Development of Palladium on Bismuth Sulfide Nanorods as a Bifunctional Nanomaterial for Efficient Electrochemical Detection and Photoreduction of Hg(II) Ions

Abstract

A nanocomposite containing palladium nanoparticles embedded on bismuth sulfide nanorods (Pd@Bi2S3) was synthesized based on a solvothermal method. The structural features, composition, and morphology were characterized by XRD, FT-IR, FE-SEM-EDS, FE-TEM, HAADF-STEM, XPS, N2 physisorption, and UV–vis. Further electrochemical measurements by EIS, CV, DPV, and LSV techniques were done. It revealed that Pd@Bi2S3/GCE were exploited as electrochemical sensors for the detection of toxic mercuric ions (Hg2+), which provides a wide linear range of 0.049–445 μM, excellent sensitivity of 1.17 μA μM–1 cm–2, and detection limit of 13.5 nM. The modified electrode has also been successfully applied for the detection of Hg2+ in sea fish, river fish, and water samples. The Pd@Bi2S3/GCE signifies a robust, usability, and highly effective method for trace level detection of Hg2+ ions. Furthermore, these Pd@Bi2S3 bifunctional catalysts were discovered to have good photoreduction activity for Hg2+ ions upon the visible-light irradiation.

Graphitic Carbon Nitride Nanosheets Decorated with Strontium Tungstate Nanospheres as an Electrochemical Transducer for Sulfamethazine Sensing

“…The following eq was used to compute the rates of charge transfer coefficient ( K s ) of bare GCE, SrWO 4 /GCE, g-C 3 N 4 /GCE, and SrWO 4 /g-C 3 N 4 /GCE R CT = italicRT n 2 F 2 K normals C where “ K s ” stands for the charge transfer rate, “ n ” stands for the number of electrons, “ C ” stands for a concentration of [Fe(CN) 6 ] 4–/3– , and “ R , T , and F ” represent their specific meanings. , The rate constant ( K s ) value of SrWO 4 /g-C 3 N 4 /GCE was determined to be 5.13 × 10 –7 cm/s, indicating that SrWO 4 /g-C 3 N 4 /GCE has a higher catalytic activity than other modified and unmodified electrodes such as bare GCE (1.74 × 10 –7 cm/s), SrWO 4 /GCE (4.14 × 10 –7 cm/s), and g-C 3 N 4 /GCE (2.89 × 10 –7 cm/s). Finally, the above electrical characteristic results confirmed that the SrWO 4 /g-C 3 N 4 /GCE composite possesses a high active surface, higher current density, quicker electron transfer, lower Δ E p , and higher charge transfer rate than SrWO 4 /GCE and g-C 3 N 4 /GCE.…”

Reinforcement of Visible-Light Harvesting and Charge-Transfer Dynamics of BiVO4 Photoanode via Formation of p–n Heterojunction with CuO for Efficient Photoelectrocatalytic Water Splitting

“…To overcome these issues, various strategies, namely, doping of impurity, loading of cocatalyst, Schottky junction, and formation of p–n or n–n heterostructures with other semiconductors have been developed. − Among them, the formation of a p–n heterojunction is a promising way to enhance PEC performance of the BiVO 4 photoanode. The formation of the p–n junction causes IEF at the interface between two semiconductors, and therefore, it promotes electron–hole pair separation and reduces charge recombination. − For example, Ye et al reported a BiOI-BiVO 4 p–n junction electrode for water splitting application, and they showed a 3-fold higher PEC performance than BiVO 4 by reducing electron–hole recombination.…”

Tetrahedral DNA-directed core-satellite assembly as SERS sensor for mercury ions at the single-particle level

“…The lowest concentration for quantitative detection of Hg 2+ by this method corresponded to 1 nM, which is lower than the allowable maximum residue limit of Hg 2+ (10 nM) in drinkable water as per the United States Environmental Protection Agency (USEPA). 33,38 Compared with the previously reported methods for Hg 2+ measurement, [39][40][41][42][43] the proposed strategy for Hg 2+ shows much higher detection sensitivity (Table S2 †).…”