Dephan Pinheiro | Christ University, Bangalore, India (original) (raw)

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Papers by Dephan Pinheiro

Journal of The Electrochemical Society, Mar 1, 2023

In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly ... more In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly improved the design and engineering of high performance electrode materials and have found applications in energy storage devices. This study explores the supercapacitor and electrocatalytic water splitting applications of Mn-MOF/reduced graphene oxide (rGO) composite synthesized via a hydrothermal technique using pyridine 2,6 dicarboxylic acid as a linker. Mn-MOF/rGO exhibits a specific capacitance of 428.28 F g−1 with a rate capability of 83.7% and high cyclic stability. The oxygen evolution reaction of the composite is evaluated using linear sweep voltammetry, and the overpotential is calculated to be 400 mV. Our primary goal is to investigate the effect of rGO on the electrochemical response of MOF. The dielectrode (Mn-MOF/rGO) electrolysis system exhibits long-run stability with a low cell potential of 1.8 V, indicating its prospective application as an excellent water electrolyzer. The combination of Mn-MOF with rGO helps in increasing the number of active sites, thereby improving its electronic conductivity by enhancing the electron transfer rate. The outstanding electrochemical behaviour of Mn-MOF/rGO paves the way for the use of rGO-incorporated Mn-MOF in bifunctional applications as energy-generating and storage devices.

Environmental Science and Pollution Research, May 18, 2021

A new family of polyoxometalates-based inorganiceorganic hybrid compounds, namely, [Ag 4 (H 2 O)(... more A new family of polyoxometalates-based inorganiceorganic hybrid compounds, namely, [Ag 4 (H 2 O)(L) 3 (SiW 12 O 40)] (1), [Zn(L)(H 2 O)] 2 [SiW 12 O 40 ]$3H 2 O (2), [Cu(L)(H 2 O)] 2 [SiW 12 O 40 ] (3), and [Cu 2 (L) 2 (HPW VI 10 W V 2 O 40)]$4H 2 O (4), have been synthesized (L ¼ 1,4ebis(3-(2-pyridyl)pyrazol)butane). This series of inorganiceorganic hybrid compounds exhibit variable supramolecular architectures. The photodegradation of organic dyes malachite green and methylene blue with the use of compounds 1e4 as photocatalysts was studied under visible light irradiation. Strikingly, the photocatalytic result demonstrates that compound 1 is an efficient photocatalyst for the removal of malachite green and methylene blue. Remarkably, compound 1 serves as an active and recyclable photocatalyst for the reduction of Cr VI with isopropanol as scavenger at ambient temperature. The catalytic oxidative desulfurization of thioanisole was also investigated with the use of compounds 1e4 as catalysts and tert-butyl hydroperoxide as oxidant. The catalytic results indicate that compounds 3 and 4 behave high catalytic performance for the oxidation of the thioanisole.

Materials Today Chemistry, Jul 1, 2023

Electrochimica Acta, Sep 1, 2023

International Journal of Hydrogen Energy, Apr 1, 2023

ChemistrySelect, Jul 4, 2023

Materials today communications, Jun 1, 2023

Materials Today Communications

Journal of The Electrochemical Society

In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly ... more In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly improved the design and engineering of high performance electrode materials and have found applications in energy storage devices. This study explores the supercapacitor and electrocatalytic water splitting applications of Mn-MOF/reduced graphene oxide (rGO) composite synthesized via a hydrothermal technique using pyridine 2,6 dicarboxylic acid as a linker. Mn-MOF/rGO exhibits a specific capacitance of 428.28 F g−1 with a rate capability of 83.7% and high cyclic stability. The oxygen evolution reaction of the composite is evaluated using linear sweep voltammetry, and the overpotential is calculated to be 400 mV. Our primary goal is to investigate the effect of rGO on the electrochemical response of MOF. The dielectrode (Mn-MOF/rGO) electrolysis system exhibits long-run stability with a low cell potential of 1.8 V, indicating its prospective application as an excellent water electrolyzer....

International Journal of Hydrogen Energy

Materials Today Communications

Materials Today Chemistry

Russian Journal of Organic Chemistry, 2020

Zirconia supported silica from rice husk (an agricultural waste) has been utilized as a novel and... more Zirconia supported silica from rice husk (an agricultural waste) has been utilized as a novel and efficient heterogeneous catalyst for the synthesis of bioactive tetrahydro-1-benzopyran derivatives via multicomponent condensation of various aldehydes with dimedone and malononitrile. This protocol offers various advantages such as high yields, simple experimental work-up procedure, short reaction time, no by-products, economic availability, easy purification, and reusability of the catalyst.

Asian Journal of Organic Chemistry, 2021

Materials Today: Proceedings, 2020

Glycerol, an inexpensive by-product from biodiesel production can be converted into many useful p... more Glycerol, an inexpensive by-product from biodiesel production can be converted into many useful products notably glycidol, which has a wide range of uses. In this study, glycidol synthesis has been done using a biowaste mediated catalyst in a single step process. Silica and potassium incorporated silica were synthesized from biowaste rice husk. These catalysts were characterized by different spectroscopic techniques. Basic sites in the catalysts were estimated using temperature-programmed desorption study. Four operational parameters were optimized using Box Behnken Design (BBD) of response surface methodology (RSM). Potassium incorporated rice husk was found to be one of the best catalysts for glycidol production with 60.8% glycerol conversion and 62.9% selectivity within one hour of reaction time.

Materials Science in Semiconductor Processing, 2019

A surfactant mediated sol-gel method is employed to synthesize bismuth silicate heterostructures ... more A surfactant mediated sol-gel method is employed to synthesize bismuth silicate heterostructures with tunable morphologies and properties. The synthesized nanoparticle samples were characterized by XRD, FTIR Spectroscopy, SEM-EDAX and UV-DRS. The synthesized bismuth silicates exhibit excellent photodegradation against malachite green and rhodamine B dyes in the aqueous medium. Bismuth silicates (10% SiO 2-Bi 2 O 3) show superior photocatalytic property and outstanding reusability compared to pure bismuth oxide. The kinetics of the photodegradation of the dyes shows that the reaction follows first-order kinetics with the regression coefficient of 0.99. Thus, enabling Bismuth silicates heterostructures practical application as a photocatalyst for clean water.

Australian Journal of Chemistry, 2019

Bismuth oxide with its unique narrow bandgap has gained significant attention in the field of pho... more Bismuth oxide with its unique narrow bandgap has gained significant attention in the field of photocatalysis. A new and efficient method to synthesise bismuth oxide with tuneable properties is proposed herein. A surfactant assisted modified sol–gel method is used to synthesise bismuth oxide with excellent photocatalytic activity for the degradation of Rhodamine B dye. Three different surfactants, namely polyethylene glycol-400, sodium lauryl sulfate, and cetyltrimethylammonium bromide (CTAB) have been used. The fabricated bismuth oxide nanoparticles were characterised by X-ray diffraction, IR, scanning electron microscopy, and UV-diffuse reflectance spectroscopy analysis. Evolution of both the α and β crystalline phases of bismuth oxide was observed. The bandgap of the synthesised bismuth oxides ranges from 2.03 to 2.37eV. The CTAB assisted synthesised bismuth oxide with a bandgap of 2.19eV showed the highest photocatalytic activity of 93.6% under visible light for the degradation o...

Journal of The Electrochemical Society, Mar 1, 2023

In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly ... more In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly improved the design and engineering of high performance electrode materials and have found applications in energy storage devices. This study explores the supercapacitor and electrocatalytic water splitting applications of Mn-MOF/reduced graphene oxide (rGO) composite synthesized via a hydrothermal technique using pyridine 2,6 dicarboxylic acid as a linker. Mn-MOF/rGO exhibits a specific capacitance of 428.28 F g−1 with a rate capability of 83.7% and high cyclic stability. The oxygen evolution reaction of the composite is evaluated using linear sweep voltammetry, and the overpotential is calculated to be 400 mV. Our primary goal is to investigate the effect of rGO on the electrochemical response of MOF. The dielectrode (Mn-MOF/rGO) electrolysis system exhibits long-run stability with a low cell potential of 1.8 V, indicating its prospective application as an excellent water electrolyzer. The combination of Mn-MOF with rGO helps in increasing the number of active sites, thereby improving its electronic conductivity by enhancing the electron transfer rate. The outstanding electrochemical behaviour of Mn-MOF/rGO paves the way for the use of rGO-incorporated Mn-MOF in bifunctional applications as energy-generating and storage devices.

Environmental Science and Pollution Research, May 18, 2021

A new family of polyoxometalates-based inorganiceorganic hybrid compounds, namely, [Ag 4 (H 2 O)(... more A new family of polyoxometalates-based inorganiceorganic hybrid compounds, namely, [Ag 4 (H 2 O)(L) 3 (SiW 12 O 40)] (1), [Zn(L)(H 2 O)] 2 [SiW 12 O 40 ]$3H 2 O (2), [Cu(L)(H 2 O)] 2 [SiW 12 O 40 ] (3), and [Cu 2 (L) 2 (HPW VI 10 W V 2 O 40)]$4H 2 O (4), have been synthesized (L ¼ 1,4ebis(3-(2-pyridyl)pyrazol)butane). This series of inorganiceorganic hybrid compounds exhibit variable supramolecular architectures. The photodegradation of organic dyes malachite green and methylene blue with the use of compounds 1e4 as photocatalysts was studied under visible light irradiation. Strikingly, the photocatalytic result demonstrates that compound 1 is an efficient photocatalyst for the removal of malachite green and methylene blue. Remarkably, compound 1 serves as an active and recyclable photocatalyst for the reduction of Cr VI with isopropanol as scavenger at ambient temperature. The catalytic oxidative desulfurization of thioanisole was also investigated with the use of compounds 1e4 as catalysts and tert-butyl hydroperoxide as oxidant. The catalytic results indicate that compounds 3 and 4 behave high catalytic performance for the oxidation of the thioanisole.

Materials Today Chemistry, Jul 1, 2023

Electrochimica Acta, Sep 1, 2023

International Journal of Hydrogen Energy, Apr 1, 2023

ChemistrySelect, Jul 4, 2023

Materials today communications, Jun 1, 2023

Materials Today Communications

Journal of The Electrochemical Society

In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly ... more In recent years, metal organic frameworks (MOFs) with porous carbon materials have significantly improved the design and engineering of high performance electrode materials and have found applications in energy storage devices. This study explores the supercapacitor and electrocatalytic water splitting applications of Mn-MOF/reduced graphene oxide (rGO) composite synthesized via a hydrothermal technique using pyridine 2,6 dicarboxylic acid as a linker. Mn-MOF/rGO exhibits a specific capacitance of 428.28 F g−1 with a rate capability of 83.7% and high cyclic stability. The oxygen evolution reaction of the composite is evaluated using linear sweep voltammetry, and the overpotential is calculated to be 400 mV. Our primary goal is to investigate the effect of rGO on the electrochemical response of MOF. The dielectrode (Mn-MOF/rGO) electrolysis system exhibits long-run stability with a low cell potential of 1.8 V, indicating its prospective application as an excellent water electrolyzer....

International Journal of Hydrogen Energy

Materials Today Communications

Materials Today Chemistry

Russian Journal of Organic Chemistry, 2020

Zirconia supported silica from rice husk (an agricultural waste) has been utilized as a novel and... more Zirconia supported silica from rice husk (an agricultural waste) has been utilized as a novel and efficient heterogeneous catalyst for the synthesis of bioactive tetrahydro-1-benzopyran derivatives via multicomponent condensation of various aldehydes with dimedone and malononitrile. This protocol offers various advantages such as high yields, simple experimental work-up procedure, short reaction time, no by-products, economic availability, easy purification, and reusability of the catalyst.

Asian Journal of Organic Chemistry, 2021

Materials Today: Proceedings, 2020

Glycerol, an inexpensive by-product from biodiesel production can be converted into many useful p... more Glycerol, an inexpensive by-product from biodiesel production can be converted into many useful products notably glycidol, which has a wide range of uses. In this study, glycidol synthesis has been done using a biowaste mediated catalyst in a single step process. Silica and potassium incorporated silica were synthesized from biowaste rice husk. These catalysts were characterized by different spectroscopic techniques. Basic sites in the catalysts were estimated using temperature-programmed desorption study. Four operational parameters were optimized using Box Behnken Design (BBD) of response surface methodology (RSM). Potassium incorporated rice husk was found to be one of the best catalysts for glycidol production with 60.8% glycerol conversion and 62.9% selectivity within one hour of reaction time.

Materials Science in Semiconductor Processing, 2019

A surfactant mediated sol-gel method is employed to synthesize bismuth silicate heterostructures ... more A surfactant mediated sol-gel method is employed to synthesize bismuth silicate heterostructures with tunable morphologies and properties. The synthesized nanoparticle samples were characterized by XRD, FTIR Spectroscopy, SEM-EDAX and UV-DRS. The synthesized bismuth silicates exhibit excellent photodegradation against malachite green and rhodamine B dyes in the aqueous medium. Bismuth silicates (10% SiO 2-Bi 2 O 3) show superior photocatalytic property and outstanding reusability compared to pure bismuth oxide. The kinetics of the photodegradation of the dyes shows that the reaction follows first-order kinetics with the regression coefficient of 0.99. Thus, enabling Bismuth silicates heterostructures practical application as a photocatalyst for clean water.

Australian Journal of Chemistry, 2019

Bismuth oxide with its unique narrow bandgap has gained significant attention in the field of pho... more Bismuth oxide with its unique narrow bandgap has gained significant attention in the field of photocatalysis. A new and efficient method to synthesise bismuth oxide with tuneable properties is proposed herein. A surfactant assisted modified sol–gel method is used to synthesise bismuth oxide with excellent photocatalytic activity for the degradation of Rhodamine B dye. Three different surfactants, namely polyethylene glycol-400, sodium lauryl sulfate, and cetyltrimethylammonium bromide (CTAB) have been used. The fabricated bismuth oxide nanoparticles were characterised by X-ray diffraction, IR, scanning electron microscopy, and UV-diffuse reflectance spectroscopy analysis. Evolution of both the α and β crystalline phases of bismuth oxide was observed. The bandgap of the synthesised bismuth oxides ranges from 2.03 to 2.37eV. The CTAB assisted synthesised bismuth oxide with a bandgap of 2.19eV showed the highest photocatalytic activity of 93.6% under visible light for the degradation o...