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Toulik Maitra

Bio: Toulik Maitra is an academic researcher from University of Calcutta. The author has contributed to research in topics: Heterojunction & Auxiliary electrode. The author has an hindex of 2, co-authored 6 publications receiving 9 citations.

Papers
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TL;DR: In this article, the authors reported the application of highly textured photon trapping infrared active vanadium sulphide nanowalls sensitized with visible active CdS nanoparticles supported on ultraviolet (UV) active TiO2 nanorods to obtain a wide range of light absorbance throughout the solar spectrum.
Abstract: Vanadium sulphide is an emerging infrared active photocatalyst that has not been utilized to its maximum potential. Herein, we report the application of highly textured photon trapping infrared active vanadium sulphide nanowalls sensitized with visible active CdS nanoparticles supported on ultraviolet (UV) active TiO2 nanorods to obtain a wide range of light absorbance throughout the solar spectrum for maximum solar energy utilization. The vanadium sulphide nanowall/TiO2 nanorod heterostructures were fabricated by a two-step hydrothermal approach followed by CdS sensitization by a successive ionic layer adsorption reaction (SILAR) process. Photoelectrochemical performance was analyzed using simulated solar irradiation (AM 1.5G, 100 mW cm−2) with potential linear sweep voltammetry. A maximum Applied Bias to Photocurrent Efficiency (ABPE) of 1.34% was observed at 0.58 V. It was interestingly noted that the photoanode performance decreased with an increase in CdS loading over 20 deposition cycles. The IPCE response of this photoanode confirmed high photoelectrochemical responses throughout the solar spectrum. Electrochemical impedance spectroscopy (EIS) and Mott–Schottky (MS) plots were used to analyze the charge transport process and electrode kinetics of the fabricated photoanodes. Stability analysis was carried out using chronoamperometry. DFT calculations and ray-tracing simulations were carried out to study the nanotexture effect on light absorption, band alignment, charge transfer pathways, and overall intricate electronic properties of the heterostructure. The nanostructure and crystal morphology were analyzed using different characterization tools. Our result represents the importance of fabrication of semiconductor heterostructures with high light absorption capabilities and efficient charge transport resulting from optimum band alignment, heterostructure designing and preferentially tailored nanotextured morphology.

17 citations

Journal ArticleDOI
TL;DR: In this article, a photoanode comprised of CdS sensitized CoFe2O4@Fe 2O3 hierarchical nanosphere arrays on a FTO glass substrate and its application in photoelectrochemical water splitting was demonstrated.
Abstract: The design of efficient heterojunction photoanodes with appropriate band alignment and ease of charge separation has been one of the most highly focused research areas in photoelectrodes. This work demonstrates the fabrication of a photoanode comprised of CdS sensitized CoFe2O4@Fe2O3 hierarchical nanosphere arrays on a FTO glass substrate and its application in photoelectrochemical water splitting. The hierarchical hematite nanosphere arrays were grown on FTO substrates by a solvothermal approach. Impregnation of Co2+ was achieved by surfactant-assisted low-temperature solvothermal phase transformation and a dipping process followed by annealing to form a CoFe2O4@Fe2O3 heterojunction. The effect of pre-annealing of substrates before the second hydrothermal step on Co2+ impregnation was studied along with the choice of the solvent. The fabricated electrodes were further sensitized with CdS nanoplate-like structures by a hydrothermal method to form a Z-scheme-Type II ternary heterojunction. The photoelectrochemical properties of the electrodes were analysed by potential linear sweep voltammetry under simulated solar irradiation (AM 1.5G, 100 mW cm−2) with a 0.5 M Na2S and 0.5 M Na2SO3 electrolyte. The highest ABPE% observed at 0.59 V (vs Ag/AgCl) was 0.86% for the photoanode comprised of CdS sensitized porous nanosphere arrays formed by solvothermal Co2+ impregnation along with pre-annealing. The fabricated electrodes showed low sheet and charge transfer resistance as observed from the EIS plot. The nanostructure morphology, crystal structure, and phase analysis were carried out using XRD, TEM, SEM and FESEM with EDAX. DFT calculations were carried out to unravel the underlying electronic structure and electron transport processes at the heterostructure interfaces. We hope to inspire more research on ordered heterostructures with superior charge transport properties, proper band alignment, enhanced light absorbance, and charge separation with this work. We also aim to focus on the effect of pre-annealing and solvent–surfactant pair selection on ion impregnation induced phase transformation in nanostructures.

13 citations

Journal ArticleDOI
TL;DR: In this paper, a solution-processed thin-film nickel doped molybdenum oxide counter electrode was proposed as a cheap alternative of platinum counter electrodes for Dye-Sensitized solar cells.

9 citations

Journal ArticleDOI
Abstract: Design of composite semiconductor nanostructures with proper band alignment for efficient charge separation and carrier transport has been at the center of research for photoelectrochemical water splitting. This work demonstrates the deposition of a NiFe2O4 @Fe2O3 core-shell nanostructured film sensitized with CdS to form a ternary heterojunction for cascade type electron transfer. The hematite nanostructures were grown by hydrothermal approach through dipping into a solution of Nickel Nitrate yielded anchoring of Ni2+ ions on the outer surface. The films were then annealed at 650 °C for the diffusion of Ni2+ ions into the hematite lattice which forms core-shell NiFe2O4 @Fe2O3 heterojunction. The films were further sensitized with CdS nanoparticles deposited by a hydrothermal approach to form the final ternary heterojunction photoanode. Several different nanostructures were grown and the effect of crystal facet tailoring was observed on Ni loading and photoelectrochemical performance. The photoelectrochemical measurements were carried out using a potentiostat under 100 mW/cm2 light source (150W Xenon Lamp) with Pt counter electrode and 0.5 M Na2S and 0.5 M Na2SO3 electrolyte. A current density of 3.47 mA/cm2 was observed at 1.23 V (vs Ag/AgCl). An Applied Bias to Photocurrent Efficiency (ABPE) of 1.8 % photoconversion efficiency was observed using the fabricated electrodes at 0.288V (vs Ag/AgCl).

1 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, a comprehensive report has been presented on the recent developments of CdS and its hybrid with focus on photo and electrocatalytic applications, including low cost and green water splitting for H2 generation, wastewater treatment by degradation of organics toxins e.g., Cr (VI), Rhodamine B, Methylene blue (MB), Methyl orange etc.

26 citations

Journal ArticleDOI
TL;DR: In this paper , a two-dimensional (2D) MoS2/MoSe2 heterostructure was used for photoelectrochemical hydrogen evolution reaction (HER) catalytic activity.

20 citations

Journal ArticleDOI
TL;DR: In this article , the mechanism underlying facet junction-dependent photocharge separation in polyhedral Cu2O is demonstrated, which is beneficial for understanding why 50-faceted C2O exhibiting quaternary facet junction possesses an enhanced photodegradation activity toward tetracycline.
Abstract: Uncovering the contribution of anisotropic crystal facets in single‐crystalline photocatalysts is still a challenge in fundamental study. Here, the mechanism underlying facet junction‐dependent photocharge separation in polyhedral Cu2O is demonstrated, which is beneficial for understanding why 50‐faceted Cu2O exhibiting quaternary {100}/{110}/{111}/{522} facet junction possesses an enhanced photodegradation activity toward tetracycline than that of the 26‐faceted Cu2O exhibiting ternary {100}/{110}/{111} and 18‐faceted Cu2O exhibiting binary {100}/{110} facet junction. Density functional theory (DFT) calculations and selective photodeposition results confirm that hierarchical facet junctions are formed in a 50‐faceted Cu2O, which could be regarded as one parallel connection between binary {110}/{111} and ternary {110}/{522}/{100} series facet junction for conduction band minimum, and another parallel connection between binary {100}/{522} and ternary {111}/{110}/{522} series facet junction for valence band maximum, leading to an unprecedented dual series‐parallel transfer pathway for more efficiently improved photocharge separation. Hopefully, this study would be a beneficial guideline for scientific researchers currently concentrating on the facet junction engineering of polyhedral photocatalysts.

16 citations

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TL;DR: In this article, the performance analysis of an organic dye-sensitized solar cell (DSSC), introducing MnO2 as an electron transport layer in TiO2/MnO2 bilayer assembly, was reported.
Abstract: This study reports the performance analysis of an organic dye-sensitized solar cell (DSSC), introducing MnO2 as an electron transport layer in TiO2/MnO2 bilayer assembly. The DSSCs have been fabricated using TiO2 and TiO2/MnO2 layer-by-layer architecture films onto fluorine-doped tin oxide (FTO) glass and sensitized with natural dye extracted from Malvaviscus penduliflorus flower in ethanol medium. The counter electrode was prepared to layer copper powder containing paste onto FTO's conductive side by the doctor's blade method. The optical, morphological, and structural properties of photoanodes were explored via ultraviolet–visible, field emission scanning electron microscopy, and X-ray diffraction analyses. Moreover, dye complexity and thermostability of dyes were characterized via Fourier-transform infrared spectroscopy and thermogravimetric analyses. The iodide/triiodide (i.e., I−/I3−) redox couple of electrolyte solution was employed as a charge transport medium between the electrodes. Finally, photoanode and counter electrode sandwiches were assembled to envisage the photovoltaic performance potential under simulated AM 1.5G solar illumination using 100 mW cm–2 light intensity. The as-fabricated DSSC comprising TiO2/MnO2 bilayer assembly exhibited 6.02 mA cm–2 short circuit current density (Jsc), 0.38 V open-circuit voltage (Voc), 40.38% fill factor, and 0.92% conversion efficiency, which is about 200% higher compared to the assembly devoid of MnO2 layer.

15 citations