Bismuth nanoparticles decorated vertically arranged graphene as flexible electrodes for highly efficient detection of Pb(II) ions in water

Abstract

Plasma enhanced chemical vapor deposition(PECVD) system was used to prepare a vertically arranged graphene (VG) thin-film materials. Bismuth nanoparticles (BiNPs) of different sizes were loaded on VG films by physical vapor deposition (PVD) technique to obtain a BiNPs decorated VG screen-printed electrodes (BiNPs/VG-SPEs) with high sensitivity. The morphology and electrochemical properties of VG-SPE and three BiNPs/VG-SPEs with different sizes of BiNPs were studied by various interface characterization and electrochemical measurements. Compared with pristine VG-SPEs, BiNPs/VG-SPEs demonstrated better electrochemical performance. The electrode with smaller size of BiNPs has the larger electrochemical active area and higher electron transfer efficiency, achieving better electrochemical response to Pb(II) ions. Therefore, VG-SPE with smallest size of BiNPs (4.6 ± 0.5 nm) was utilized to detect Pb(II) ions in aqueous solution. Under the optimized conditions, BiNPs/VG-SPE showed a broader linear concentration range (5–200 μg/L) with a low detection limit (0.15 μg/L). This sensor was also successfully applied for detection of Pb(II) ions in groundwater and tap water. Recovery rates ranged from 96.2 to107.2 % with a relative standard deviation (RSD) less than 6.8 %. It also has good anti-interference and repeatability. Our results provide a promising sensor technique for efficient and rapid in situ monitoring of Pb(II) ions in aquatic environments.