Joint structure-modification strategies can effectively enhance photocatalytic activity of polymeric carbon nitride (PCN), but there still lack the carbon/defect comodification means, let alone research on its application in synchronous H2 evolution and contaminant degradation. Herein, a dual strategy was used to successfully synthesize carbon/defect (nitrogen vacancy) comodified PCN (cd-PCN) porous nanotubes with increased surface area and enhanced photoabsorption, charge separation, and photocatalytic H2 evolution. Benefiting from synergism of introduced carbon and defects, cd-PCN exhibits a ∼84 times higher H2 evolution rate (∼9.1 μmol h−1) than PCN with synchronous bisphenol A degradation by direct hole oxidation and a ∼13-fold higher H2 evolution rate (1704 μmol h−1) with triethanolamine as the electron donor under visible light irradiation. This work provides an efficient photocatalyst for simultaneous photocatalytic water splitting and contaminant degradation and expounds the significance of joint strategies in structure modification of PCN photocatalysts.

A dual strategy for synthesizing carbon/defect comodified polymeric carbon nitride porous nanotubes with boosted photocatalytic hydrogen evolution and synchronous contaminant degradation

MoSe2 is a 2D layered transition metal dichalcogenide that has attracted much attention because its properties may be easily altered by both morphology control and doping by substitutional transition metals. Here, the study of Ru-doped MoSe2 nanoflowers is presented, and the effect of Ru doping on their optical, electronic, and catalytic properties is presented. A significant enhancement in their catalytic properties toward the hydrogen evolution reaction (HER) is evident, showing an overpotential as low as 143 mV (at 10 mA cm–2) for samples by substituting 11.4% of the Mo with Ru. In order to gain understanding of the dopants’ interaction with the host and the nature of the atomic-scale substrate for the catalytic reaction, density functional theory (DFT) calculations are employed to trace the modulation of the density of states (DOS) near the Fermi level and to model possible dopant sites. The Ru dopants have two additional d electrons and a high DOS near the Fermi level. The optical absorption spectra ...

Effect of Ru Doping on the Properties of MoSe2 Nanoflowers

Bipolar resistive switching and memristive properties of hydrothermally synthesized TiO2 nanorod array: Effect of growth temperature

We have successfully synthesized cadmium sulfoselenide (Cd(S1−xSex)) thin films via a simplistic and promising self-organized chemical growth process for photoelectrochemical (PEC) application. The effects of bath composition on the optical, structural, morphological, and electrical properties and the photoelectrochemical performance of (Cd(S1−xSex)) thin films have been investigated. Deposited thin films were characterized using UV-Vis spectrophotometry, X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) with a selected area electron diffraction (SAED) pattern, field-emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), electrical conductivity (EC) and thermoelectric power (TEP) measurement techniques. An optical absorption study showed that the maximum light absorption in the 630–720 nm wavelength range and the linear nature of absorption plots indicate that the transition is a direct allowed type. The optical band gap energy decreased from 2.13 to 1.71 eV with varying bath composition. The XRD study illustrated that deposited thin films are in the pure phase with a nanocrystalline nature. HRTEM images highlight the formation of clearly-defined, interconnected particle, which aggregated to form a well-grown custard apple-like morphology over the entire substrate and are in good accordance with FESEM micrographs. The SAED pattern shows a ring pattern indicating the nanocrystalline nature of the deposited thin film. The FESEM study demonstrated that the developed surface morphology is favorable for effectual light absorption in the solar spectrum. The XPS analysis specified the presence of Cd2+, S2− and Se2− elements in the deposited thin film. The EDS spectrum confirmed that thin film deposition occurs in a stoichiometric manner. From the EC measurement study, it was observed that electrical conductivity increases correspondingly for all thin films, indicating semiconducting behavior. TEP measurements established that Cd(S1−xSex) thin films are n-type in nature. Finally, the deposited thin films were tested for photoelectrochemical (PEC) application. The PEC study illustrated that (Cd(S0.2Se0.8)) thin film showed the highest power conversion efficiency (η) of 1.02% among reported values.

Simplistic construction of cadmium sulfoselenide thin films via a hybrid chemical process for enhanced photoelectrochemical performance

Tin-doped In2S3 films were grown by the chemical spray pyrolysis method using compressed air as a carrier gas. Tin is incorporated in the solution using SnCl4. Structural and optical properties of films were investigated by x-ray diffraction (XRD), absorption, Raman and photoluminescence spectroscopies. Field emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectroscopy were used to explore the surface morphology. The properties of In2S3 thin films are influenced by Sn doping. XRD studies revealed that the deposited films were polycrystalline in nature exhibiting cubic structure and oriented preferentially towards (111). According to FESEM, the surface morphology of the films was free of defects. Raman studies showed different peaks related to In2S3 phase and did not show any secondary phases of In-Sn and Sn-S. In2S3:Sn films exhibited transparency over 60–85% in the visible and infrared regions. The optical band gap was found to vary in the range 2.71–2.58 eV for direct transitions. The room temperature photoluminescence (PL) studies revealed two PL bands, centered at 529 nm (band A) and 725 nm (band B). From these results, one can conclude that our material can be used as transmittive windows in low-cost solar cells. The conductance and capacitance characterization at ambient temperature were also investigated and gave interesting physical properties for photovoltaic applications.

Study of Optical and Electrical Properties of In 2 S 3 :Sn Films Deposited by Spray Pyrolysis

Nanocrystalline MoBi2Se5 Ternary Mixed Metal Chalcogenide Thin-films for Solar Cell Applications

In the present investigation, we report facile hydrothermal synthesis of TiO2 nanorods with high density rutile phase on Transparent Conducting Oxide (TCO) for enhanced solar cell application. The structural, optical, morphological, compositional and electrochemical properties are investigated by detailed XRD, UV-Vis-NIR spectrophotometer, FESEM, TEM, EDAX, XPS and photoelectrochemical studies. It is demonstrated that, the deposited TiO2 thin film shows pure rutile phase with tetragonal crystal structure. Optical spectra showed strong light absorption in UV region and FESEM images confirm the time dependent growth of TiO2 nanorods. EDAX and XPS Spectra confirm the formation of pure TiO2 nanorods. Photoelectrochemical performance with respect to time dependent growth of TiO2 nanorods showed highest photoconversion efficiency E³ = 5.1%

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Time Dependent Facile Hydrothermal Synthesis of TiO2 Nanorods andtheir Photoelectrochemical Applications

Molybdenum Heteropolyoxometalate Thin Films for Solar Cell Applications

Summary
Polyaniline (PANI) thin films were successfully deposited using controlled electrodeposition (ED) technique from a mixed solution of 0.1M aniline and 0.5M H2SO4 on ITO coated substrate. The effect of different deposition cycles 10, 25, 50, 75, 100 on thickness, optical and morphological properties of electrodeposited PANI thin films was studied. The formation mechanism of highly conducting form of polyaniline i.e. Emeraldine salt is explained. The support of Fourier transform-infra red (FT-IR) and Raman spectroscopy was given to confirm Emeraldine salt of PANI. Further DC electrical conductivity of PANI has been measured in temperature range from 300 to 500 K using two point probe method. The optical and morphological properties of PANI give its application towards flexible electrochromic glasses.

V.B. Ghanwat

Papers

Nanocrystalline MoBi2Se5 Ternary Mixed Metal Chalcogenide Thin-films for Solar Cell Applications

Time Dependent Facile Hydrothermal Synthesis of TiO2 Nanorods andtheir Photoelectrochemical Applications

Molybdenum Heteropolyoxometalate Thin Films for Solar Cell Applications

Controlled Electrochemical Polymerization Strategies for Electroactive Polyaniline Thin Films

Photoelectrochemical Performance of MoBiInSe5 Mixed Metal Chalcogenide Thin Films