Xu Kebin, Li Ying, Li Min
School of Metallurgy, Northeastern University, Shenyang 110819, People's Republic of China.
Liaoning Key Laboratory for Metallurgical Sensor Material and Technology, Shenyang 110819, People's Republic of China.
ACS Omega. 2021 May 20;6(21):13795-13801. doi: 10.1021/acsomega.1c00195. eCollection 2021 Jun 1.
Determination of phosphate ions in aqueous solutions attracts a great deal of interest in the areas of environment, medicine, and agriculture. As phosphoric acid is a poly basic acid, the different forms of existence at different pH result in direct determination facing a big challenge. Herein, we reported a potentiometric phosphate ion sensor based on a surface-modified tungsten electrode. Pure tungsten was electrodeposited at a constant potential of 0.2 V versus Ag|AgCl in NaHPO. WO and HOPW·HO were electrodeposited on the surface of the tungsten electrode. The modified tungsten electrode was used as a working electrode in a two-electrode system to detect the concentration of phosphate ions in aqueous solutions. The detection limit of the modified tungsten electrode for phosphate ions is 10 M from pH 7 to pH 8 and 10 M from pH 9 to pH 10. It has good selectivity to other common anions. The long-term monitoring experiment showed that the potential fluctuation was less than ±3 mV in 24 h. Compared to conventional determination methods, the current phosphate ion sensor showed a close value in a real sample. The mechanism of phosphate ion response was investigated in detail. This sensor possesses advantages of simple manufacture, low cost, a wide pH range for detecting, and good selectivity.
水溶液中磷酸根离子的测定在环境、医学和农业领域引起了广泛关注。由于磷酸是一种多元酸，在不同pH值下的不同存在形式使得直接测定面临巨大挑战。在此，我们报道了一种基于表面修饰钨电极的电位型磷酸根离子传感器。在NaHPO中，相对于Ag|AgCl，在0.2 V的恒定电位下电沉积纯钨。将WO和HOPW·HO电沉积在钨电极表面。修饰后的钨电极在两电极系统中用作工作电极，以检测水溶液中磷酸根离子的浓度。修饰后的钨电极对磷酸根离子的检测限在pH 7至pH 8时为10 M，在pH 9至pH 10时为10 M。它对其他常见阴离子具有良好的选择性。长期监测实验表明，在24小时内电位波动小于±3 mV。与传统测定方法相比，当前的磷酸根离子传感器在实际样品中显示出相近的值。详细研究了磷酸根离子的响应机制。该传感器具有制作简单、成本低、检测pH范围宽和选择性好等优点。
