Showing papers by "Somnath C. Roy published in 2020"
TL;DR: In this paper, the authors report the CuO/Cu2O nanoflake/nanowire heterostructure with the enhanced surface area directly grown on Cu foil through scalable process steps ensuring easy large-scale fabrication.
39 citations
TL;DR: In this article, a simple and scalable scheme for the functionalization of TiO2 nanotube with g-C3N4 to achieve enhanced photo-electrochemical properties has been proposed.
21 citations
TL;DR: In this article, the mechanism of NO2 interaction on semiconductor surfaces such as TiO2 is investigated and a key step in designing the catalytic processes for converting NO2 to useful products.
Abstract: Understanding the mechanism of NO2 interaction on semiconductor surfaces such as TiO2 is a key step in designing the catalytic processes for conversion of NO2 to useful products. In the present wor...
9 citations
TL;DR: The efficient generation of charge carriers under light irradiation and easy separation because of favourable band alignment are attributed to the high photoelectrochemical current density in these tricomponent photocatalyst system.
Abstract: Absorption of visible light and separation of photogenerated charges are two primary pathways to improve the photocurrent performance of semiconductor photoelectrodes. Here, we present a unique design of tricomponent photocatalyst comprising of TiO2 multileg nanotubes (MLNTs), reduced graphene oxide (rGO) and CdS nanoparticles. The tricomponent photocatalyst shows a significant red-shift in the optical absorption (∼2.2 eV) compared to that of bare TiO2 MLNTs (∼3.2 eV). The availability of both inner and outer surfaces areas of MLNTs, the visible light absorption of CdS, and charge separating behavior of reduced graphene oxide layers contribute coherently to yield a photocurrent density of ∼11 mA cm-2 @ 1 V vs. Ag/AgCl (100 mW cm-2, AM 1.5 G). Such a high PEC performance from TiO2/rGO/CdS photoelectrode system has been analyzed using diffused reflectance (DRS) and electrochemical impedance (EIS) spectroscopy techniques. The efficient generation of charge carriers under light irradiation and easy separation because of favourable band alignment, are attributed to the high photoelectrochemical current density in these tricomponent photocatalyst systems.
9 citations
TL;DR: In this article, the authors reported a nearly three times increase in the total photoluminescence emission of CQD films by depositing them on TiO2 nanotube (NT) substrates, instead of glass.
9 citations
TL;DR: The results suggest that Bismuth deposited by DC sputtering leads to well-defined BFO nanorods, which shows superior performance in both multiferroic and photoelectrochemical studies.
Abstract: BiFeO3 has been widely investigated in many forms and morphologies because of both multiferroic and photovoltaic properties. However, direct growth of vertically aligned BiFeO3 nanorods on an underlying substrate has remained a challenge. In this work, we report template free growth of vertically aligned BiFeO3 nanorods on Fluorine doped Tin Oxide (FTO) coated glass substrate. This has been achieved by a two-step process, in which FeOOH nanorods are grown by chemical bath deposition and converted into BiFeO3 using Bismuth (Bi) coating by physical vapour deposition (PVD). Both DC sputtering and thermal evaporation are attempted under PVD and the results suggest that Bismuth deposited by DC sputtering leads to well-defined BFO nanorods, which shows superior performance in both multiferroic and photoelectrochemical studies. Piezoelectric force microscopy data shows the signature butterfly loop that confirms piezoelectric behaviour with a d33 value of 8 pmV-1 in the BFO nanorods grown by DC sputtering. Further, the M-H hysteresis curve for the same samples reveals remanent magnetization (Mr) value of 0.54 emu cc-1 and antiferromagnetic nature at room temperature. Finally, a stable photocurrent density of 0.05 mA cm-2 is achieved at 0.8 V vs Ag/AgCl under 1 Sun illumination. This work opens up new avenues for BiFeO3 in applications involving 1D nanostructures.
7 citations
TL;DR: This model highlights the benefits of consideration of two-layered coating and does predict underlying mechanism for better efficacy by tweaking the kinetics parameters.
Abstract: An attempt is made in the present investigation to develop a computational model for the purpose of studying the effect of interstitial flow in the porous media on the distribution of drug eluted f
6 citations
08 Dec 2020
TL;DR: In this article, the growth of stable TiO2 nanotube arrays on flexible Kapton substrates by electrochemical anodization of a sputtered Ti (titanium) film was reported.
Abstract: This work reports the growth of stable TiO2 nanotube arrays on flexible Kapton substrates by electrochemical anodization of a sputtered Ti (titanium) film. Although such nanotubes are conventionall...
3 citations
30 Dec 2020
1 citations
TL;DR: In this paper, both the velocity of the molten metal, surface heat extraction rate and also the mold shapes are taken into account in the numerical analysis of the continuous casting process of continuous casting.
Abstract: Thermal physics of continuous casting is strongly dependent on the velocity of the molten metal, surface heat extraction rate and also on the mold shapes. In the present numerical study, both the m...
1 citations
TL;DR: In this paper, a high-k dielectric oxide (Gd2O3)-semiconductor (Ge) interface was characterized at the atomic scale using complex-valued exit wave reconstructed from a set of focal series high-resolution transmission electron microscopy (HRTEM) images acquired without objective lens spherical aberration correction.
01 Jan 2020
TL;DR: In this chapter, a detailed discussion of a coupled MAC-SOLA solver, a simple yet effective and robust method to address the issues of improper mass conservation in IBM, is presented.
Abstract: A sharp interface immersed boundary method uses a local velocity reconstruction scheme to satisfy the boundary conditions over the complex/moving boundary. However, mass conservation is not physically ensured at the intercepted cells through this reconstruction schemes. Further, the solution can be marred with unphysical spurious oscillations in the temporal behavior of pressure when dealing with the moving boundary problems. In this chapter, a detailed discussion of a coupled MAC-SOLA solver, a simple yet effective and robust method to address the issues of improper mass conservation in IBM, is presented. Implementation of IBM to solve moving boundary problems and the acceleration and GPGPU optimization of solver using OpenACC are also discussed in detail. Further, studies on the accuracy and computational efficiency are presented.