Sudip Mandal

Bio: Sudip Mandal is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Triphenylamine & Dye-sensitized solar cell. The author has an hindex of 9, co-authored 27 publications receiving 301 citations. Previous affiliations of Sudip Mandal include Vignan University & Indian Institute of Technology, Hyderabad.

Novel ethynyl-pyrene substituted phenothiazine based metal free organic dyes in DSSC with 12% conversion efficiency

Abstract: Six new dyes based on phenothiazine conjugated to an ethynyl-pyrene moiety are synthesized and characterized. Dye-sensitized solar cells are fabricated using these dyes with and without a co-adsorbent, chenodeoxychloicacid. Simple molecular engineering around the phenothiazine moiety enabled a maximum of 12% photoconversion efficiency with one of the dyes.

DFT/TD‐DFT Studies of Metal‐Free N‐Annulated Perylene Based Organic Sensitizers for Dye‐Sensitized Solar Cells: Is Thiophene Spacer Essential for Improving the DSSC Performance?

Abstract: In this study, photo-physical properties of five N-annulated perylene (NP) based metal free organic D-π-A (donor-π-linker-acceptor) sensitizers for dye-sensitized solar cells (DSSCs) have been investigated by using density functional theory (DFT/B3LYP/6-31G (d)). These dyes contain triphenylamine (TPA) derivative linked to the NP, thiophene and 2-cyanoacetic acid as electron donor, conjugated linker and acceptor. Effect of TPA, substituted TPA and the of linker on the highest occupied molecular orbital, lowest unoccupied molecular orbital and bandgap energy of these compounds have been calculated and compared against experimental values reported. The electronic absorption spectra of these dyes are studied by time-dependent density functional theory calculations. Based on the calculations, (E)-2-cyano-3-(10-(4-(diphenylamino) phenyl)-1-(2-ethylhexyl)-1H-phenanthro [1,10,9,8] carbazol-3-yl) acrylic acid (NPS-4) is identified as best dye for the DSSCs operating with I3−/I− containing electrolyte. Furthermore, chemical hardness and reorganization energy of the dyes have been calculated and analyzed, whose values predicted the electron injection ability of the dyes and hence short-circuit current density. Although, all five dyes were capable of injecting electron into the conduction band of TiO2, the highest driving force for dye regeneration, the lowest reorganization energy and the highest open-circuit voltage of the NPS-4 makes it most suitable for the DSSC application.

Electrochemically synthesized molecularly imprinted polythiophene nanostructures as recognition elements for an aspirin-chemosensor

Abstract: A chemosensor utilizing electro-polymerized film, as recognition element, has been devised and tested for selective determination of aspirin. The sensor consists of molecularly imprinted polymer (MIP) recognition elements electrodeposited as polymeric nanowires on gold-coated quartz resonator. A nanostructures were prepared by electrochemical co-polymerization of the preformed complex between the template, aspirin, the functional monomers, 3-thienylboronic acid (3-TBA) and 3-thiopheneacetic acid (3-TAA), and thiophene, which was employed as a cross-linker. This nanostructure upon leaching aspirin serve as MIP. Polymerizations were performed in acetonitrile (MIP-org) as well as a micelle-forming medium (MIP-mic). For MIP nanowire (MIP-ano) synthesis, sacrificial alumina templates were used during electro-polymerization in acetonitrile. Scanning electron microscope studies revealed compactly arranged polythiophene nanowires of uniform thickness in MIP-ano film, and MIP-mic film produced aggregated micron sized polymer structures. Density functional theoretical studies indicated a stable hydrogen bond-based complexation of aspirin by 3-TBA and 3-TAA in the pre-polymerization mixture implying that the MIP film thus prepared could selectively rebind the aspirin template. The MIP-ano-based chemosensor was sensitive towards aspirin (0.5–10 mM), over clinically relevant range (0.15–0.5 mM) under optimized FIA conditions. The sensitivity (20.62 Hz/mM) of the MIP-ano was eight and fifteen times higher than the MIP-mic (2.80 Hz/mM) and MIP-org (1.10 Hz/mM). Notably, the sensor selectively discriminates aspirin from structurally or functionally related interferants and metabolites, such as, salicylic acid, acetylsalicyloyl chloride and ibuprofen.

Functionalized Graphite Platelets and Lead Sulfide Quantum Dots Enhance Solar Conversion Capability of a Titanium Dioxide/Cadmium Sulfide Assembly

Abstract: A photoactive electrode comprising lead sulfide (PbS) and cadmium sulfide (CdS) quantum dots (QDs) and functionalized graphite platelets (FGPs) was prepared by assembling them onto titanium dioxide (TiO2), which functioned as the wide band gap semiconducting scaffold. The QDs were cumulatively capable of harvesting portions of visible and infrared regions of solar spectrum, and FGP served as electron conduit. Graphite platelets (GPs) were noncovalently functionalized using 1-pyrenecarboxylic acid (PCA) to yield FGP. The insertion of PCA between GP layers to yield few-layer graphene or FGP was confirmed by high-resolution transmission electron microscopy and Raman and X-ray photoelectron spectroscopic analyses. Fluorescence quenching, emission decay analyses, and energetics of the TiO2/FGP/PbS/CdS electrode demonstrated excited electron deactivation via a cascade mechanism. Photoexcited electrons propagate from PbS to CdS to TiO2 and to the external circuit through FGP, which had a suitably poised Fermi le...

Noncovalent Functionalization of Graphene and Graphene Oxide for Energy Materials, Biosensing, Catalytic, and Biomedical Applications

Abstract: This Review focuses on noncovalent functionalization of graphene and graphene oxide with various species involving biomolecules, polymers, drugs, metals and metal oxide-based nanoparticles, quantum dots, magnetic nanostructures, other carbon allotropes (fullerenes, nanodiamonds, and carbon nanotubes), and graphene analogues (MoS2, WS2). A brief description of π–π interactions, van der Waals forces, ionic interactions, and hydrogen bonding allowing noncovalent modification of graphene and graphene oxide is first given. The main part of this Review is devoted to tailored functionalization for applications in drug delivery, energy materials, solar cells, water splitting, biosensing, bioimaging, environmental, catalytic, photocatalytic, and biomedical technologies. A significant part of this Review explores the possibilities of graphene/graphene oxide-based 3D superstructures and their use in lithium-ion batteries. This Review ends with a look at challenges and future prospects of noncovalently modified graph...

Electrically Rechargeable Zinc–Air Batteries: Progress, Challenges, and Perspectives

Abstract: Zinc-air batteries have attracted much attention and received revived research efforts recently due to their high energy density, which makes them a promising candidate for emerging mobile and electronic applications. Besides their high energy density, they also demonstrate other desirable characteristics, such as abundant raw materials, environmental friendliness, safety, and low cost. Here, the reaction mechanism of electrically rechargeable zinc-air batteries is discussed, different battery configurations are compared, and an in depth discussion is offered of the major issues that affect individual cellular components, along with respective strategies to alleviate these issues to enhance battery performance. Additionally, a section dedicated to battery-testing techniques and corresponding recommendations for best practices are included. Finally, a general perspective on the current limitations, recent application-targeted developments, and recommended future research directions to prolong the lifespan of electrically rechargeable zinc-air batteries is provided.

Spinels: Controlled Preparation, Oxygen Reduction/Evolution Reaction Application, and Beyond

Abstract: Spinels with the formula of AB2O4 (where A and B are metal ions) and the properties of magnetism, optics, electricity, and catalysis have taken significant roles in applications of data storage, biotechnology, electronics, laser, sensor, conversion reaction, and energy storage/conversion, which largely depend on their precise structures and compositions. In this review, various spinels with controlled preparations and their applications in oxygen reduction/evolution reaction (ORR/OER) and beyond are summarized. First, the composition and structure of spinels are introduced. Then, recent advances in the preparation of spinels with solid-, solution-, and vapor-phase methods are summarized, and new methods are particularly highlighted. The physicochemical characteristics of spinels such as their compositions, structures, morphologies, defects, and substrates have been rationally regulated through various approaches. This regulation can yield spinels with improved ORR/OER catalytic activities, which can furth...

Molecularly Imprinted Polymers

Abstract: Molecularly imprinted polymers are synthetic receptors for a targeted molecule. As such, they are analogues of the natural antibody–antigen systems. In this review, after a recounting of the early history of the general field, we specifically focus on the application of these polymers as sensors. In these applications, the polymers are paired with a reporting system, which may be electrical, electrochemical, optical, or gravimetric. The presence of the targeted molecule effects a change in the reporting agent, and a calibrated quantity of the target is recorded. In this review, we describe the imprinted polymer production processes, the techniques used for reporting, and the applications of the reported sensors. A brief survey of recent applications to gas-phase sensing is included, but the focus is primarily on the development of sensors for targets in solution. Included among the applications are those designed to detect toxic chemicals, toxins in foods, drugs, explosives, and pathogens. The application...

Nonprecious Metal Catalysts for Oxygen Reduction in Heterogeneous Aqueous Systems

Abstract: A comprehensive review of recent advances in the field of oxygen reduction electrocatalysis utilizing nonprecious metal (NPM) catalysts is presented Progress in the synthesis and characterization of pyrolyzed catalysts, based primarily on the transition metals Fe and Co with sources of N and C, is summarized Several synthetic strategies to improve the catalytic activity for the oxygen reduction reaction (ORR) are highlighted Recent work to explain the active-site structures and the ORR mechanism on pyrolyzed NPM catalysts is discussed Additionally, the recent application of Cu-based catalysts for the ORR is reviewed Suggestions and direction for future research to develop and understand NPM catalysts with enhanced ORR activity are provided