Detection of Cr(VI) in agricultural products by photoelectrochemical sensor based on SnS/Bi2MoO6

Firstly, Bi2MoO6, SnS and SnS/Bi2MoO6-X (X = m(SnS)/m(Bi2MoO6), 1.66%, 2.26%, 3.32%) were synthesized through hydrothermal and agitation method. Subsequently, the morphology, structure and visible light absorption range of these materials were studied by a series of physical characterizations. The results show that the SnS/Bi2MoO6-X have a wider visible light absorption range and significantly higher separation efficiency of photogenerated carriers compared with the pure Bi2MoO6 and SnS. Among composites, SnS/Bi2MoO6-2.26% exhibits the best visible light absorption rate and carrier transfer efficiency. Furthermore, PEC tests suggest that SnS/Bi2MoO6-X composites exhibit higher PEC responses, and SnS/Bi2MoO6-2.26% has the strongest PEC activities. In addition, the PEC sensor based on SnS/Bi2MoO6-2.26% shows a lower detection limit (0.122 μM, S/N = 3) and a wider detection range (0.5 ∼ 310 μM) for Cr (VI). Meanwhile, the PEC sensor displays a good consistency in the detection results of Cr (VI) in lake, soil and agricultural products.