Sex: Male

  • Doctor of Philosophy in Chemistry, De La Salle University, 2021
  • Master of Science in Chemistry, De La Salle University, 2014
  • Bachelor of Science in Chemistry for Teachers, Philippine Normal University, 2009

Field of Specialization:
Nanomaterials and nanocomputers
Dye-Sensitized Solar Cell


Article title: Influence of pre-cursor chemistry in the property of carbon nanodots and its application for degradation of methyl orange.
Authors: Jessa C. Leuterio, Drexel H. Camacho, Jose Paolo O. Bantang, Cristian Ryan A. Argamino
Publication title: Materials Chemistry and Physics, 278 (15), 125668, 2022

Carbon nanodots (CNDs) are interesting materials from renewable sources that exhibit unique fluorescence property. This study reports that sulfated carrageenan (ᴋ-, ɩ-, λ-) as carbon precursors for CNDs impart unique properties not observed in a non-sulfated source. Hydrothermal process afforded CNDs having quasi-spherical shapes (TEM), nano sizes (TEM: 3.8 nm; DLS 1.0–2.3 nm), luminous green property under UV light, and presence of sulfur in CNDs (EDS, FTIR). The CNDs were embedded in a carrageenan film matrix to prevent its aggregation and to improve its stability affording brown-colored free-standing films that have better stability (zeta potential) compared to bare CNDs in solution. The CNDs from carrageenan exhibited unique acidic property in water, which is not observed in CNDs from galactose indicating that the sulfate-laden carrageenan precursor imparts unique property to the CNDs. Degradation activity on methyl orange (MO) dye was only observed for CNDs derived from carrageenan and not from galactose confirming the critical role of precursor chemistry in imparting unique acidic properties to the resulting CNDs. The study demonstrated the difference in the carrageenan-based CNDs compared to those prepared from simple sugar and showed its application for the degradation of dyes without the need for direct exposure to sunlight.
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Article title: Gel and Film Composites of Silver Nanoparticles in κ-, ι-, and λ-Carrageenans: One-Pot Synthesis, Characterization, and Bioactivities.
Authors: Jose Paolo O. Bantang &Ursela G. Bigol &Drexel H. Camacho
Publication title: BioNanoScience 11(1): 53-66, 2021

Gel and film composites containing silver nanoparticles (AgNPs) were biosynthesized using carrageenan as the reducing agent, capping biomolecule, and polymer matrix in one-pot method. A comparison between the in situ syntheses of AgNPs was made between κ-, ι-, and λ-carrageenans. The structure and morphology of AgNPs in the composite were investigated using UV-visible and infrared spectroscopies, scanning and transmission electron microscopies, and thermal gravimetric analysis. The antimicrobial properties were also evaluated. Results showed that AgNPs fabrication was influenced by the carrageenan type, incubation temperature, and carrageenan concentration. High incubation temperature promoted the reduction of AgNPs. κ-Carrageenan showed stronger reduction capabilities of Ag⁺ than the other carrageenan types. Gel and film formabilities were also observed to be superior in κ-carrageenan than in the ι-, and λ- types. Higher concentrations (1%) of carrageenans promoted more Ag⁺ reduction and less aggregation of AgNPs. The formation of AgNPs was found to be independent of initial Ag⁺ concentration and that excess Ag⁺ ions are still present in the solution allowing for the formation of stable gel and free-standing film for κ-carrageenan compared with the ι-, and λ-carrageenans incorporating the AgNPs in the composite matrix. Microbial activities show that solutions of carrageenan/AgNP/Ag⁺ are active against bacteria and fungi. Gel and film forms of κ-carrageenan/AgNP/Ag⁺ are also active against bacteria.
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Article title: Green production of potassium sulfate by hydrothermal carbonization of carrageenan.
Authors: Jose Paolo O. Bantang and Drexel H. Camacho
Publication title: Asian Journal of Chemistry 32(12):3105-3108, 2020

A novel green method of producing potassium sulfate from a sustainable source is described. Aqueous carrageenan is subjected to hydrothermal carbonization inside a pressure vessel. Separation of the liquid component from the hydrochar followed by evaporation to dryness and treatment with ethanol afforded potassium sulfate. Characterization using SEM-EDX, XRD and Raman spectroscopy confirms the identity of potassium sulfate in the form of K3H(SO4)2. The green process allows the facile release of sulfate ester group from the carrageenan chains and combining with the residual potassium ions in the carrageenan. The new method allows for the simplification of the process of producing potassium sulfate in an environmental friendly way and using a renewable source.
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Article title: Carrageenan-stabilized silver nanoparticle gel probe kit for colorimetric sensing of mercury (II) using digital image analysis.
Authors: Michaela Olisha S. Lobregas, Jose Paolo O. Bantang, Drexel H. Camacho
Publication title: Sensing and Bio-Sensing Research, 26(August): 100303, 2019

Hydrophilic gelling kit consisting of carrageenan-stabilized silver nanoparticles (AgNPs) is described herein as a selective probe for the colorimetric detection of Hg2+. Spherical AgNPs with surface plasmon resonance (SPR) at 430 nm and TEM size of less than 100 nm were synthesized using κ-carrageenan to give a dark brown gelling mixture (Carr-AgNP) that were used directly for colorimetric reaction with various metal ions. The reaction is selective only to Hg2+. The dark brown color of the Carr-AgNP was found to fade as the concentration of Hg2+ increases until the mixture turns white. It can detect Hg2+ at a concentration of ≥350 ppm with limits of detection at 2.92 × 10−4 M. Quantification of the color change was established using digital photometry with strong correlation observed for L*, R and G color parameters. The role of chlorides in the colorimetric sensing is critical to detecting Hg2+ as excess chlorides promote the formation of AgCl as well as the dissolution of AgNP. The utility of the gelling kit was successfully applied for the detection of mercury(II) in a cosmetic cream sample.
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Article title: Adenosine Triphosphate Templated Self-Assembly of Cationic Porphyrin into Chiral Double Superhelices and Enzyme-Mediated Disassembly.
Authors: Zhiliang Li, Charles J. Zeman IV, Silvano R. Valandro, Jose Paolo O. Bantang, and Kirk S. Schanze
Publication title: Journal of the American Chemical Society 141(32), 2019

Self-assembly of small molecules through non-covalent interactions into nanoscale architectures has been extensively studied in supramolecular chemistry. However, it is still challenging to develop a biologically inspired self-assembly system that functions in water with complex structure and dynamics nature by analogy with those found in nature. Here, we report a new water-soluble cationic porphyrin which undergoes adenosine triphosphate (ATP) templated self-assembly into right-handed double-helical supramolecular structures. Direct observation of the porphyrin-ATP assembly by transmission electron microscopy has been accomplished. The assemblies consist of superhelical fibers with length greater than 1 m and width ~ 20 nm. The chiral superhelical fibers show reversible disassembly to monomers upon hydrolysis of ATP when catalyzed by alkaline phosphatase (ALP), and the nanofibers can be reformed with subsequent addition of ATP. Moreover, a transient self-assembly of a chiral double helix is formed when ALP is present to consume ATP.
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Article title: Photocathode Chromophore-Catalyst Assembly via Layer-By-Layer Deposition of a Low Band-Gap Isoindigo Conjugated Polyelectrolyte.
Authors: Gyu Leem, Hayden T. Black, Bing Shan, Jose P. O. Bantang, Thomas J. Meyer, John R. Reynolds, and Kirk S. Schanze
Publication title: ACS Applied Energy Materials 1(1):62-67, 2018

Low band-gap conjugated polyelectrolytes (CPEs) can serve as efficient chromophores for use on photoelectrodes for dye-sensitized photoelectrochemical cells. Herein is report-ed a novel CPE based on poly(isoindigo-co-thiophene) with pendant sodium butylsulfonate groups (PiIT) and its use in construction of layer-by-layer (LbL) chromophore-catalyst assemblies with a Pt-based H+ reduction catalyst (PAA-Pt) for water reduction. A novel Stille polymerization/ post-polymerization ion-exchange strategy was used to convert an organic soluble CPE to the water-soluble poly(isoindigo-co-thiophene). The anionic PiIT polyelectrolyte and poly-acrylate stabilized Pt-nanoparticles (PAA-Pt) were co-deposited with cationic poly(diallyldimethylammonium) chloride (PDDA) onto inverse opal (IO), nanostructured indium tin oxide film (nITO) (IO nITO) atop fluorine doped tin oxide (FTO) by using LbL self-assembly. To evaluate the performance of novel conjugated PiIT//PAA-Pt chromphore-catalyst assemblies, inter-assembly hole trans-fer was investigated by photocurrent density measurements on FTO//IO nITO electrodes. Enhanced cathodic photocur-rent is observed for the polychromophore-catalyst assem-blies, compared to electrodes modified with only PiIT, point-ing towards photoinduced hole transfer from the excited PilT to the IO ITO. Prolonged photoelectrolysis experiments reveal H2 production with a Faradaic yield of approximately 45%. This work provides new routes to carry out visible-light-driven water reduction using photocathode assemblies based on low band-gap CPEs.
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Article title: Gelling polysaccharide as the electrolyte matrix in a dye-sensitized solar cell.
Authors: Jose Paolo Bantang and Drexel Camacho
Publication title: Materials and Technologies 51(5):823-829, October 2017

Hydrophilic polysaccharide, κ-carrageenan, was utilized as the polymer matrix in gel-electrolyte systems for dye-sensitized solar-cell (DSSC) applications. The influence of the solvent system was investigated to optimize the solubility of κ-carrageenan and tetrabutylammonium-iodide (TBAI)/I2 electrolytes by minimizing the water content because of its unfavorable effect on DSSCs. We report herein that two solvent systems, a water/acetonitrile mixed solvent and DMSO, were found to effectively dissolve the components. The composite natures of the κ-carrageenan-electrolyte systems in these solvents were confirmed with an FTIR analysis. The presence of κ-carrageenan did not impede the electrochemical properties of the electrolytes, as confirmed with cyclic voltammetry, electrochemical impedance spectroscopy and linear sweep voltammetry. The incorporation of the gel electrolytes in DSSCs showed that the DMSO system exhibited better solar-cell efficiency compared to the mixed-solvent system.
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Article title: Influence of nanomaterial fillers in biopolymer electrolyte system for squaraine-based dye-sensitized solar cells.
Authors: Stephanie Chan, Jose Paolo Bantang, Drexel Camacho
Publication title: International Journal of Electrochemical Science 10(9): 7696-7706, 2015

The vast use of fossil fuel demands the development of new sources of renewable energy. Dye-sensitized solar cells (DSSCs) have been extensively studied due to their competitive cost, ease of fabrication, high degree of tunability and relatively good-energy conversion efficiencies. The performance and stability of DSSCs are limited by leakage and solvent evaporation. This study explores the effects of nanofillers in the performance of dye-sensitized solar cells by incorporating nano-sized titanium dioxide, iron (III) oxide and halloysite fillers into the polymer electrolytes based on κ-carrageenan/DMSO/TBAI:I 2. Optimization and characterization of various concentrations of fillers were done before incorporation in solar cells. The effect of ionic conductivity and diffusion coefficient to the overall conversion efficiency of the cells were studied. The effect of squaraine dye was also investigated. The addition of various fillers to the polymer electrolyte system increased the dissociation of iodide ions and improved the ionic conductivity of the cells. The diffusion coefficient of tri-iodide ions was also greatly enhanced because of the increased volume of the system brought about by reducing polymer-polymer interaction, which increased the mobility of the redox couple (I 3-/ I-). DSSC characterization revealed a low efficiency due to a relatively high charge transfer resistances at the TiO 2 /dye/electrolyte interface.
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Article title: Initial Validation of the Chemistry Microlab kit in Facilitating Learning of Selected Chemistry Concepts for K-12 Science.
Authors: Crist John M. Pastor, Fidela Q. Aranes, Janir T. Datukan, Virgil Duad, Jose Paolo O. Bantang, Allen A. Espinosa, Nelson Garcia, Arlyne C. Marasigan, Vic Marie I. Camacho, Adolfo P. Roque, Rebecca C. Nueva España, Ruel A. Avilla, Crisanta A. Ocampo
Publication title: The Normal Lights 9(2), 2015

The introduction of the Chemistry MicroLab Kit (CμLK) aims to assist student learning of chemistry in a more interactive and practical way. Each kit was designed to address certain topics in chemistry that may otherwise be too abstract to do in a lecture-discussion set up. Among the many topics tackled in secondary school, 13 undergraduate students were hand- picked for this preliminary study. The test subjects for this initial phase of the research both majors and non-majors, were currently enrolled in a Chemistry course. It was also triedout at the Institute for Teaching and Learning (formerly Center for Teaching and Learning) with selected third year students. In this preliminary study, the students found three activities to be interesting and well-balanced: Gas Laws in a Box, Particulate Nature of Matter, and Solution Rules. In assessing the activities, they highly rated the easy language used for understanding the procedures, followed by setup of the experiments and a step-by-step presentation of the procedures. Initial results of the study find it a promising addition to the secondary level chemistry activities because CμLK enhances students’ attitudes and motivation toward chemistry laboratory work.
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