niobium oxalate and potassium acetate and the precursor K NbO（ C204 ） 2 ] · xH2O was produced. The particle sizes of potassium niobate of about 50 nm and over 100 nm were attained at 500 ℃ and 800 ℃, respectively. Methylene blue solution was degraded using potassium niobate powder as the photocatalyst under the irradiation of high pressure mercury lamp. The experiment results showed that potassium niobate powders calcined at 500 ℃had the photocatalytic properties, and at 800 ℃ did not. The analysis results of catalytic dynamics showed that the photocatalytic degradation reaction of methylene blue solution fitted first-order kinetics equation.