Pei-Hua Li

Bio: Pei-Hua Li is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Catalysis & Chemistry. The author has an hindex of 9, co-authored 18 publications receiving 205 citations. Previous affiliations of Pei-Hua Li include University of Science and Technology of China.

Electrochemical spectral methods for trace detection of heavy metals: A review

Abstract: The contamination containing trace heavy metal ions (HMIs) has received great attentions, as it poses serious threats to ecological system and human health. Hence, the developments of a rapid technology for the real-time and on-line detection of HMIs are of significance. Considering the drawbacks of singular spectral method and electrochemical method, electrochemical spectral method has been proposed as a powerful analytical technology for the detection of trace HMIs because of its great sensitivity, anti-interference ability and super low limit of detection (LOD). As such, in this review, we primarily described the recent advances of representative electrochemical spectral methods and their applications, including electrochemical atomic absorption spectrometry (EC-AAS), electrochemical total reflection X-ray fluorescence and X-ray fluorescence (EC-TXRF/XRF), and electrochemical laser-induced breakdown spectroscopy (EC-LIBS). Additionally, we basically introduced the electrochemical preconcentration methods generally used prior to spectral methods, including electrodeposition and electroadsorption. Based on the overview of these methods, we also addressed up-to-date challenges of in-situ electrochemical spectral methods, for which additional researches are needed to carry out.

Highly sensitive electrochemical detection of Pb(II) based on excellent adsorption and surface Ni(II)/Ni(III) cycle of porous flower-like NiO/rGO nanocomposite

Abstract: Herein, combining the good catalysis of NiO with high adsorption and conductivity of reduced graphene oxide (rGO), the electrochemical sensing interface was constructed using the porous flower-like NiO/rGO nanocomposite modified glassy carbon electrode (GCE). The result of Pb(II) detection was obtained with high sensitivity of 92.81 μM μA−1 and low detection limit of 0.01 μM by square wave anodic stripping voltammetry (SWASV). The reasonable sensitive mechanism for enhancing electrochemical performance is that the excellent adsorption capacity and Ni(II)/Ni(III) cycle on surface of NiO/rGO nanocomposite could improve the electrochemical detection signal. Furthermore, the proposed method achieved the high anti-interference on the determination of Pb(II) in the co-existence of Cd(II), Cu(II), Hg(II). The excellent stability and reproducibility were also confirmed by repeatedly test. In addition, the concentration of Pb(II) in real water samples from Taochong wastewater treatment plant in Hefei city were analyzed and calculated accurately. These results indicates that the NiO/rGO nanocomposite as a promising electrode modifier could be potentially applied in electrochemical sensor for detecting Pb(II).

Ultra-Sensitive and Selective Detection of Arsenic(III) via Electroanalysis over Cobalt Single-Atom Catalysts

Abstract: Achieving highly sensitive and selective detection of trace-level As(III) and clarifying the underlying mechanism is still a intractable problem. The electroanalysis of As(III) relies on the electrocatalytic ability of the sensing interface. Herein, we first adopt single-atom catalysts as the electrocatalyst in As(III) detection. Cobalt single-atoms anchored on nitrogen-doped carbon material (Co SAC) were found to have an extraordinary sensitivity of 11.44 μA ppb-1 with excellent stability and repeatability, which so far is the highest among non-noble metal nanomaterials. Co SAC also exhibited a superior selectivity toward As(III) compared with some bivalent heavy metal ions (HMIs). Combining X-ray absorption spectroscopy (XAFS), density functional theory (DFT) calculation, and reaction kinetics simulation, we demonstrated that Co single atoms stabilized in N2C2 support serve as active sites to catalyze H3AsO3 reduction via the formation of Co-O hybridization bond, leading to a lower energy barrier, promoting the breakage of As-O bonds. Importantly, the first electron transfer is the rate-limiting step of arsenic reduction and is found to be more favorable on Co-SAC both thermodynamically and kinetically. This work not only expands the potential applicaiton of single-atom catalysts in the detection and treatment of As(III), but also provides atomic-level catalytic insights into HMIs sensing interfaces.

Metal Replacement Causing Interference in Stripping Analysis of Multiple Heavy Metal Analytes: Kinetic Study on Cd(II) and Cu(II) Electroanalysis via Experiment and Simulation.

Abstract: Although it has been recognized that the interference between heavy metal ions (HMIs) becomes a severe problem for the simultaneous electroanalysis of multiple HMIs, the factor leading to the interference is still difficult to identify, due to the limited understanding of the electroanalytic kinetics. In this work, a kinetic model is built for the electroanalysis of HMIs, and the electroanalytic results are simulated for Cd(II), Cu(II), and their mixture as examples for the interference investigation. The mutual interference between Cd and Cu is observed on the glassy carbon electrode. By applying the kinetic model, the replacement of deposited Cd by Cu(II) at the codeposition stage is regarded as the main reason for the interference, and the corresponding suggestion for selecting suitable electrode materials to avoid such interference is also provided.

Sensitive and interference-free electrochemical determination of Pb(II) in wastewater using porous Ce-Zr oxide nanospheres

Abstract: Herein, combined the synergetic effects and excellent adsorption of binary oxides, a novel sensor interface was designed by using porous Ce-Zr oxide nanospheres modified glassy carbon electrode (Ce-Zr oxide/GCE), which has successfully realized high sensitivity and anti-interference detection of Pb(II). The electrochemical determination of Pb(II) has been investigated by square wave anodic stripping voltammetry (SWASV) range from 0.02 to 0.5 μM, and a high sensitivity per unit area of 1666.02 μA μM−1 cm−2 was obtained with a limit of detection of 0.006 μM (3σ method). The enhancement of Pb(II) stripping signal is attributed to the excellent adsorption performance of porous Ce-Zr oxide nanospheres, which has been confirmed with X-ray photoelectron spectroscopy (XPS). Importantly, Ce-Zr oxide/GCE possesses highly anti-interference ability against the influence of Hg(II), Cd(II), Cu(II), and Zn(II) in the determination of Pb(II). Meanwhile, the remarkable stability and reproducibility were obtained. Finally, the accurate analysis of Pb(II) in wastewater collected from Wangtang sewage disposal plant was achieved. These results indicate that porous Ce-Zr oxide nanospheres are identified as promising modifier for the reliable and accurate determination of Pb(II).

Emerging of Heterostructure Materials in Energy Storage: A Review.

Abstract: With the ever-increasing adaption of large-scale energy storage systems and electric devices, the energy storage capability of batteries and supercapacitors has faced increased demand and challenges. The electrodes of these devices have experienced radical change with the introduction of nano-scale materials. As new generation materials, heterostructure materials have attracted increasing attention due to their unique interfaces, robust architectures, and synergistic effects, and thus, the ability to enhance the energy/power outputs as well as the lifespan of batteries. In this review, the recent progress in heterostructure from energy storage fields is summarized. Specifically, the fundamental natures of heterostructures, including charge redistribution, built-in electric field, and associated energy storage mechanisms, are summarized and discussed in detail. Furthermore, various synthesis routes for heterostructures in energy storage fields are roundly reviewed, and their advantages and drawbacks are analyzed. The superiorities and current achievements of heterostructure materials in lithium-ion batteries (LIBs), sodium-ion batteries (SIBs), lithium-sulfur batteries (Li-S batteries), supercapacitors, and other energy storage devices are discussed. Finally, the authors conclude with the current challenges and perspectives of the heterostructure materials for the fields of energy storage.

Recent Advances of Porous Graphene: Synthesis, Functionalization, and Electrochemical Applications.

Abstract: Graphene is a 2D sheet of sp2 bonded carbon atoms and tends to aggregate together, due to the strong π-π stacking and van der Waals attraction between different layers. Its unique properties such as a high specific surface area and a fast mass transport rate are severely blocked. To address these issues, various kinds of 2D holey graphene and 3D porous graphene are either self-assembled from graphene layers or fabricated using graphene related materials such as graphene oxide and reduced graphene oxide. Porous graphene not only possesses unique pore structures, but also introduces abundant exposed edges and accelerates mass transfer. The properties and applications of these porous graphenes and their composites/hybrids have been extensively studied in recent years. Herein, recent progress and achievements in synthesis and functionalization of various 2D holey graphene and 3D porous graphene are reviewed. Of special interest, electrochemical applications of porous graphene and its hybrids in the fields of electrochemical sensing, electrocatalysis, and electrochemical energy storage, are highlighted. As the closing remarks, the challenges and opportunities for the future research of porous graphene and its composites are discussed and outlined.

Metal and metal oxide nanoparticles in the voltammetric detection of heavy metals: A review

Abstract: Most heavy metal ions are known to be toxic and carcinogenic when present in high amounts Thus, rapid and reliable on-site detection of these ions is crucial Voltammetry is a highly sensitive electrochemical method that has been widely used for heavy metal detection offering the advantages of sensitivity and rapidity On the other hand, nanoparticles offer the advantages of high surface area and high selectivity Thus, this review aims to highlight the application of metallic and metallic oxide nanoparticles for the voltammetric detection of heavy metals The nanoparticles used were either applied solely on the electrode or as modifiers with various materials In all cases, the synthesized devices showed an enhanced analytical performance, such that the limits of detection were lowered and the sensitivities were increased as compared to voltammetric systems not using nanoparticles Moreover, the applicability of some of these systems was investigated in real samples