Fabrication of Ag@Co-Al Layered Double Hydroxides Reinforced poly(o-phenylenediamine) Nanohybrid for Efficient Electrochemical Detection of 4-Nitrophenol, 2,4-Dinitrophenol and Uric acid at Nano Molar Level

Abstract

In this paper, Co-Al layered double hydroxides (LDHs), Co-Al LDHs/poly(o-phenylenediamine) (PoPD) and Ag nanoparticles decorated Co-Al LDHs/PoPD (Ag@Co-Al LDH/PoPD) samples were prepared. The as-prepared samples were characterized by XRD, Raman, XPS, FT-IR, DRS-UV-Vis, PL and TGA techniques. The salient features of morphology and size of the samples were determined using FESEM, and HR-TEM. Then, the samples were coated on glassy carbon electrode (GCE) and employed for sensing of 4-nitrophenol (4-NP), 2,4-dinitrophenol (2,4-DNP)) and uric acid (UA). It was found that Ag@Co-Al LDH/PoPD/GCE showed superior electrochemical sensing behaviour than other modified electrodes. It exhibits the detection limit (DL) of 63 nM, 50 nM and 0.28 µM for 4-NP, 2,4-DNP and UA respectively.

Bi2O3 Nanoparticles Decorated Carbon Nanotube: An Effective Nanoelectrode for Enhanced Electrocatalytic 4-Nitrophenol Reduction

“…Furthermore, the Ni based nanocomposite, MgFe 2 O 4 NPs proved to be a good electrocatalyst for 4nanoparticles (NPs) reduction (Baby et al, 2019;Mejri et al, 2019). Carbon nanotubes decorated with metals like Pt, Pd, Ag, monometallic-Au, and bimetallic-Au show excellent electrocatalytic activity toward nitrophenols (Liu et al, 2015;Umar et al, 2016;Sun et al, 2017;Dhanasekaran et al, 2019;Ding et al, 2019), but their low earth abundance and high cost inhibits their practical applicability. In order to address these issues researchers have proposed alternative approaches including replacing the precious metals with non-noble metals or producing metal free systems with high stability and cost effectiveness.…”

Synthesis of Layered Double Hydroxides and TiO2 Supported Metal Nanoparticles for Electrocatalysis

“…A recent report where Ag was immobi- was shown to reduce 4-NP at a low potential (À 0.3 V vs SCE) in aqueous buffer environment. [9] Liguang et al also reported a highly recyclable hybrid material, xCu-LDH/rGO, which catalyses NaBH 4 mediated 4-NP reduction. [60] Haiqing et al reported a Pd/ CNT composite as highly efficient catalyst.…”

“…LDHs often exhibit a huge surface area and pore volume, which enables them to be used in surface catalysis [7] . Currently, LDHs are widely explored in several applications such as anion exchange, [8] electrochemical sensors [9] and as catalysts in water treatment [10] . The constant increase in the number of toxic organic compounds in the environment, mainly from pharmaceutical and pigments industry has raised a lot of attention over the years.…”

Rationally Designed Ag@polymer@2-D LDH Nanoflakes for Bifunctional Efficient Electrochemical Sensing of 4-Nitrophenol and Water Oxidation Reaction

“…4-NP (p-nitrophenol; P-NP or 4-NP) is one kind of severely toxic or explosive compound with substituted phenols. 14 Many of the environmental councils recommend the water quality parameters be set to a maximum level concentration of 4-NP in drinking water. The United States Environmental Protection Agency (US EPA) has permitted the limit of 4-NP in drinking water at 60 ppb (∼0.43 μM), the European Commission suggested that the maximum limit be 0.…”

“…16,17 4-NP induces methemoglobin formation, which is harmful and damages the central nervous system, liver, kidney, and blood because of its prospective carcinogenicity and mutagenicity at trace levels. 14 Among them, removing 4-NP from wastewater is an important and urgent environmental issue. Thus, the electrochemical approches are prefered to avoid expensive instrumentation, time-consuming progression, nonspecificity, and pretreatment for real-life samples and the traditional mark analytical methods like chromatography, spectrophotometry, HPLC, polarography, and capillary zone electrophoresis.…”