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Samantha Macchi
Department of Chemistry, University of Arkansas at Little Rock, Little Rock, AR 72204, USA

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Journal article
Published: 30 August 2021 in Sustainable Chemistry
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Herein, an inexpensive commercially available sensor is presented for the detection of 4-nitrophenol (4NP) pollutant. Sodium fluorescein (NaFl) is used as a sensor to detect trace amounts of 4NP in acetonitrile (MeCN). The photophysical properties of NaFl were studied in two different solvents, MeCN (aprotic) and water (protic), with varying concentrations of different nitroaromatics using UV-visible absorption and fluorescence spectrophotometry. In an aqueous medium, photophysical properties of NaFl did not change in the presence of nitroaromatics. However, examination of the photodynamics in MeCN demonstrated that NaFl is extremely sensitive to 4NP (limit of detection: 0.29 µg/mL). This extreme specificity of NaFl towards 4NP when dissolved in MeCN, as compared to other nitroaromatics, is attributed to hydrogen bonding of 4NP with NaFl in the absence of water, resulting in both static and dynamic quenching processes. Thus, NaFl is demonstrated as a simple, inexpensive, sensitive, and robust optical turn off sensor for 4NP.

ACS Style

Thuy Le; Yusuf Khan; Nicholas Speller; Mujeebat Bashiru; Samantha Macchi; Isiah Warner; Noureen Siraj. A Highly Selective Economical Sensor for 4-Nitrophenol. Sustainable Chemistry 2021, 2, 506 -520.

AMA Style

Thuy Le, Yusuf Khan, Nicholas Speller, Mujeebat Bashiru, Samantha Macchi, Isiah Warner, Noureen Siraj. A Highly Selective Economical Sensor for 4-Nitrophenol. Sustainable Chemistry. 2021; 2 (3):506-520.

Chicago/Turabian Style

Thuy Le; Yusuf Khan; Nicholas Speller; Mujeebat Bashiru; Samantha Macchi; Isiah Warner; Noureen Siraj. 2021. "A Highly Selective Economical Sensor for 4-Nitrophenol." Sustainable Chemistry 2, no. 3: 506-520.

Journal article
Published: 02 June 2021 in Electrochem
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There is a growing need to develop sustainable electrocatalysts to facilitate the reduction of molecular oxygen that occurs at the cathode in fuel cells, due to the excessive cost and limited availability of precious metal-based catalysts. This study reports the synthesis and characterization of phosphorus and nitrogen co-doped carbon (PNDC) and silicon, phosphorus, and nitrogen tri-doped carbon (SiPNDC) electrocatalysts derived from molasses. This robust microwave-assisted synthesis approach is used to develop a low cost and environmentally friendly carbon with high surface area for application in fuel cells. Co-doped PNDC as well as tri-doped SiPNDC showed Brunauer–Emmet–Teller (BET) surface areas of 437 and 426 m2 g−1, respectively, with well-developed porosity. However, examination of X-ray photoelectron spectroscopy (XPS) data revealed significant alteration in the doping elemental composition among both samples. The results obtained using rotating disk electrode (RDE) measurements show that tri-doped SiPNDC achieves much closer to a 4-electron process than co-doped PNDC. Detailed analysis of experimental results acquired from rotating ring disk electrode (RRDE) studies indicates that there is a negligible amount of peroxide formation during ORR, further confirming the direct-electron transfer pathway results obtained from RDE. Furthermore, SiPNDC shows stable oxygen reduction reaction (ORR) performance over 2500 cycles, making this material a promising electrocatalyst for fuel cell applications.

ACS Style

Samantha Macchi; Fumiya Watanabe; Tito Viswanathan; Noureen Siraj. Characterization and Electrocatalytic Performance of Molasses Derived Co-Doped (P, N) and Tri-Doped (Si, P, N) Carbon for the ORR. Electrochem 2021, 2, 311 -322.

AMA Style

Samantha Macchi, Fumiya Watanabe, Tito Viswanathan, Noureen Siraj. Characterization and Electrocatalytic Performance of Molasses Derived Co-Doped (P, N) and Tri-Doped (Si, P, N) Carbon for the ORR. Electrochem. 2021; 2 (2):311-322.

Chicago/Turabian Style

Samantha Macchi; Fumiya Watanabe; Tito Viswanathan; Noureen Siraj. 2021. "Characterization and Electrocatalytic Performance of Molasses Derived Co-Doped (P, N) and Tri-Doped (Si, P, N) Carbon for the ORR." Electrochem 2, no. 2: 311-322.

Preprint content
Published: 14 May 2021
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Global access to sanitary water is of utmost importance to human health. Presently, textile dye water pollution and cigarette pollution are both plaguing the environment. Herein, waste cigarette filters are converted into useful carbon-based adsorbent materials via a facile, microwave-assisted carbonization procedure. The cigarette filters are co-doped with phosphorus and nitrogen using ammonium polyphosphate to enhance their surface characteristics and adsorbent capability. The adsorbents are characterized physically to examine their surface area, elemental composition, and surface charge properties. Batch adsorption experiments were performed to determine the maximum adsorption capacity of the adsorbents. Additionally, the effects of various adsorption parameters— temperature, adsorbent dosage, pH, and time—on adsorption process were examined. The doped adsorbent showed a maximum adsorption capacity of 303.3 mg g− 1 respectively, which is three times that of the methylene blue adsorption capacity of commercially available activated carbon (~ 100 mg g− 1). Thus, the phosphorus and nitrogen co-doped carbonized waste cigarette filter adsorbent shows a profound potential as a sustainable solution to combat textile dye water pollution and cigarette filter pollution simultaneously, due to its low cost, simple preparation, and versatility in application.

ACS Style

Samantha Macchi; Zane Alsebai; Fumiya Watanabe; Arooba Ilyas; Shiraz Atif; Tito Viswanathan; Noureen Siraj. Phosphorus and nitrogen co-doped carbon derived from Cigarette Filter for adsorption of methylene blue dye from aqueous solution. 2021, 1 .

AMA Style

Samantha Macchi, Zane Alsebai, Fumiya Watanabe, Arooba Ilyas, Shiraz Atif, Tito Viswanathan, Noureen Siraj. Phosphorus and nitrogen co-doped carbon derived from Cigarette Filter for adsorption of methylene blue dye from aqueous solution. . 2021; ():1.

Chicago/Turabian Style

Samantha Macchi; Zane Alsebai; Fumiya Watanabe; Arooba Ilyas; Shiraz Atif; Tito Viswanathan; Noureen Siraj. 2021. "Phosphorus and nitrogen co-doped carbon derived from Cigarette Filter for adsorption of methylene blue dye from aqueous solution." , no. : 1.

Journal article
Published: 21 January 2021 in Electrochem
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In this study, we have evaluated the effect of potassium hydroxide (KOH) on the energy storage performance of metal-free carbon-based materials prepared from molasses. Molasses are a renewable-resource biomass and economical by-product of sugar refinement, used here as a carbon precursor. Two co-doped carbon materials using molasses were synthesized via a time and cost-efficient microwave carbonization process, with ammonium polyphosphate as a phosphorus and nitrogen doping agent. The phosphorus and nitrogen co-doped carbon (PNDC) samples were prepared in the presence and absence of a chemical activating agent (KOH), to study the role of chemical activation on PNDCs. Physical characterizations were performed to gain insight into the composition, pore size and topographical data of each material. Electrochemical characterization via cyclic voltammetry in 1 M sulfuric acid (H2SO4) as well as in 6 M KOH as electrolytes, revealed high current density and specific capacitance for the chemically activated material (PNDC2) compared to one without chemical activation (PNDC1). The capacitance value of 244 F/g in KOH electrolyte was obtained with PNDC2. It is concluded that addition of KOH prior to carbonization increases the surface functionality, which significantly enhances the electrochemical properties of the PNDC material such as current density, stability, and specific capacitance.

ACS Style

Iris Denmark; Samantha Macchi; Fumiya Watanabe; Tito Viswanathan; Noureen Siraj. Effect of KOH on the Energy Storage Performance of Molasses-Based Phosphorus and Nitrogen Co-Doped Carbon. Electrochem 2021, 2, 29 -40.

AMA Style

Iris Denmark, Samantha Macchi, Fumiya Watanabe, Tito Viswanathan, Noureen Siraj. Effect of KOH on the Energy Storage Performance of Molasses-Based Phosphorus and Nitrogen Co-Doped Carbon. Electrochem. 2021; 2 (1):29-40.

Chicago/Turabian Style

Iris Denmark; Samantha Macchi; Fumiya Watanabe; Tito Viswanathan; Noureen Siraj. 2021. "Effect of KOH on the Energy Storage Performance of Molasses-Based Phosphorus and Nitrogen Co-Doped Carbon." Electrochem 2, no. 1: 29-40.

Review
Published: 07 December 2020 in Sensors
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Quality checks, assessments, and the assurance of food products, raw materials, and food ingredients is critically important to ensure the safeguard of foods of high quality for safety and public health. Nevertheless, quality checks, assessments, and the assurance of food products along distribution and supply chains is impacted by various challenges. For instance, the development of portable, sensitive, low-cost, and robust instrumentation that is capable of real-time, accurate, and sensitive analysis, quality checks, assessments, and the assurance of food products in the field and/or in the production line in a food manufacturing industry is a major technological and analytical challenge. Other significant challenges include analytical method development, method validation strategies, and the non-availability of reference materials and/or standards for emerging food contaminants. The simplicity, portability, non-invasive, non-destructive properties, and low-cost of NIR spectrometers, make them appealing and desirable instruments of choice for rapid quality checks, assessments and assurances of food products, raw materials, and ingredients. This review article surveys literature and examines current challenges and breakthroughs in quality checks and the assessment of a variety of food products, raw materials, and ingredients. Specifically, recent technological innovations and notable advances in quartz crystal microbalances (QCM), electroanalytical techniques, and near infrared (NIR) spectroscopic instrument development in the quality assessment of selected food products, and the analysis of food raw materials and ingredients for foodborne pathogen detection between January 2019 and July 2020 are highlighted. In addition, chemometric approaches and multivariate analyses of spectral data for NIR instrumental calibration and sample analyses for quality assessments and assurances of selected food products and electrochemical methods for foodborne pathogen detection are discussed. Moreover, this review provides insight into the future trajectory of innovative technological developments in QCM, electroanalytical techniques, NIR spectroscopy, and multivariate analyses relating to general applications for the quality assessment of food products.

ACS Style

David K. Bwambok; Noureen Siraj; Samantha Macchi; Nathaniel E. Larm; Gary A. Baker; Rocío L. Pérez; Caitlan E. Ayala; Charuksha Walgama; David Pollard; Jason D. Rodriguez; Souvik Banerjee; Brianda Elzey; Isiah M. Warner; Sayo O. Fakayode. QCM Sensor Arrays, Electroanalytical Techniques and NIR Spectroscopy Coupled to Multivariate Analysis for Quality Assessment of Food Products, Raw Materials, Ingredients and Foodborne Pathogen Detection: Challenges and Breakthroughs. Sensors 2020, 20, 6982 .

AMA Style

David K. Bwambok, Noureen Siraj, Samantha Macchi, Nathaniel E. Larm, Gary A. Baker, Rocío L. Pérez, Caitlan E. Ayala, Charuksha Walgama, David Pollard, Jason D. Rodriguez, Souvik Banerjee, Brianda Elzey, Isiah M. Warner, Sayo O. Fakayode. QCM Sensor Arrays, Electroanalytical Techniques and NIR Spectroscopy Coupled to Multivariate Analysis for Quality Assessment of Food Products, Raw Materials, Ingredients and Foodborne Pathogen Detection: Challenges and Breakthroughs. Sensors. 2020; 20 (23):6982.

Chicago/Turabian Style

David K. Bwambok; Noureen Siraj; Samantha Macchi; Nathaniel E. Larm; Gary A. Baker; Rocío L. Pérez; Caitlan E. Ayala; Charuksha Walgama; David Pollard; Jason D. Rodriguez; Souvik Banerjee; Brianda Elzey; Isiah M. Warner; Sayo O. Fakayode. 2020. "QCM Sensor Arrays, Electroanalytical Techniques and NIR Spectroscopy Coupled to Multivariate Analysis for Quality Assessment of Food Products, Raw Materials, Ingredients and Foodborne Pathogen Detection: Challenges and Breakthroughs." Sensors 20, no. 23: 6982.

Review
Published: 13 November 2020 in Electrochem
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Herein, metal-free heteroatom doped carbon-based materials are being reviewed for supercapacitor and energy applications. Most of these low-cost materials considered are also derived from renewable resources. Various forms of carbon that have been employed for supercapacitor applications are described in detail, and advantages as well as disadvantages of each form are presented. Different methodologies that are being used to develop these materials are also discussed. To increase the specific capacitance, carbon-based materials are often doped with different elements. The role of doping elements on the performance of supercapacitors has been critically reviewed. It has been demonstrated that a higher content of doping elements significantly improves the supercapacitor behavior of carbon compounds. In order to attain a high percentage of elemental doping, precursors with variable ratios as well as simple modifications in the syntheses scheme have been employed. Significance of carbon-based materials doped with one and more than one heteroatom have also been presented. In addition to doping elements, other factors which play a key role in enhancing the specific capacitance values such as surface area, morphology, pore size electrolyte, and presence of functional groups on the surface of carbon-based supercapacitor materials have also been summarized.

ACS Style

Noureen Siraj; Samantha Macchi; Brian Berry; Tito Viswanathan. Metal-Free Carbon-Based Supercapacitors—A Comprehensive Review. Electrochem 2020, 1, 410 -438.

AMA Style

Noureen Siraj, Samantha Macchi, Brian Berry, Tito Viswanathan. Metal-Free Carbon-Based Supercapacitors—A Comprehensive Review. Electrochem. 2020; 1 (4):410-438.

Chicago/Turabian Style

Noureen Siraj; Samantha Macchi; Brian Berry; Tito Viswanathan. 2020. "Metal-Free Carbon-Based Supercapacitors—A Comprehensive Review." Electrochem 1, no. 4: 410-438.

Journal article
Published: 01 April 2020 in Environmental Technology
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Herein, a facile synthesis of heteroatom doped biochar is reported. The material is characterized and analyzed in detail for its application as a low-cost adsorbent for removal of a toxic dye pollutant, Methylene Blue (MB), from aqueous solution. Synthesized material showed enhanced surface area compared to parent biochar (458 to802 m2g-1) The adsorbent's performance is investigated using batch adsorption methods with experiments conducted at varying conditions of adsorbent dosage, initial dye concentration (50-500 mg/L), and pH (3-11). Adsorption of MB onto two different adsorbents such as biochar (BC) and doped BC, is fitted using Langmuir and Freundlich isotherms with the experimental data correlating most accurately with Langmuir modelling, indicating chemisorption mechanism of dye onto adsorbent. Maximum monolayer equilibrium adsorption from Langmuir equation is found to be 129.8 and 357.1 mg/g for pure BC and Phosphorus and Nitrogen co-doped BC (PNBC), respectively. Pseudo-first and -second order kinetic models are applied to investigate the adsorption mechanism of PNBC. Adsorption mechanism followed pseudo-second order model well, with correlation coefficients very close to 1. The results indicate that microwave-assisted heteroatom co-doped BC showed superior performance as adsorbent for the adsorption of MB dye from aqueous solution.

ACS Style

Samantha Macchi; Noureen Siraj; Tito Viswanathan. Kinetic and mechanistic study of dye sorption onto renewable resource-based doped carbon prepared by a microwave-assisted method. Environmental Technology 2020, 1 -10.

AMA Style

Samantha Macchi, Noureen Siraj, Tito Viswanathan. Kinetic and mechanistic study of dye sorption onto renewable resource-based doped carbon prepared by a microwave-assisted method. Environmental Technology. 2020; ():1-10.

Chicago/Turabian Style

Samantha Macchi; Noureen Siraj; Tito Viswanathan. 2020. "Kinetic and mechanistic study of dye sorption onto renewable resource-based doped carbon prepared by a microwave-assisted method." Environmental Technology , no. : 1-10.

Journal article
Published: 02 July 2019 in Applied Spectroscopy Reviews
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ACS Style

Sayo O. Fakayode; Gary A. Baker; David K. Bwambok; Nakara Bhawawet; Brianda Elzey; Noureen Siraj; Samantha Macchi; David A. Pollard; Rocio L. Perez; A'ja V. Duncan; Isiah M. Warner. Molecular (Raman, NIR, and FTIR) spectroscopy and multivariate analysis in consumable products analysis1. Applied Spectroscopy Reviews 2019, 55, 647 -723.

AMA Style

Sayo O. Fakayode, Gary A. Baker, David K. Bwambok, Nakara Bhawawet, Brianda Elzey, Noureen Siraj, Samantha Macchi, David A. Pollard, Rocio L. Perez, A'ja V. Duncan, Isiah M. Warner. Molecular (Raman, NIR, and FTIR) spectroscopy and multivariate analysis in consumable products analysis1. Applied Spectroscopy Reviews. 2019; 55 (8):647-723.

Chicago/Turabian Style

Sayo O. Fakayode; Gary A. Baker; David K. Bwambok; Nakara Bhawawet; Brianda Elzey; Noureen Siraj; Samantha Macchi; David A. Pollard; Rocio L. Perez; A'ja V. Duncan; Isiah M. Warner. 2019. "Molecular (Raman, NIR, and FTIR) spectroscopy and multivariate analysis in consumable products analysis1." Applied Spectroscopy Reviews 55, no. 8: 647-723.

Full paper
Published: 11 January 2019 in ChemistrySelect
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Herein, renewable resource‐based waste materials (used tea leaves and molasses) were utilized as inexpensive and renewable carbon sources to develop Phosphorus and Nitrogen co‐doped Carbon (PNDC) materials for supercapacitor application. A prompt, low cost, single step, green and facile microwave assisted process was utilized to prepare PNDC materials using the aforementioned biomass. Concentration of the doping elements (P and N) was altered in the resulting PNDC materials by varying the mole ratio of used tea/molasses and ammonium polyphosphate (APP) in the reaction mixture. APP served as the Phosphorus and Nitrogen source as well as the microwave absorber. Detailed characterization of all four PNDCs ‐ two derived from molasses (MOLPNDCs) and two from used tea leaves (TEAPNDCs), were performed to investigate their supercapacitor performance. These materials were characterized both physically via BET, XPS, and SEM analysis and electrochemically via cyclic voltammetry, in both 1 M H2SO4 and 6 M KOH. Pore size, surface area, and elemental compositions of each PNDC was analyzed to investigate the critical parameter for supercapacitor performance of the materials. Among all PNDCs, MOLPNDC‐1 exhibited exceptionally high specific capacitance values of 160 Fg−1 in 6 M KOH electrolyte due to highly mesoporous structure and appropriate Nitrogen content. MOLPNDC‐1 was also found to be stable under continuous cycling for 1500 cycles in both acidic and alkaline conditions.

ACS Style

Samantha Macchi; Noureen Siraj; Fumiya Watanabe; Tito Viswanathan. Renewable‐Resource‐Based Waste Materials for Supercapacitor Application. ChemistrySelect 2019, 4, 492 -501.

AMA Style

Samantha Macchi, Noureen Siraj, Fumiya Watanabe, Tito Viswanathan. Renewable‐Resource‐Based Waste Materials for Supercapacitor Application. ChemistrySelect. 2019; 4 (2):492-501.

Chicago/Turabian Style

Samantha Macchi; Noureen Siraj; Fumiya Watanabe; Tito Viswanathan. 2019. "Renewable‐Resource‐Based Waste Materials for Supercapacitor Application." ChemistrySelect 4, no. 2: 492-501.