CuS thin film grown using the one pot, solution-process method for dye-sensitized solar cell applications

Patil, Supriya A.,Mengal, Naveed,Memon, Anam Ali,Jeong, Sung Hoon,Kim, Hak-Sung ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.708 No.-

<P><B>Abstract</B></P> <P>The counter electrode has a great influence on the performance of dye-sensitized solar cells (DSSCs). In this work, efforts have been made to develop a platinum (Pt)-free, low-cost, copper sulfide (CuS) counter electrode for application in DSSCs. CuS thin film was successfully grown on a conducting and non-conducting substrate using a low temperature, one pot, solution-process method. The as-synthesized CuS thin film was utilized in the DSSCs as a counter electrode (CE). The CE demonstrated good electrocatalytic properties and a photoconversion efficiency (PCE) of 5.03% when used in DSSCs. It was also comparable with devices made using platinum counter electrodes. Synthesized CuS thin film with excellent electrocatalytic properties could serve as an alternative counter electrode in DSSC fabrication.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuS thin film shows excellent architecture, and unique half-sheet shape like morphology. </LI> <LI> Solution process synthesized CuS thin film shows high crystallinity at room temperature without external heat treatments. </LI> <LI> The CuS thin film shows good electrocatalytic properties and the resultant used as counter electrode in DSSCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A simple, room temperature, solid-state synthesis route for metal oxide nanostructures

Patil, Supriya A.,Shinde, Dipak V.,Ahn, Do Young,Patil, Dilip V.,Tehare, Kailas K.,Jadhav, Vijaykumar V.,Lee, Joong K.,Mane, Rajaram S.,Shrestha, Nabeen K.,Han, Sung-Hwan The Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.33

<P>In this work, we demonstrate an extremely simple but highly effective strategy for the synthesis of various functional metal oxides (MOs) such as ZnO, In2O3, Bi2O3, and SnO2nanoparticles with various distinct shapes at room temperature<I>via</I>a solid-state reaction method. The method involves only mixing and stirring of the corresponding metal salt and NaOH together in the solid phase, which yields highly crystalline metal oxides within 5-10 min of reaction time. The obtained paste can be directly doctor-bladed onto a variety of substrates for photoelectrochemical applications. The crystal structure and surface composition of the MOs are obtained by X-ray diffraction patterns, energy dispersive analysis and X-ray photoelectron spectroscopy, respectively. The surface morphology is confirmed from the scanning electron microscopy surface photo-images. The surface area and pore size distribution are studied by the N2adsorption method. As a proof-of-concept demonstration for the application, ZnO nanoplate structures are envisaged in DSSCs as photoanodes, which enables us to obtain excellent photovoltaic properties with a power conversion efficiency of 5%. The proposed method does not require a sophisticated instrumental setup or harsh conditions, and the method is easily scalable. Hence, it can be applied for the cost-effective and large-scale production of MO nanoparticles with high crystallinity.</P>

An ion exchange mediated shape-preserving strategy for constructing 1-D arrays of porous CoS_1.0365 nanorods for electrocatalytic reduction of triiodide

Patil, Supriya A.,Shinde, Dipak V.,Lim, Iseul,Cho, Keumnam,Bhande, Sambhaji S.,Mane, Rajaram S.,Shrestha, Nabeen K.,Lee, Joong Kee,Yoon, Tae Hyun,Han, Sung-Hwan The Royal Society of Chemistry 2015 Journal of Materials Chemistry A Vol.3 No.15

<▼1><P>A solution based ion exchange mediated strategy for constructing 1-D arrays of porous CoS1.0365 nanorod film from analogous 1-D array of Co3O4 film derived from pyrolysis of nanostructured cobalt hydroxycarbonate film.</P></▼1><▼2><P>Based on a coordination chemistry approach, the present work reports on the synthesis of thin films of various cobalt hydroxycarbonate nanostructures such as nanobeams, nanoneedles, and bending nanorods using three different cobalt precursors <I>viz.</I> Cl<SUP>−</SUP>, NO3<SUP>−</SUP> and CH3COO<SUP>−</SUP>. After pyrolysis in air, the hydroxycarbonate nanostructures are transferred into 1-D arrays of Co3O4 nanorods. The obtained 1-D Co3O4 nanostructures are then transformed into the corresponding analogous shaped 1-D arrays of porous cobalt sulfide (CoS1.0365) nanostructures using a wet chemical transformation method based on an ion exchange approach. The nanostructured films before and after the ion exchange reaction are characterized using field emission electron scanning microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma mass spectroscopy (ICP-MS) measurements. As a proof-of-concept demonstration for the application, various shaped CoS1.0365 nanorod films synthesized are investigated as a Pt-free counter electrode in dye-sensitized-solar cells (DSSCs). The influence of three different counter anions of the cobalt precursors on the structural, textural, and morphological aspects, and thereby their influence on electronic and electrochemical properties, has been investigated. A correlation among electrical conductivity, charge transfer resistance and electrocatalytic performance of various CoS1.0365 nanorod films obtained from different cobalt precursors has been established. Among the various nanostructures, the thicker nanorod film synthesized using a chloride precursor has demonstrated the best electrocatalytic behavior toward triiodide reduction, which led to a short circuit current density of 18.04 mA cm<SUP>−2</SUP> and energy conversion efficiency of 7.4% of the DSSC. This photovoltaic performance is highly competitive to a current density of 18.26 mA cm<SUP>−2</SUP> and energy conversion efficiency of 7.7% exhibited by the standard Pt counter electrode.</P></▼2>

Formation of Semimetallic Cobalt Telluride Nanotube Film via Anion Exchange Tellurization Strategy in Aqueous Solution for Electrocatalytic Applications

Patil, Supriya A.,Kim, Eun-Kyung,Shrestha, Nabeen K.,Chang, Jinho,Lee, Joong Kee,Han, Sung-Hwan American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.46

<P>Metal telluride nanostructures have demonstrated several potential applications particularly in harvesting and storing green energy. Metal tellurides are synthesized by tellurization process performed basically at high temperature in reducing gas atmosphere, which makes the process expensive and complicated. The development of a facile and economical process for desirable metal telluride nanostructures without complicated manipulation is still a challenge. In an effort to develop an alternative strategy of tellurization, herein we report a thin film formation of self-standing cobalt telluride nanotubes on various conducting and nonconducting substrates using a simple binder-free synthetic strategy based on anion exchange transformation from a thin film of cobalt hydroxycarbonate nanostructures in aqueous solution at room temperature. The nanostructured films before and after ion exchange transformation reaction are characterized using field emission scanning electron microscope, energy dispersive X-ray analyzer, X-ray photoelectron spectroscopy, thin film X-ray diffraction technique, high resolution transmission electron microscope, and selected area electron diffraction analysis technique. After the ion exchange transformation of nanostructures, the film shows conversion from insulator to highly electrical conductive semimetallic characteristic. When used as a counter electrode in I<SUB>3</SUB><SUP>–</SUP>/I<SUP>–</SUP> redox electrolyte based dye-sensitized solar cells, the telluride film exhibits an electrocatalytic reduction activity for I<SUB>3</SUB><SUP>–</SUP> with a demonstration of solar-light to electrical power conversion efficiency of 8.10%, which is highly competitive to the efficiency of 8.20% exhibited by a benchmarked Pt-film counter electrode. On the other hand, the telluride film electrode also demonstrates electrocatalytic activity for oxygen evolution reaction from oxidation of water.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-46/acsami.5b08501/production/images/medium/am-2015-085018_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b08501'>ACS Electronic Supporting Info</A></P>

Determination of lithium diffusion coefficient and reaction mechanism into ultra-small nanocrystalline SnO₂ particles

Ali, Ghulam,Patil, Supriya A.,Mehboob, Sheeraz,Ahmad, Mashkoor,Ha, Heung Yong,Kim, Hak-Sung,Chung, Kyung Yoon Elsevier 2019 Journal of Power Sources Vol.419 No.-

<P><B>Abstract</B></P> <P>High-performance electrode materials for lithium-ion batteries (LIBs) are urgently required to meet the requirement of the widespread use of energy storage devices from small-to large-scale applications. In this regard, ultra-small nanocrystalline SnO<SUB>2</SUB> particles with a size of ∼3 nm are synthesized using a simple hydrothermal method and investigated as a high capacity anode material for LIBs. The SnO<SUB>2</SUB> anode shows a high reversible capacity of 1026 mAh g<SUP>−1</SUP> at a current density of 150 mA g<SUP>−1</SUP>. The kinetic study of the anode material is conducted and compared using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic intermittent titration techniques and the lithium diffusion coefficient at open circuit potential is calculated to be 3.71978 × 10<SUP>−13</SUP>, 1.818 × 10<SUP>−14</SUP>, and ∼1.82 × 10<SUP>−16</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>, respectively. The reaction mechanism of highly reversible SnO<SUB>2</SUB> nanoparticles is investigated using ex-situ XRD, XPS, in-situ X-ray absorption near edge spectroscopy, and TEM and the results reveal the formation of lithium-tin alloy in the lithiated electrode and reversible formation of SnO<SUB>2</SUB> upon delithiation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ultra-small nanocrystalline SnO<SUB>2</SUB> particles with a size of 3 nm are synthesized. </LI> <LI> SnO<SUB>2</SUB> nanocrystalline electrode shows a specific capacity of 1026 mAh g<SUP>−1</SUP>. </LI> <LI> This electrode delivers a 350 mAh g<SUP>−1</SUP> at a high current density of 2 A g<SUP>−1</SUP>. </LI> <LI> Li kinetic study was performed and compared using CV, EIS, and GITT. </LI> <LI> The reaction mechanism was revealed using ex-situ XRD, XPS, and TEM. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Intense pulse flash white light combined with deep UV irradiation sintering of ZnO nanosheets for dye sensitized solar cell application

Supriya A.Patil,Hyun-Jun Hwang,Myeoung-Hyun Yu,Hak-Sung Kim 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.4

Synthesis and Characterization of Copper Nanoparticles (Cu-Nps) using Rongalite as Reducing Agent and Photonic Sintering of Cu-Nps Ink for Printed Electronics

Supriya A. Patil,류정현,김학성 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.2

Copper nanoparticles (Cu-Nps) are one of the promising material for the advancement of nanoscience and technology. In this work, we successfully synthesized Cu-Nps using sodium hydroxymethanesulinate (Rongalite) as a novel reducing agent via solution process. Cu-Nps were achieved from chemical reduction of copper salt within 10-20 min at low temperature without using any complexing agent. In order to investigate the phase, size, and composition of the synthesized Cu-Nps, X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were employed. Average particle size of the synthesized Cu-Nps is 152 nm. It is expected that the outcomes of this study take a step closer towards designing general strategies for a simple, environment friendly and low cost synthesis method of Cu-Nps. The synthesized Cu-Nps are mixed with commercial Cu-Nps and sintered using photonic sintering process. To determine the optimum sintering energy, the flash light irradiation energy was varied and optimized. An XRD and SEM were used to characterize the sintered Cu-Nps. The resulting sintered Cu-Nps exhibited a low resistivity (20.73 μΩcm) without any damages of the polymer substrate.

Synthesis of solution processed f-CNT@Bi₂S₃ hybrid film coated linen fabric as a free-standing textile structured photo catalyst

Memon, Anam Ali,Arbab, Alvira Ayoub,Patil, Supriya A.,Mengal, Naveed,Sun, Kyung Chul,Sahito, Iftikhar Ali,Jeong, Sung Hoon,Kim, Hak Sung Elsevier 2018 Applied catalysis. A, General Vol.566 No.-

<P><B>Abstract</B></P> <P>A unique metallic carbon hybrid film, synthesized with synchronized distribution of bismuth sulfide (Bi<SUB>2</SUB>S<SUB>3</SUB>) and exfoliated multiwall carbon nanotubes (MWCNTs), has been proposed for use as freestanding textile electrodes in photo catalysts. The defect-rich morphology of Bi<SUB>2</SUB>S<SUB>3</SUB> nanowire decorated MWCNT hybrid enhances the photocatalytic activity, electronic properties, cyclic stability, and electron pathways. The proposed f-CNT@Bi<SUB>2</SUB>S<SUB>3</SUB>-hybrid linen fabric electrode demonstrated a defect-rich morphology synchronized with high electrical conductivity. These properties greatly enhanced the photocatalytic activity and electron transfer. The high photocatalytic activity is attributed to the synergistic effect of the high electron affinity of MWCNTs and the structural distortion caused by Bi<SUB>2</SUB>S<SUB>3</SUB> nanowires. Degradation of methylene blue dye was accelerated owing to the elevated activity of Bi<SUB>2</SUB>S<SUB>3</SUB> nanowires, which provides fast absorption of contaminants and reduction of oxidative species. Our proposed system of metallic carbon freestanding textile electrode opens the broad applications of textile-based photochemical devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A flexible and highly conductive linen fabric is fabricated. </LI> <LI> The fabric is coated with carbon metallic films by doctor blade technique. </LI> <LI> The electrode is durable and highly photocatalytic active. </LI> <LI> The electrode is stable at various bending positions, against water and electrolyte. </LI> <LI> The surface resistance of the carbon metallic films coated fabric is only 19 Ω sq<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Facile and cost-effective methodology to fabricate MoS₂ counter electrode for efficient dye-sensitized solar cells

Vikraman, Dhanasekaran,Patil, Supriya A.,Hussain, Sajjad,Mengal, Naveed,Kim, Hyun-Seok,Jeong, Sung Hoon,Jung, Jongwan,Kim, Hak-Sung,Park, Hui Joon Elsevier 2018 Dyes and pigments Vol.151 No.-

<P><B>Abstract</B></P> <P>Interests in the development of economical and high-efficiency counter electrodes (CEs) of dye-sensitized solar cell (DSSC) to replace the excessively cost and scarce platinum (Pt) CEs have been increased. In this report, we demonstrate a facile chemical bath deposition (CBD) route to prepare layered MoS<SUB>2</SUB>/fluorine-doped tin oxide (FTO) films that directly act as the CEs of DSSCs. A DSSC containing the CBD-synthesized MoS<SUB>2</SUB>/FTO CE (prepared at 0.03 M Mo source concentration, 90 °C bath temperature and 30 min deposition time) exhibits high power conversion efficiency (PCE) of 7.14%, which is approaching that of DSSC with Pt/FTO CE (8.73%). The electrocatalytic activity of the MoS<SUB>2</SUB>/FTO and Pt/FTO CEs are discussed in detail with their cyclic voltammetry (CV), Tafel polarization curves, and electrochemical impedance spectra (EIS). The observed results indicate that our low-cost CE has a high electrocatalytic activity for the reduction of triiodide to iodide and a low charge transfer resistance at the electrolyte–electrode interface with a comparable state to that of a Pt/FTO CE.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Crystalline MoS<SUB>2</SUB> thin layers are grown on FTO using chemical bath deposition (CBD) method. </LI> <LI> The structural and optical properties of the synthesized MoS<SUB>2</SUB> layers are systematically investigated. </LI> <LI> The electrocatalytic activity of the CBD-synthesized MoS<SUB>2</SUB>/FTO is discussed with their CV, Tafel and EIS curves. </LI> <LI> A DSSC containing the MoS<SUB>2</SUB>/FTO CE exhibits high power conversion efficiency of 7.14%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

CuS/WS₂ and CuS/MoS₂ heterostructures for high performance counter electrodes in dye-sensitized solar cells

Hussain, Sajjad,Patil, Supriya A.,Memon, Anam Ali,Vikraman, Dhanasekaran,Naqvi, Bilal Abbas,Jeong, Sung Hoon,Kim, Hyun-Seok,Kim, Hak-Sung,Jung, Jongwan Elsevier 2018 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.171 No.-

<P><B>Abstract</B></P> <P>In this work, we demonstrated CuS/WS<SUB>2</SUB> and CuS/MoS<SUB>2</SUB> heterostructures via a sputtering-CVD process for dye-sensitized solar cells (DSSCs) as a counter electrode (CE) to replace the currently preferred expensive platinum (Pt). The cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel curve studies revealed that the unique CuS/WS<SUB>2</SUB> and CuS/MoS<SUB>2</SUB> heterostructures were beneficial in achieving high electrocatalytic activity, low charge-transfer resistance at the CE/electrolyte interface, and fast reaction kinetics for the reduction of triiodide to iodide at the CE. The constructed DSSCs using these CuS/WS<SUB>2</SUB> and CuS/MoS<SUB>2</SUB> CEs exhibited high-power conversion efficiencies (PCEs) of 8.21% and 7.12%, respectively, which are comparable to conventional Pt CE (8.74%) and pristine WS<SUB>2</SUB>, MoS<SUB>2</SUB>, and CuS CEs (6.0%, 6.3% and 6.4%). This novel sulfur based heterostructure opens up opportunities for a variety of optoelectronic and photoelectrochemical applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuS/WS<SUB>2</SUB> heterostructure was synthesized via a sputtering-CVD process for counter electrode in DSSCs. </LI> <LI> It showed low charge transfer resistance, good electrocatalytic activity and strong electrochemical stability. </LI> <LI> The constructed DSSC using CuS/WS<SUB>2</SUB> CE achieved high power conversion efficiency of 8.21% </LI> <LI> That value is comparable to that of Pt CE (8.74%) and higher than that of pristine WS<SUB>2</SUB>, MoS<SUB>2</SUB>, and CuS CEs. </LI> <LI> CuS/WS<SUB>2</SUB> CE shows promising counter electrode for DSSCs. </LI> </UL> </P>