Bridging Component Strategy in Phosphomolybdate-Based Sensors for Electrochemical Determination of Trace Cr(VI)

作者：Jing-Yan He, Hao‐Xue Bi, Yuqing Liu, Meng-Si Guo, Wenting An, Yuan‐Yuan Ma, Zhangang Han · 发表于：Inorganic Chemistry · 年份：2023 · DOI：10.1021/acs.inorgchem.3c03841 · 被引用次数：24 · 研究领域：Polyoxometalates: Synthesis and Applications、Metal-Organic Frameworks: Synthesis and Applications、Chemical Synthesis and Characterization

Rapid and sensitive electrochemical determination of trace carcinogenic Cr(VI) pollutants remains an urgent and important task, which requires the development of active sensing materials. Herein, four cases of reduced phosphomolybdates with formulas of the (H 2 bib) 3 [Zn(H 2 PO 4 )] 2 {Mn[P 4 Mo 6 O 31 H 7 ] 2 }·6H 2 O ( 1 ), (H 2 bib) 2 [Na(H 2 O)] 2 [Mn(H 2 O)] 2 {Mn[P 4 Mo 6 O 31 H 6 ] 2 }·5H 2 O ( 2 ), (H 2 bib) 3 [Mo 2 (μ 2 -O) 2 (H 2 O) 4 ] 2 {Ni[P 4 Mo 6 O 31 H 2 ] 2 }·4H 2 O ( 3 ), and (H 2 bib) 2 {Ni[P 4 Mo 6 O 31 H 9 ] 2 }·9H 2 O ( 4 ) (bib = 4,4′-bis(1-imidazolyl)-biphenyl) were hydrothermally synthesized under the guidance of a bridging component strategy, which function as effective electrochemical sensors to detect trace Cr(VI). The difference of hybrids 1 – 4 is in the inorganic moiety, in which the reduced phosphomolybdates {M[P 4 Mo V 6 O 31 ] 2 } (M{P 4 Mo 6 } 2 ) exhibited different arrangements bridged by different cationic components ({Zn(H 2 PO 4 )} subunit for 1, [Mn 2 (H 2 O) 2 ] 4+ dimer for 2, and [Mo V 2 (μ 2 -O) 2 (H 2 O) 4 ] 6+ for 3 ). As a result, hybrids 1 and 3 display noticeable Cr(VI) detection activity with low detection limits of 14.3 nM (1.48 ppb) for 1 and 6.61 nM (0.69 ppb) for 3 and high sensitivities of 97.3 and 95.3 μA·mM –1, respectively, which are much beyond the World Health Organization’s detection threshold (0.05 ppm) and superior to those of the contrast samples (inorganic Mn{P 4 Mo 6 } 2 salt and hybrid 4 ), even the most rep...