Electrochemical performance of facile developed aqueous asymmetric (Fe,Cr)₂O₃//MnO₂ supercapacitor

Deshmukh, P.R.,Sohn, Youngku,Shin, Weon Gyu Elsevier 2018 ELECTROCHIMICA ACTA Vol.285 No.-

<P><B>Abstract</B></P> <P>The present study demonstrate the development of novel aqueous asymmetric supercapacitor based on polygonal integrated oxide layer ((Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB>) as the anode and spherical MnO<SUB>2</SUB> nanoparticles as the cathode. The polygonal (Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB> integrated oxide layer was obtained by the simple thermal oxidation method and low-cost, scalable chemical route was employed for the synthesis of spherical MnO<SUB>2</SUB> nanoparticles. Furthermore, electrochemical investigations of asymmetric supercapacitor (ASC) studied in aqueous electrolytes show an extended operating voltage of 1.6 and 2.0 V with the maximum specific capacitance of 34 and 37 Fg<SUP>-1</SUP> in KOH and Na<SUB>2</SUB>SO<SUB>4</SUB>, respectively. The observed energy density and power density of ASC in Na<SUB>2</SUB>SO<SUB>4</SUB> (or KOH) electrolyte is 20.89 (or 12.36) Whkg<SUP>−1</SUP> and 2173.913 (or 1739) Wkg<SUP>−1</SUP>, respectively. ASC shows the better capacitance retention over the 5000 cycles in both the electrolytes. Therefore, present study open-up new construction of inexpensive petty (Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB> anode material for the development of high energy density ASCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Preparation of (Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB> oxide layer and MnO<SUB>2</SUB> nanoparticles as a binder free electrode materials. </LI> <LI> (Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB> and MnO<SUB>2</SUB> shows the specific capacitance of 372 and 174 Fg<SUP>-1</SUP> in Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte. </LI> <LI> Development of aqueous asymmetric supercapacitor made from (Fe,Cr)<SUB>2</SUB>O<SUB>3</SUB> and MnO<SUB>2</SUB>. </LI> <LI> Asymmetric supercapacitor shows the high specific capacitance of 37 Fg<SUP>-1</SUP> in Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte. </LI> <LI> Asymmetric supercapacitor shows the high-energy density of 20.89 Whkg<SUP>−1</SUP> in Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chemical synthesis of ZnO nanorods: Investigations of electrochemical performance and photo-electrochemical water splitting applications

Deshmukh, P.R.,Sohn, Youngku,Shin, Weon Gyu Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.711 No.-

<P><B>Abstract</B></P> <P>Zinc Oxide (ZnO) nanorods were prepared by facile and inexpensive chemical route at low temperature. X-ray diffraction study confirms the formation of hexagonal wurtzite crystal structure with high orientation along the c-axis. FE-SEM images show a vertical alignment of ZnO nanorods to the substrate surface, whose average diameter and length is 1.33 and 15 μm, respectively. Electrochemical performance and photo-electrochemical water splitting of ZnO nanorods are investigated in 1 M Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte using the different electrochemical techniques. Electrochemical study of ZnO nanorods exhibits the maximum areal capacitance of 29.36 mFcm<SUP>−2</SUP> in the negative potential window, which is higher than the areal capacitance of 10.84 mFcm<SUP>−2</SUP> in the positive potential window at the scan rate of 5 mVs<SUP>−1</SUP>. ZnO nanorods show the excellent stability of 97% over the 3000 cycles in both potential windows. Photo-electrochemical water splitting demonstrates the fast photo-response with 0.098% photo-conversion efficiency.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Low temperature chemical synthesis of ZnO nanorods. </LI> <LI> Study of ZnO nanorods in electrochemical and PEC water splitting applications. </LI> <LI> ZnO nanorods exhibits the maximum areal capacitance of 29.36 mFcm<SUP>−2</SUP>. </LI> <LI> ZnO nanorods demonstrated the superb 97% stability over 3000 cycles. </LI> <LI> PEC water splitting showed the fast photoresponse and photo conversion efficiency. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

ZnO-TiO₂ core-shell nanowires decorated with Au nanoparticles for plasmon-enhanced photoelectrochemical water splitting

Park, Jinse,Deshmukh, P.R.,Sohn, Youngku,Shin, Weon Gyu Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.787 No.-

<P><B>Abstract</B></P> <P>The present work reports the development of Au-nanoparticle decorated ZnO-TiO<SUB>2</SUB> core-shell nanowires on the Si-wafer. The developed Au-nanoparticle decorated ZnO-TiO<SUB>2</SUB> core-shell nanowires exhibit a unique structure with uniform sensitization of Au-nanoparticles with the diameter in the range of 5–9 nm on the ZnO-TiO<SUB>2</SUB> core-shell heterostructure. This unique structure of Au-nanoparticle decorated ZnO-TiO<SUB>2</SUB> core-shell nanowires demonstrates an enhanced photocurrent density of 1.63 mAcm<SUP>−2</SUP> upon illumination by visible light unveiling high photoelectrochemical water splitting activity. This photocurrent density is higher than the pristine ZnO nanowires (0.51 mAcm<SUP>−2</SUP>) and ZnO-TiO<SUB>2</SUB> core-shell nanowires (1.23 mAcm<SUP>−2</SUP>). Furthermore, photoelectrochemical water splitting efficiency of Au-nanoparticle decorated ZnO-TiO<SUB>2</SUB> core-shell nanowires was found to be 0.70%, which is higher than the ZnO nanowires (0.22%) and ZnO-TiO<SUB>2</SUB> core-shell nanowires (0.53%) at the same applied potential of +0.8 V<SUB>RHE</SUB>. The improved photocurrent density and efficiency is due to the enhanced absorbance in the visible region owing to the surface plasmon resonance effect of Au-nanoparticle, effective withdrawal of hot electron from the Au-nanoparticle at the interface of metal/semiconductor due to Schottky barrier as well as excellent charge-separation and transportation originating from the core-shell nanowires.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of Au decorated ZnO-TiO<SUB>2</SUB> core-shell NWs by CVD and photo-deposition. </LI> <LI> Au decorated ZnO-TiO<SUB>2</SUB> core-shell NWs shows the photocurrent density of 1.63 mAcm<SUP>−2</SUP>. </LI> <LI> Au decorated ZnO-TiO<SUB>2</SUB> core-shell NWs shows the fast photoresponse. </LI> <LI> Au decorated ZnO-TiO<SUB>2</SUB> core-shell NWs shows photoconversion efficiency of 0.70%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation of ultrathin TiO₂ coating on boron particles by thermal chemical vapor deposition and their oxidation-resistance performance

Sung, Jinyeong,Shin, Minsang,Deshmukh, P.R.,Hyun, Hyung Soo,Sohn, Youngku,Shin, Weon Gyu Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.767 No.-

<P><B>Abstract</B></P> <P>In the present study, we have demonstrated an easy approach for the ultrathin TiO<SUB>2</SUB> coating on boron particles by simple chemical vapor deposition (CVD) method. Boron particles dispersed in ethanol and titanium tetra isopropoxide (TTIP) were delivered in the tube furnace held at 450 °C through the atomizer and bubbler, respectively where the formation of TiO<SUB>2</SUB> coated boron particles arises. The obtained TiO<SUB>2</SUB> coated boron particles were characterized with different characterization techniques, such as, transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and thermogravimetric analysis (TGA). TEM analysis shows that the boron particles are utterly covered by a thin layer TiO<SUB>2</SUB> particles and the thickness of TiO<SUB>2</SUB> layer on the surface of boron particles varies with respect to the bubbler flow rate. Moreover, TiO<SUB>2</SUB> coated boron particles represents the core-shell like structure. Amorphous nature of boron is observed from the XRD. Further, XPS and EDX analysis shows the presence of B, Ti and O elements in the obtained samples. TGA analysis demonstrate the enhanced oxidation-resistance performance of TiO<SUB>2</SUB> coated boron particles as compared to pristine boron particles, which is due to the effective protection of the boron by thin TiO<SUB>2</SUB> coating against oxidation in oxygen environment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Preparation of ultrathin TiO<SUB>2</SUB> coating on irregular shaped boron particles by thermal CVD method. </LI> <LI> Thickness of TiO<SUB>2</SUB> coating tuned by bubbler flow rate was confirmed from TEM study. </LI> <LI> TEM analysis resemble core-shell like structure of TiO<SUB>2</SUB> coated boron particle. </LI> <LI> Enhancement in oxidation-resistance performance of boron particles by means of TiO<SUB>2</SUB> coating. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Spray drying formation of metal oxide (TiO₂ or SnO₂) nanoparticle coated boron particles in the form of microspheres and their physicochemical properties

Lee, Haneol,Deshmukh, P.R.,Kim, Jong Hun,Hyun, Hyung Soo,Sohn, Youngku,Shin, Weon Gyu Elsevier 2019 JOURNAL OF ALLOYS AND COMPOUNDS Vol.810 No.-

<P><B>Abstract</B></P> <P>In the present study, metal oxide (TiO<SUB>2</SUB> or SnO<SUB>2</SUB>) nanoparticles were coated on boron particles using a facile spray drying technique. The coating of metal oxide nanoparticles on the boron surface was varied by changing the weight ratio of metal oxide nanoparticles to boron particles. The crystalline structure of the metal oxide nanoparticles was mainly retained without any additional phase formation on the metal oxide coated boron particles, as identified by XRD. FIB-SEM images showed that the TiO<SUB>2</SUB> or SnO<SUB>2</SUB> coated boron particles formed microspheres with diameters between 5 and 10 μm. FIB-cross sectional images indicated the microspheres had a porous structure, and every individual boron particle was coated by metal oxide nanoparticles. The line scanning profile, elemental mapping and corresponding EDAX spectra results indicated the boron particles were well coated with metal oxide nanoparticles, and confirmed the presence of respective elements in the samples, respectively. TEM study showed the fine coating of metal oxide nanoparticles on the surface of the boron particles. The surface elemental composition was identified with XPS, and revealed the strong interaction between the metal oxide and boron particles. The thermal behavior of the boron, metal oxide and metal oxide nanoparticle coated boron particles was studied in the presence of nitrogen and air atmosphere using thermogravimetric analysis. The TGA of the metal oxide nanoparticle coated boron particles showed enhanced oxidation-resistance performance in the presence of air atmosphere.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Metal oxide nanoparticle coating on boron particles using spray-drying technique. </LI> <LI> Porous microspheres of metal oxide nanoparticle coated boron particles. </LI> <LI> Well distribution and coating of metal oxide nanoparticles on the boron particles. </LI> <LI> Enhanced oxidation-resistance performance of metal oxide coated boron particles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Room temperature electroless Ni-coating on boron particles: Physicochemical and oxidation-resistance properties

P.R. Deshmukh,Youngku Sohn,Weon Gyu Shin 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.91 No.-

Ni nanoparticles were coated on irregularly shaped micron sized boron particles by facile electroless Nidepositionmethod. Four kinds of Ni-coated boron particles were prepared using four different simplepaths during the electroless deposition process: no rinsing and no drying (Path A), only drying (Path B),both rinsing and drying (Path C), and only rinsing (Path D). Surface morphology confirmed the Ninanoparticlescoating on the surface of boron particles. The size of the Ni nanoparticles varied between 10and 120 nm with respect to the chosen paths used for preparation. The Ni nanoparticle's size was alsostudied using TEM and found to be consistent with the surface morphology results. XRD measurement ofthe Ni-coated boron particles showed the formation of crystalline Ni nanoparticles. EDAX and XPS resultsshowed the presence of the primary B and Ni elements in the obtained samples. Thermogravimetricanalysis conducted in air atmosphere found the boron particles had enhanced oxidation resistance afterthe coating of Ni nanoparticles. The Ni-coated boron particles showed a shift in exothermic peak to alower temperature and higher heat evolution than the pure boron, recommending the use of Ni-coatedboron particles in solid fuel in missile/rocket engines, and high temperature applications.

Growth of Polyaniline Nanofibers for Supercapacitor Applications Using Successive Ionic Layer Adsorption and Reaction (SILAR) Method

P. R. Deshmukh,S. N. Pusawale,N. M. Shinde,C.D. Lokhande 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.1

We report the synthesis of polyaniline nanofibers using the successive ionic layer adsorptionand reaction (SILAR) method. The structural study shows the amorphous nature of polyaniline. The formation of polyaniline nanofibers has been revealed by scanning electron microscopy (SEM)whereas the confirmation of polyaniline material is obtained from Fourier transform infrared (FT-IR)spectroscopy. A plausible explanation illustrating the growth mechanism is presented. A maximumspecific capacitance of 1078 F.g−1 at a scan rate of 5 mV.s−1 is obtained. The charge-dischargebehavior shows a maximum specific power of 1.2 kW.kg−1 and specific energy of 64 Wh.kg−1. The ease of the synthesis and the interesting electrochemical properties indicate that polyanilinenanofibers are promising materials for supercapacitor applications.

A Facile Synthesis of 1,3,4,6-Tetrahydro-1,6-benzodiazocine-2,5-diones

S.R.Bhusare,D.V.Jarikote,R.R.Deshmukh,W.N.Jadhav,R.P.Pawar,Y.B.Vibhute 대한화학회 2003 Bulletin of the Korean Chemical Society Vol.24 No.9

A Facile Synthesis of 1,3,4,6-Tetrahydro-1,6-benzodiazocine-2,5-diones

Bhusare, S. R.,Jarikote, D. V.,Deshmukh, R. R.,Jadhav, W. N.,Pawar, R. P.,Vibhute, Y. B. Korean Chemical Society 2003 Bulletin of the Korean Chemical Society Vol.24 No.9

Electrochromic performance of the mixed V2O5eWO3 thin films synthesized by pulsed spray pyrolysis technique

C.E. Patil,N.L. Tarwal,P.R. Jadhav,P.S. Shinde,H.P. Deshmukh,J.D. Song,A.V. Moholkar,M.G. Gang,김진혁,P.S. Patil 한국물리학회 2014 Current Applied Physics Vol.14 No.3

Vanadium pentoxide (V2O5) mixed tungsten trioxide (WO3) thin films have been synthesized by a novel pulsed spray pyrolysis technique (PSPT) on glass and fluorine doped tin oxide (FTO) coated glass substrates at 400 C. Aqueous solutions of equimolar vanadium chloride and ammonium tungstate were mixed in volume proportions (5%, 10% and 15%) for the deposition of V2O5eWO3 thin films. The structural, morphological, optical and electrochemical properties of V2O5eWO3 thin films were investigated by FT-IR, XRD, SEM, cyclic voltammetry, chronoamperometry and chronocoulometry techniques. The results showed that the electrochemical properties of V2O5 were altered by mixing WO3. All the films exhibited cathodic electrochromism in lithium containing electrolyte (0.5 M LiClO4 þ propylene carbonate (PC)). Maximum coloration efficiency (CE) of about 49 cm2 C1 was observed for the V2O5 film mixed with 15% WO3. The electrochemical stability of the sample was examined and it was found to be stable up to 1000 cycles.