Improved Photoelectrochemical Cell Performance of Tin Oxide with Functionalized Multiwalled Carbon Nanotubes–Cadmium Selenide Sensitizer

Bhande, Sambhaji S.,Ambade, Rohan B.,Shinde, Dipak V.,Ambade, Swapnil B.,Patil, Supriya A.,Naushad, Mu.,Mane, Rajaram S.,Alothman, Z. A.,Lee, Soo-Hyoung,Han, Sung-Hwan American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.45

<P>Here we report functionalized multiwalled carbon nanotubes (<I>f</I>-MWCNTs)–CdSe nanocrystals (NCs) as photosensitizer in photoelectrochemical cells, where <I>f</I>-MWCNTs were uniformly coated with CdSe NCs onto SnO<SUB>2</SUB> upright standing nanosheets by using a simple electrodeposition method. The resultant blended photoanodes demonstrate extraordinary electrochemical properties including higher Stern–Volmer constant, higher absorbance, and positive quenching, etc., caused by more accessibility of CdSe NCs compared with pristine SnO<SUB>2</SUB>–CdSe photoanode. Atomic and weight percent changes of carbon with <I>f</I>-MWCNTs blending concentrations were confirmed from the energy dispersive X-ray analysis. The morphology images show a uniform coverage of CdSe NCs over <I>f</I>-MWCNTs forming a core–shell type structure as a blend. Compared to pristine CdSe, photoanode with <I>f</I>-MWCNTs demonstrated a 257% increase in overall power conversion efficiency. Obtained results were corroborated by the electrochemical impedance analysis. Higher scattering, more accessibility, and hierarchical structure of SnO<SUB>2</SUB>-<I>f</I>-MWCNTs-blend–CdSe NCs photoanode is responsible for higher (a) electron mobility (6.89 × 10<SUP>–4</SUP> to 10.89 × 10<SUP>–4</SUP> cm<SUP>2</SUP> V<SUP>–1</SUP> S<SUP>1–</SUP>), (b) diffusion length (27 × 10<SUP>–6</SUP>), (c) average electron lifetime (32.2 ms), and transit time (1.15 ms).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-45/acsami.5b05385/production/images/medium/am-2015-05385e_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am5b05385'>ACS Electronic Supporting Info</A></P>

Direct successive ionic layer adsorption and reaction (SILAR) synthesis of nickel and cobalt hydroxide composites for supercapacitor applications

Lee, Damin,Xia, Qi Xun,Mane, Rajaram S.,Yun, Je Moon,Kim, Kwang Ho ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.722 No.-

<P><B>Abstract</B></P> <P>Mesoporous nickel and cobalt hydroxide composites are directly grown onto 3D macro-porous Ni foam as a binder-free electrode for supercapacitors by using the successive ionic layer adsorption and reaction (SILAR) method. This method is the cheapest and simplest among several deposition processes for supercapacitor applications. An as-obtained porous NiCo(OH)<SUB>2</SUB> electrode exhibits a remarkable specific capacity (1113.6 mAh g<SUP>−1</SUP> at a current density of 3 A g<SUP>−1</SUP>) and excellent cycling stability (85.62% capacity retention after 5000 cycles). Furthermore, an asymmetric supercapacitor assembled with NiCo(OH)<SUB>2</SUB> as a positive electrode and graphene as a negative electrode shows a high energy density of 20.07 W h kg<SUP>−1</SUP> at a power density of 2302.73 W kg<SUP>−1</SUP> and excellent cycling stability (76.46% retention after 5000 cycles). As a result, it shows that the NiCo(OH)<SUB>2</SUB> fabricated by the SILAR method can be a promising electrode towards energy-storage devices with high energy and power densities.</P> <P><B>Highlights</B></P> <P> <UL> <LI> SILAR method is a process conducted under mild conditions for 30 s. </LI> <LI> NiCo(OH)<SUB>2</SUB> composite by SILAR method is a 3D flower-like porous nanostructure. </LI> <LI> The synthesized NiCo(OH)<SUB>2</SUB> electrode shows high electrochemical performances. </LI> <LI> The specific capacity of the NiCo(OH)<SUB>2</SUB> electrode is 1113.6 mAh g<SUP>−1</SUP> at 3 A g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Multiple band gap energy layered electrode for photoelectrochemical cells

S.S. Kale,Rajaram S. Mane,T. Ganesh,B.N. Pawar,한성환 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Using wet chemistry, electrode of multiple band gap energy starting from wide titanium dioxide (TiO2) to narrow range cadmium selenide (CdSe) is synthesized. Complete utilization of solar spectrum by initializing the film of wide band gap energy (absorbs high energy photons) permitting to narrow band gap films (absorbs low energy photons), is explored in the manuscript. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectrophotometer techniques were used for the structural, surface morphological and optical studies. The role of every layer of descending band gap energy on the performance of photoelectrochemical cells is demonstrated. The three layered electrode exhibits a good absorbance followed by photoresponse as compared to the bilayers. Using wet chemistry, electrode of multiple band gap energy starting from wide titanium dioxide (TiO2) to narrow range cadmium selenide (CdSe) is synthesized. Complete utilization of solar spectrum by initializing the film of wide band gap energy (absorbs high energy photons) permitting to narrow band gap films (absorbs low energy photons), is explored in the manuscript. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectrophotometer techniques were used for the structural, surface morphological and optical studies. The role of every layer of descending band gap energy on the performance of photoelectrochemical cells is demonstrated. The three layered electrode exhibits a good absorbance followed by photoresponse as compared to the bilayers.

Dye-sensitized solar cell and electrochemical supercapacitor applications of electrochemically deposited hydrophilic and nanocrystalline tin oxide film electrodes

Rajaram S. Mane,장진호,Dukho Ham,B.N. Pawar,T. Ganesh,한성환,이준기,조병원 한국물리학회 2009 Current Applied Physics Vol.9 No.1

The present article demonstrates the use of low-cost electrochemically synthesized hydrophilic and nanocrystalline tin oxide film electrodes at room temperature in dye-sensitized solar cells and electrochemical supercapacitors. A mixed phase of tin instead of single phase composed of uniformly distributed irregular spherical grains in a nanometer regime scale was obtained. Tin oxide film electrode showed efficient photoperformance when subjected to dye-sensitized solar cells. The interfacial and specific capacitances of 118.4 μF/㎠ and 43.07 F/g, respectively, in 0.1 M NaOH electrolyte were confirmed from cyclic-voltammetry measurement. The present article demonstrates the use of low-cost electrochemically synthesized hydrophilic and nanocrystalline tin oxide film electrodes at room temperature in dye-sensitized solar cells and electrochemical supercapacitors. A mixed phase of tin instead of single phase composed of uniformly distributed irregular spherical grains in a nanometer regime scale was obtained. Tin oxide film electrode showed efficient photoperformance when subjected to dye-sensitized solar cells. The interfacial and specific capacitances of 118.4 μF/㎠ and 43.07 F/g, respectively, in 0.1 M NaOH electrolyte were confirmed from cyclic-voltammetry measurement.

Controlled repeated chemical growth of ZnO films for dye-sensitized solar cells

Rajaram S. Mane,이원주,C.D. Lokhande,조병원,한성환 한국물리학회 2008 Current Applied Physics Vol.8 No.5

The controlled growth of ZnO nanorods perpendicular to substrate surface i.e. c-axis by a repeated chemical deposition method for efficient dye-sensitized solar cell application is described. X-ray diffraction study shows the wurtzite structure of ZnO with high crystallinity. Intensity and newly evolved peaks of the ZnO are found to be thickness dependent. Dye loving flower-like globular architecture of ZnO is observed after 8 lm thickness. Dye-sensitized solar cell studies show the solar-to-electrical conversion efficiency of 2.21% for 11 lm ZnO electrode when illuminated with 80 mW/cm2.

Large area (9×9cm²) electrostatically sprayed nanocrystalline zincite thin films for hydrogen production application

Gaikwad, Rajendra S.,Chae, Sang-youn,Mane, Rajaram S.,Cai-Gangri, Rajaram S.,Han, Sung-Hwan,Joo, Oh-Shim Elsevier 2010 International journal of hydrogen energy Vol.35 No.13

<P><B>Abstract</B></P><P>Synthesis of single phase nanocrystalline zinc ferrite (zincite) thin films that provides high surface area for active redox reactions is reported. Electrostatic spray method is employed for obtaining these ferrite films onto a stainless steel substrate of 9×9cm<SUP>2</SUP> area using zinc acetate and iron nitrate precursor solutions, mixed in 1:1.5 proportions in triply-distilled water. Single zinc ferrite phase in films, confirmed from the X-ray diffraction pattern, reveals the aggregation of several nanometer-sized spherical grains. About 4nm average roughness is obtained from the 3D AFM image. Zinc ferrite film deposited onto a glass substrate shows both direct (2.96eV) and indirect (1.92eV) band gap energies. Hydrophilic behavior that might facilitate easy reaction kinetics in a water splitting process is noticed. Finally, 450mL/h hydrogen production rate is confirmed when zinc ferrite film electrode was used as an anode in presence of Pt mesh as a cathode.</P>

Low-Temperature Solution-Processed Thiophene-Sulfur-Doped Planar ZnO Nanorods as Electron-Transporting Layers for Enhanced Performance of Organic Solar Cells

Ambade, Swapnil B.,Ambade, Rohan B.,Bagde, Sushil S.,Eom, Seung Hun,Mane, Rajaram S.,Shin, Won Suk,Lee, Soo-Hyoung American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.4

<P>1-D ZnO represents a fascinating class of nanostructures that are significant to optoelectronics. In this work, we investigated the use of an eco-friendly, metal free in situ doping through a pure thiophene-sulfur (5) on low temperature processed (<95 degrees C) and annealed (<170 degrees C), planar 1-D ZnO nanorods (ZnRs) spin-coated as a hole blocking and electron transporting layer (ETL) for inverted organic solar cells (iOSCs). The TEM, HRTEM, XPS, FT-IR, EDS and Raman studies clearly reveal that the thiophene-S (Thi-S) atom is incorporated on planar ZnRs. The investigations in electrical properties suggest the enhancement in conductivity after Thi-S doping on 1-D ZnRs. The iOSCs of poly.(3-hexylthiophene-2,5-diyl) and phenyl-C-61-butyric acid methyl ester (P3HT: PC60BM) photoactive layer containing thiophene-S doped planar ZnRs (Thi-S-PZnRs) as ETL exhibits power conversion efficiency (PCE) of 3.68% under simulated AM 1.5 G, 100 mW cm(-2) illumination. The similar to 47% enhancement in PCE compared with pristine planar ZnRs (PCE = 2.38%) ETL is attributed to a combination of desirable energy level alignment, morphological modification, increased conductivity and doping effect. The universality of Thi-S-PZnRs ETL is demonstrated by the highest PCE of 8.15% in contrast to 6.50% exhibited by the iOSCs of ZnRs ETL for the photoactive layer comprising of poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b;4,5-b]dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)] : phenyl-C71-butyric acid methyl ester (PTB7-Th: PCB71M). This enhancement in PCE is observed to be driven mainly through improved photovoltaic parameters like fill factor (ff) as well as photocurrent density (J(sc)), which are assigned to increased conductivity, exciton dissociation, and effective charge extraction, while; better ohmic contact, reduced charge recombination, and low leakage current density resulted in increased Voc.</P>

Upright-standing ZnO nano-sheets growth using wet chemistry

김선기,Rajaram S. Mane,주오심,T. Ganesh,조병원,한성환 한국물리학회 2009 Current Applied Physics Vol.9 No.3

Room temperature solution processing is used for cross-linked upright-standing ZnO nano-sheets growth of ~2–5 ㎛ in length and ~100–150 nm in width. These nano-sheets are characterized for structural and surface morphological analyses. Energy dispersive X-ray spectrum is preferred to chemical analysis. Confirmation of well defined, cross-linked and distinct ZnO nano-sheets of quoted dimensions is carried out using a scanning electron microscopy. Porous nature of nano-sheets with fine edge boundaries is noted from low resolution transmission electron microscopy. Room temperature solution processing is used for cross-linked upright-standing ZnO nano-sheets growth of ~2–5 ㎛ in length and ~100–150 nm in width. These nano-sheets are characterized for structural and surface morphological analyses. Energy dispersive X-ray spectrum is preferred to chemical analysis. Confirmation of well defined, cross-linked and distinct ZnO nano-sheets of quoted dimensions is carried out using a scanning electron microscopy. Porous nature of nano-sheets with fine edge boundaries is noted from low resolution transmission electron microscopy.

Room temperature synthesis of nanostructured mixed-ordered-vacancy compounds (OVCs) and chalcopyrite CuInSe₂ (CIS) thin films in alkaline chemical bath

Sharma, Ramphal,Mane, Rajaram S,Ghule, Gangri Cai Anil,Ham, Duk-Ho,Min, Sun-Ki,Lee, Seung-Eon,Han, Sung-Hwan Institute of Physics [etc.] 2009 Journal of Physics. D, Applied Physics Vol.42 No.5

<P>Room temperature synthesis of ordered-vacancy-compounds (OVCs) and copper indium diselenide (CuInSe<SUB>2</SUB>, CIS) by cation and anion exchange reactions of solid CdS thin films with CIS ionic solution in an alkaline chemical bath is reported. The growth parameters such as pH, deposition time and concentration of the solutions were optimized to achieve uniform thin films. Nanostructured CdS thin films (150 nm thick) prepared by chemical bath deposition are used for the deposition of OVC and CIS thin films. The ion exchange reaction between the CdS thin film and the CIS ionic solutions transforms the yellow colour CdS film into faint black, indicating the formation of OVC and CIS film. The resultant films were annealed in air at 200 °C for 1 h and further subjected to characterization using the x-ray diffraction, transmission electron microscopy, energy dispersive x-ray analysis, x-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, optical absorption and electrical measurement techniques. The OVC and CuIn<SUB>3</SUB>Se<SUB>5</SUB> nanodomains are observed in chalcopyrite CIS thin films and these films have nanostructured morphology onto amorphous/nanocrystalline phase of CdS. The OVC–CIS films are p-type with a band gap energy of 1.453 eV.</P>

Morphology-Dependent Electrochemical Supercapacitor Properties of Indium Oxide

Chang, Jinho,Lee, Wonjoo,Mane, Rajaram S.,Cho, Byung Won,Han, Sung-Hwan The Electrochemical Society 2008 Electrochemical and solid-state letters Vol.11 No.1