Flower-like Bi₂S₃ nanostructures grown on nitrogen-doped reduced graphene oxide for electrochemical determination of hydrogen peroxide

Kumar, Deivasigamani Ranjith,Kesavan, Srinivasan,Baynosa, Marjorie Lara,Nguyen, Van Quang,Shim, Jae-Jin Elsevier 2018 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.530 No.-

<P><B>Abstract</B></P> <P>This paper reports a facile solvothermal method for the synthesis of Bi<SUB>2</SUB>S<SUB>3</SUB> flower-like nanostructures grown <I>in situ</I> on a nitrogen-doped reduced graphene oxide (Bi<SUB>2</SUB>S<SUB>3</SUB>@N-G) surface. Thiourea was used as the nitrogen source and reducing agent for graphene oxide. The surface morphology of the as-prepared Bi<SUB>2</SUB>S<SUB>3</SUB>@N-G composites was analyzed by field emission scanning electron microscopy and transmission electron microscopy. The crystalline structure and surface chemical states were examined by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The as-prepared Bi<SUB>2</SUB>S<SUB>3</SUB>@N-G composite was deposited on a glassy carbon (GC) electrode, and the modified electrode was employed for the electrocatalytic detection of H<SUB>2</SUB>O<SUB>2</SUB>. The calculated diffusion coefficient and catalytic rate constant of the Bi<SUB>2</SUB>S<SUB>3</SUB>@N-G modified electrode were 4.9 × 10<SUP>−6</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> and 5671 M<SUP>−1</SUP> s<SUP>−1</SUP>, respectively. The Bi<SUB>2</SUB>S<SUB>3</SUB>@N-G/GC electrode demonstrated a wide concentration range for H<SUB>2</SUB>O<SUB>2</SUB>, from 10 to 42,960 μM, with a sensitivity of 0.1535 μA μM<SUP>−1</SUP> and an obtained limit of detection of 1.9 μM.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

3,5-Diamino-1,2,4-triazole@electrochemically reduced graphene oxide film modified electrode for the electrochemical determination of 4-nitrophenol

Kumar, Deivasigamani Ranjith,Kesavan, Srinivasan,Baynosa, Marjorie Lara,Shim, Jae-Jin Elsevier 2017 ELECTROCHIMICA ACTA Vol.246 No.-

<P><B>Abstract</B></P> <P>In this study, an eco-friendly benign method for the modification of electrochemically reduced graphene oxide (ERGO) on glassy carbon (GC) surface and electrochemical polymerized 3,5-diamino-1,2,4-triazole (DAT) film composite (pDAT@ERGO/GC) electrode was developed. The surface morphologies of the pDAT@ERGO/GC modified electrode were analyzed by field emission scanning electron microscopy (FESEM). FESEM images indicated that the ERGO supported pDAT has an almost homogeneous morphology structure with a size of 70 to 80nm. It is due to the water oxidation reaction occurred while pDAT@ERGO/GC fabrication peak at +1.4V leads to O<SUB>2</SUB> evolution and oxygen functional group functionalization on ERGO, which confirmed by X-ray photoelectron spectroscopy (XPS). In contrast, the bare GC modified with pDAT showed randomly arranged irregular bulky morphology structure compared to those of pDAT@ERGO/GC. Electrochemical reduction of graphene oxide was confirmed by Raman spectroscopy, XPS, and electrochemical impedance spectroscopy (EIS). The pDAT@ERGO/GC modified electrode was used for the electrochemical determination of 4-nitrophenol (4-NP). The 4-NP oxidation peak was observed at +0.25V, and the differential pulse voltammetry demonstrated wide concentration range (5–1500μM), high sensitivity (0.7113μA μM<SUP>−1</SUP>), and low limit of detection (37nM). Moreover, the pDAT@ERGO/GC electrode was applied to real water sample analysis by standard addition method, where in good recoveries (97.8% to 102.4%) were obtained.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Triazole film was formed on electrochemically reduced graphene oxide. </LI> <LI> pDAT@ERGO/GC was utilized for the electrochemical determination of 4-nitrophenol. </LI> <LI> pDAT@ERGO/GC electrode offered wide concentration and nanomolar detection limit. </LI> <LI> The fabricated electrode was employed in water sample analyses. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Flower-like Cu_1.8S nanostructures for high-performance flexible solid-state supercapacitors

Ranjith Kumar, Deivasigamani,Kesavan, Srinivasan,Baynosa, Marjorie Lara,Shim, Jae-Jin Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.448 No.-

<P><B>Abstract</B></P> <P>In wearable and portable electronic devices, small size, light weight, flexibility, and easy operability are necessary for energy storage systems, such as battery and supercapacitor. To improve the performance, high specific capacity and high energy and power densities are also required. In this study, flower-like Cu<SUB>1.8</SUB>S nanostructures are synthesized from a single source tris(thiourea)copper(I) chloride complex precursor. The different-sized Cu<SUB>1.8</SUB>S nanostructures with flower-like petal morphology are successfully synthesized by addition of capping agents such as sodium dodecyl sulfate (SDS) and ethylenediaminetetraacetic acid (EDTA) with ethylene glycol (EG) as a solvent. The petal thicknesses vary from 60 to 30 nm, resulting in the increase in its specific surface area. The as-prepared nanostructures are tested for their supercapacitor performances in KOH electrolyte medium. The EDTA-Cu<SUB>1.8</SUB>S electrode provides a high specific capacitance of 1050.0 F g<SUP>−1</SUP> as compared with SDS-Cu<SUB>1.8</SUB>S (773.0 F g<SUP>−1</SUP>) and EG-Cu<SUB>1.8</SUB>S (625.4 F g<SUP>−1</SUP>). Flexible solid-state symmetric supercapacitors are also fabricated from EDTA-Cu<SUB>1.8</SUB>S which deliver a high volumetric capacitance (4.5 F cm<SUP>−3</SUP>) and energy density (0.5 mWh cm<SUP>−3</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Flower-like Cu<SUB>1.8</SUB>S was synthesized from tris(thiourea)copper(I)chloride complex. </LI> <LI> Flower-like Cu<SUB>1.8</SUB>S with different petal morphology was prepared. </LI> <LI> A flexible SSC decorated with 3D flower-like Cu<SUB>1.8</SUB>S was prepared. </LI> <LI> Flower-like Cu<SUB>1.8</SUB>S SSC with thinner petal thickness showed high capacitance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Potentiodynamic formation of diaminobenzene films on an electrochemically reduced graphene oxide surface: Determination of nitrite in water samples

Kesavan, Srinivasan,Kumar, Deivasigamani Ranjith,Baynosa, Marjorie Lara,Shim, Jae-Jin Elsevier 2018 Materials science & engineering. C, Materials for Vol.85 No.-

<P><B>Abstract</B></P> <P>An electrode comprised of a polydiaminobenzene (p-DAB) film formed on electrochemically reduced graphene oxide (ERGO) on a glassy carbon (GC) (p-DAB@ERGO/GC) was fabricated using a potentiodynamic method for the sensitive and selective determination of nitrite in the presence of a common interference. The p-DAB@ERGO/GC film-modified electrode surfaces were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The film fabrication was initiated via the NH<SUB>2</SUB> groups of DAB, which was confirmed by XPS from the peaks corresponding to NH (396.7eV), NH (399.4eV), NN (400.2eV), and N<SUP>+</SUP>H (402.2eV). The Raman spectra revealed the characteristic D and G bands at 1348 and 1595cm<SUP>−1</SUP>, respectively, which confirmed the fabrication of GO on the GC electrode, and the ratio of the D and G bands was increased after the electrochemical reduction of GO. The surface coverage of the modified electrode was 8.16×10<SUP>−11</SUP> molcm<SUP>−2</SUP>. The p-DAB@ERGO/GC film-modified electrode was used successfully for the determination of nitrite ions. The p-DAB@ERGO/GC film-modified electrode exhibited superior activity for the determination of nitrite compared to the bare GC and p-DAB@GC electrodes. The amperometric current increased linearly with increasing nitrite concentration from 7.0×10<SUP>−6</SUP> to 2.0×10<SUP>−2</SUP> M. The detection limit was 30nM (S/N=3). In addition, the modified electrode was used successfully to determine the nitrite ion concentration in the presence of a 100-fold excess of common interferents. The practical application of the modified electrode was demonstrated by determining the nitrite ion concentration in water samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel diaminobenzene film on ERGO was fabricated by potentiodynamic method. </LI> <LI> p-DAB@ERGO/GC shows excellent activity towards nitrite. </LI> <LI> The proposed sensor exhibits lowest detection limit and wide linear range. </LI> <LI> Modified electrode was successfully applied to the analysis in water samples. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Microwave-assisted binder-free synthesis of 3D Ni-Co-Mn oxide nanoflakes@Ni foam electrode for supercapacitor applications

Lamiel, Charmaine,Nguyen, Van Hoa,Kumar, Deivasigamani Ranjith,Shim, Jae-Jin Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.316 No.-

<P><B>Abstract</B></P> <P>The outstanding performance of nickel foam (NF) as a current collector owing to its better dimensional stability, high electrical conductivity, and less contact resistance has made it a promising candidate for binder-free electrode for supercapacitors. In addition to the current collector, highly stable structures are also favored to facilitate rapid ion insertion and prevent structural collapse of the electrode materials. In this work, a binder-free and controlled structure of Ni-Co-Mn oxide on NF was constructed effectively using microwave irradiation. The structure obtained from the optimal conditions (concentration and holding time) involved hierarchical interconnected nanoflakes with void spaces, forming a stable and conductive network of nanoflakes on the NF. The synergistic effects of three metal (Ni-Co-Mn) oxides resulted in a high specific capacitance of 2536Fg<SUP>−1</SUP> at 5mAcm<SUP>−2</SUP> (6.49Ag<SUP>−1</SUP>) in a mixed KOH/K<SUB>3</SUB>Fe(CN)<SUB>6</SUB> electrolyte. The as-prepared symmetric device also obtained a high capacitance of 298Fg<SUP>−1</SUP>, a high energy density of 41.4Whkg<SUP>−1</SUP>, and a high power density of 5.4kWkg<SUP>−1</SUP>. The highly architectured Ni-Co-Mn oxide nanoflakes improved the pseudocapacitive performance significantly, making it a promising electrode material for high-performance binder-free supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchical 3D Ni-Co-Mn oxide@Ni foam was synthesized within 30s under microwave. </LI> <LI> Max. capacitance was 1151Fg<SUP>−1</SUP> in KOH and increased to 106.5% after 5000 cycles. </LI> <LI> Capacitance was 2356Fg<SUP>−1</SUP> with 79.6% retained after 5000 cycles using K<SUB>3</SUB>Fe(CN)<SUB>6</SUB>. </LI> <LI> Symmetrical supercapacitor was with an ED of 43.8Whkg<SUP>−1</SUP> and PD of 5.8kWkg<SUP>−1</SUP>. </LI> <LI> Energy density of 41.4Whkg<SUP>−1</SUP> and power density of 5.4kWkg<SUP>−1</SUP> for supercapacitor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Solar light-active S-scheme TiO2/In2S3 heterojunction photocatalyst for organic pollutants degradation

Manjiri A. Mahadadalkar,Ganesh Dhakal,Sumanta Sahoo,Deivasigamani Ranjith Kumar,Marjorie Lara Baynosa,Van Quang Nguyen,Mostafa Saad Sayed,Abdelrahman M. Rabie,Woo Kyoung Kim,Jae-Jin Shim 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

Heterojunction TiO2/In2S3 composite photocatalyst was prepared using a simple low-temperature onestephydrothermal method. In2S3 nanosheets with a thickness of 1–5 nm were decorated with 20–30 nm TiO2 nanoparticles, forming a stable heterojunction. The electron transfer mechanism and bandalignment between TiO2 and In2S3 was studied using X-ray photoelectron spectroscopy and UV–visiblespectroscopy, which suggested the formation of an S-scheme heterojunction in TiO2/In2S3 composite. The TiO2/In2S3 composite with a 1:1 mole ratio showed 99.9% photocatalytic degradation ofRhodamine B within 20 minutes of solar light irradiation, which was better than the results for pristineTiO2, pristine In2S3, and their physical mixture, as well as any other previously reported materials of thesame kind. The as-prepared TiO2/In2S3 composite showed excellent stability (98% for Rhodamine B) evenafter five successive reuse cycles. This excellent performance of TiO2/In2S3 was attributed to the S-schemeheterojunction because of an internal electric field, columbic attraction, and band bending. A radical trappingstudy showed that superoxide radicals O2 contribute the most to the photocatalytic degradationof Rhodamine B followed by hydroxyl radicals (OH) and holes (hVB+ ). The use of a low synthesis temperatureand a simple, one-step formation method, with no secondary pollutants generated, makes this processan environmentally friendly and sustainable solution for cost-effective wastewater treatment,highlighting its future commercial applications.