Electrochemical detection of 2-nitrophenol using a heterostructure ZnO/RuO₂ nanoparticle modified glassy carbon electrode

Abstract

A highly selective chemisensor for 2-nitrophenol detection was fabricated using ZnO/RuO 2 nanoparticles (NPs) synthesized by impregnation method. The as-synthesized NPs were characterized through UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDS), FTIR and X-ray diffraction (XRD). A glassy carbon electrode was modified with as-synthesized ZnO/RuO 2 nanoparticles and utilized as a chemical sensor for the detection of 2-nitrophenol. The fabricated sensor exhibited excellent sensitivity (18.20 mA mM À1 cm À2 ), good reproducibility, short response time (8.0 s.), the lowest detection limit (52.20 AE 2.60 pM) and long-term stability in aqueous phase without interference effects. Finally, the fabricated sensor was validated as a 2-NP probe in various environmental water samples at room conditions. Fig. 2 Crystallinity and photo-sensitivity, (A) powder X-ray diffraction (XRD) of ZnO/RuO 2 NPs, (B) UV-vis absorption spectrum of ZnO/RuO 2 NPs, and (C) FTIR analysis: (a) ZnO; (b) ZnO/RuO 2 and (c) RuO 2 . 126 | RSC Adv., 2020, 10, 122-132 This journal isFig. 3 Structural morphology and elemental analysis of ZnO/RuO 2 NPs, (A and B) low and high magnified FESEM images, (C and D) elemental and structural analysis of ZnO/RuO 2 NPs, by EDS.This journal is

A novel highly selective electrochemical chlorobenzene sensor based on ternary oxide RuO2/ZnO/TiO2 nanocomposites

“…Similar tendencies of electrochemical responses to detect different toxicants have been reported earlier. 16,[92][93][94] This result reected that the conductivity of the fabricated RuO 2 /ZnO/TiO 2 NC-modied electrode increased with the enrichment of CBZ concentration, as excess free electrons were provided to the conduction bands of ZnO and TiO 2 NPs in the synthesized RuO 2 /ZnO/TiO 2 NCs.…”

“…In addition, any change in interfacial resistance due to the formation of a heterojunction results in improved performance of sensors. 43 Composite metal oxides have already been utilized for the reliable and selective detection of numerous toxicants in the gaseous phase, such as ZnO/SnO 2 nanobers for ethanol, 44 ZnO/Cr 2 O 3 nanorods and ZnO/In 2 O 3 nanobers for trimethylamine, 45,46 V 2 O 5 doped ZnO NCs for phenylhydrazine, 17 MgO/ ZnO composite for H 2 O 2 , 47 and RuO 2 /ZnO NCs for 2-nitrophenol 16 as reported earlier. Similarly, TiO 2 is another n-type semiconductor with a wide optical band gap, and it has good stability and opto-electro-chemical properties.…”

“…As a result, the assembled sensor experienced intense electrochemical responses as the comparable statement has been reported previously in the detection of various chemicals and bio-chemicals in an electrochemical approach. 16,90,91 In electrochemical detection, the observed current was assessed on the surface of a thin layer of NCs on the GCE and the delay time in electrometer was constantly set as 1 s throughout the investigation.…”

“…However, these techniques face different critical limitations including complicated fabrication, high cost, time consumption in sample pretreatment including separation and the prolonged data analysis. Over the past decades, electrochemical (EC) methods have received excessive attention in various diagnoses including clinical, [13][14][15] environmental, 16,17 biological, 18 pharmaceutical, and quality control during food processing. 19 Among the EC methods, the electrochemical approach has drawn signicant attention of researchers due to its high sensitivity, good selectivity, inexpensive instruments, ease of operation, simple pretreatment of samples, and faster analysis.…”

Nickel hexacyanoferrate film coated pencil graphite electrode as sensor and electrode material for environment and energy applications

“…Recently, a significant attention has been received on electrochemical techniques to overcome these restrictions [23][24][25][26][27] because of their more sensitivity, low-cost, user-friendly, reproducibility, lowlimit of detection, and selectivity. [28][29][30] The NP detection using conventional electrodes were inadequate due to their poor electrocatalytic efficiencies and electrode fouling. Therefore, various modification procedures recently have been carried out to improve their electrocatalytic performance towards the detection of NP isomers such as metal (hybrid inorganic-organic/Pt and CuNP/Au), 31,32 diamond, 33 RGO/Au/GCE 34 and AuNp/ graphite, 35 nanoporous gold, 36 macroporous imprinted polymer, 37 porous copper, 38 multi-walled carbon nanotubes 39 and bismuth film.…”