High Performance Electrocatalyst Based on MIL‐101(Cr)/Reduced Graphene Oxide Composite: Facile Synthesis and Electrochemical Detections

Abstract

In this work, a Cr-based MOF (MIL-101(Cr))/reduced grapheme oxide(rGO) electrocatalyst was prepared through a one-pot hydrothermal method. The obtained composite was characterized via scanning electron microscopy, transmission electron microscopy, X-ray diffraction and other standard techniques. Electrochemical methods were adopted to study the electrocatalytic ability of the composite. The results imply that, compared to the single components, it exhibits higher electrocatalytic activity for the reduction of metronidazole and stripping of Cd 2 + and Pb 2 + . Optimizing the ratio of MIL-101(Cr) and rGO, an electrochemical sensor was prepared using MIL-101 (Cr)/rGO-20 and used for detection of metronidazole, Cd 2 + and Pb 2 + , respectively. The linear range for metronidazole can be divided in two parts, i. e. from 0.5 to 200 mM and from 200 to 900 mM. The limit of detection is 0.24 mM (S/N = 3, n = 10). Likewise, it also exhibits a wide linear range from 0.05 to 6.0 mM for the detection of Cd 2 + and Pb 2 + . The corresponding detection limits are found to be 5.2 nM and 3.0 nM (S/N = 3, n = 10), respectively. The proposed sensor also possesses superb selectivity, reproducibility, stability and can be applied to detect real samples with desired recovery rates. In addition, the possible reduction mechanism of metronidazole and adsorption mechanism of Cd 2 + and Pb 2 + were further discussed simply in this work.[a] J.

Metal−Organic Frameworks toward Electrochemical Sensors: Challenges and Opportunities

“…For example, Ma and coworkers found that the electrochemically active polyaniline polymerized in the pores of UiO‐66‐NH 2 can exhibit a much better electrochemical activity for the detection of cadmium ions compared to both the pristine polyaniline and UiO‐66‐NH 2 (Figure (c)) . In addition to Zr‐MOFs, MIL‐101(Cr) was also chosen to prepare the MOF‐based composite with reduced graphene oxide, and the resulting composite can be applied for electrochemical detections of cadmium and lead ions . Table lists the selected studies on MOF‐based materials for electrochemical sensing applications published recently.…”

Photo-electrochemical detection of dopamine in human urine and calf serum based on MIL-101 (Cr)/carbon black

“…In Fig. 1A, MIL-101 (Cr) exhibited a typical octahedral structure, and the diameter of particles was between 400 and 600 nm [16,22]. The TEM image of MIL-101 (Cr) is shown in Fig.…”

“…For example, Cao et al used Cu-BTC MOF/g-C 3 N 4 to prepare a glyphosate photo-electrochemical sensor for the detection of glyphosate [15]. Gu et al used reduced graphene oxide combined with Cr-MOF to enhance the electro-catalytic activity of MOF for the detection of heavy metal ions [16].…”

“…Among a large number of conductive materials, carbonbased materials are used to enhance the conductivity of MOFs, such as graphene, carbon nanotubes, and carbon black (CB) [16,17]. For example, CB not only has high conductivity but also is cheaper than graphene and carbon nanotubes, which is widely worked as the electron bridge to accelerate the transfer of electrons from catalyst to electrode.…”

Recent Advances in Porphyrin-Based Materials for Metal Ions Detection

“…MOF materials have the advantages of large specific surface area, many adsorbable sites, strong designability, and functional modification [ 103 , 104 , 105 ]. They are used in the fields of chemical sensing [ 106 ], electrochemical detection [ 107 ], catalysis [ 108 ], gas adsorption and separation [ 109 ], and drug loading [ 110 ]. Continuous progress has been made and has received widespread attention in recent decades.…”