One-step hydrothermal treatment to fabricate Bi2WO6-reduced graphene oxide nanocomposites for enhanced visible light photoelectrochemical performance.

Abstract

Considering that ultraviolet light may cause the denaturation of biomaterials, searching for and engineering innovative and advanced nanomaterials with excellent photoelectrochemical properties under visible light illumination are of great significance in the fundamental understanding and application of photoelectrochemical (PEC) sensors. As a widely applied visible light response material, the applications of Bi2WO6 in PEC fields were restricted because of the rapid recombination of photoinduced electron-hole pairs. In this work, Bi2WO6 functionalized reduced oxide (Bi2WO6-rGO) nanocomposites (NCs) were prepared by a one-step solvothermal method. After optimizing the content of rGO, the Bi2WO6-rGO2.94% NCs displayed enhanced photocurrent intensity (the starting mass ratios of GO to Bi2WO6 = 0.0294), which was nearly 2.7-fold compared to that of pure Bi2WO6 nanoparticles because of the separation of the photoinduced carriers and the enhancement of visible light absorption. Based on the coupling of Pb2+-induced allosteric transition of G-quadruplex DNAzyme and the enzymatic biocatalytic precipitation (BCP), Bi2WO6-rGO2.94% NCs were applied in the construction of a novel PEC sensor for the determination of Pb2+. The as-fabricated PEC sensor exhibited good anti-interference ability and a good linear relationship was obtained between the photocurrent intensity and the logarithm of the Pb2+ concentration over a concentration range from 0.01 to 50 μM and with a detection limit of 3.3 nM (S/N = 3), indicating that Bi2WO6-rGO NCs would be promising materials for PEC sensing.