Synthesis of 3D hierarchically porous carbon@Bi-BiOCl nanocomposites via in situ generated NaCl crystals as templates for highly sensitive detection of Pb2+ and Cd2+

Abstract A facile, environmentally friendly and scalable method was reported to synthesize highly dispersed Bi-BiOCl nanoparticles dispersed on three dimensional porous networks of carbon nanosheet using NaCl as template and citric acid as carbon source. The novel 3D architecture demonstrated easily accessible porous structure, large surface area, superior electrical conductivity and good mechanical flexibility, which was capable of accelerating three dimensional diffusion of ions and transport of electrons in the whole electrode. In addition, the highly dispersed Bi-BiOCl nanoparticles on the carbon backbone could facilitate the utilization of these active materials in electrochemical sensing. Under optimized conditions, Bi-BiOCl@C-3 modified glassy carbon electrode exhibited preeminent electroanalytical performance for the simultaneous sensing of Pb 2+ and Cd 2+ in the linear range of 1–60 μg L −1 , with sensitivities of 0.38 and 0.49 μA L μg −1 , respectively. The developed protocol has shown limits of detection ( S/N  = 3) of 0.2 and 0.4 μg L −1 for Pb 2+ and Cd 2+ , respectively, which complies with the limits set by the World Health Organization (WHO). Moreover, high resistance to interference, long-term stability, good reproducibility and satisfactory testing recoveries were realized for real water sample, suggesting that the proposed 3D Bi-BiOCl@C-3 nanocomposite could be utilized as a promising candidate for the fabrication of high-performance electrochemical sensor.