Diffuse Reflectance Spectrometer Research Articles

Assessment of acoustic shock wave resistance of SiO2 (α-cristobalite): A potential material for aerospace and defense industry applications

In the present research article, the acoustic shock wave-resistant efficiency of silica microparticles (SiO2-α-cristobalite)) has been experimentally evaluated in terms of structural, optical and morphological stability against the impact of shock waves. The required SiO2 particles were synthesized by a hydrothermal method which was subjected to a different number of shock pulses such as 200,400 and 600 with Mach number 2.2. Shocked samples’ structural, morphological and optical stabilities have been evaluated by utilizing a powder X-ray diffractometer (PXRD), Ultraviolet–Diffuse reflectance spectrometer (DRS) while the surface morphological analysis has been scrutinized by the field emission scanning electron microscopic technique (FESEM) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy techniques are utilized to evaluate oxidation states and crystallographic structural stability. The above-mentioned analytical techniques provide convincing proofs whereby the synthesized SiO2 particles are authentically proven to possess outstanding structural, optical and morphological stability against the impact of shock waves. The implicated experimental results and the arguments strongly suggest that the SiO2 particles are suitable candidates for aerospace and defense industry applications due to their outstanding shock wave-resistant properties.

Efficient chlorination reaction of Pt/RuO2/g-C3N4 under visible light irradiation for simultaneous removal of ammonia and bacteria from mariculture wastewater

The removal of ammonia nitrogen (NH4+-N) and bacteria from aquaculture wastewater holds paramount ecological and production significance. In this study, Pt/RuO2/g-C3N4 photocatalysts were prepared by depositing Pt and RuO2 particles onto g-C3N4. The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV–vis diffuse reflectance spectrometer (UV–vis DRS). The photocatalysts were then applied to the removal of both NH4+-N and bacteria from simulated mariculture wastewater. The results clarified that the removals of both NH4+-N and bacteria were in the sequence of g-C3N4 < RuO2/g-C3N4 < Pt/g-C3N4 < Pt/RuO2/g-C3N4. This magnificent photocatalytic ability of Pt/RuO2/g-C3N4 can be interpreted by the transfer of holes from g-C3N4 to RuO2 to facilitate the in situ generation of HClO from Cl− in wastewater, while Pt extracts photogenerated electrons for H2 formation to enhance the reaction. The removal of NH4+-N and disinfection effect were more pronounced in simulated seawater than in pure water. The removal efficiency of NH4+-N increases with an increase in pH of wastewater, while the bactericidal effect was more significant under a lower pH in a pH range of 6–9. In actual seawater aquaculture wastewater, Pt/RuO2/g-C3N4 still exhibits effective removal efficiency of NH4+-N and bactericidal performance under sunlight. This study provides an alternative avenue for removement of NH4+-N and bacteria from saline waters under sunlight.

Sago-shaped embedded Nanolayers of WO3/NiO/gC3N4 Nanohybrids for natural degradation of environmental pollutants: A photocatalytic sunlight mediated approach

In recent years the applicability of semiconductor nanomaterials is almost in every field of science and technology. In the current study, hybrid nanomaterials containing tungsten trioxide (WO3) and nickel oxide (NiO) supported on graphitic carbon nitride (gC3N4) were prepared by a simple hydrothermal technique. Synthesis was sequential requiring the individual preparation of gC3N4 and WO3 as preliminary. The desired composition of gC3N4, WO3, nickel nitrate, and a base was transferred to an autoclave and maintained at 180°C for 18 h. The resulting inorganic/organic hybrid was filtered, washed, dried, and named as inorganic/organic hybrid nanocomposite (HNC). Various compositions of HNC were prepared and characterized by Fourier transform infrared spectrometer (FT-IR), Ultra Violet-Visible Diffuse reflectance spectrometer (UV–Vis-DRS), X-ray diffractometer (XRD), and Field emission scanning electron microscope (FE-SEM). The FE-SEM images showed a sago-shaped embedded particle in gC3N4 layers with a 40–60 nm particle size. The band gap energy was found to be 2.69 eV from UV–Vis-DRS analysis. This proves the promising activity of sago-shaped HNC under sunlight radiation. Various preliminary and kinetic studies were conducted, and HNC possessed excellent photocatalytic activity for the degradation of an organic dye under sunlight. The photocatalytic activity for the degradation of dye by the prepared HNC was found to be two-fold when compared to the activity of pristine gC3N4 under sunlight irradiation.

MoS2 modified g-C3N4 composite: A potential candidate for photocatalytic applications

A potential photocatalytic activity of MoS2-modified g-C3N4 composite for methylene blue (MB) dye degradation is processed under sunlight radiation. The photocatalyst materials (g-C3N4, MoS2, and g-C3N4/MoS2) were prepared by low-temperature hydrothermal method and the synthesized samples were further characterized through the X-ray diffraction (XRD), UV–vis diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) and Photoluminescence (PL) spectroscopy techniques. Initially, the formation of the crystalline structure of (g-C3N4, MoS2, and g-C3N4/MoS2) samples was identified through the XRD technique. Further, the morphology of the MoS2-modified g-C3N4 when observed through SEM was found to be a regular structure with minute pores and voids when compared to the other two samples resulting in better light absorption capacity. The elemental composition of synthesized composite is analyzed by XPS spectra. The energy band gap investigated through the DRS spectra was 2.9 eV, 1.8 eV and 1.82 eV for the g-C3N4, MoS2, and g-C3N4/MoS2 samples respectively. Further BET, TOC and scavenger radical analysis was conducted on the tested sample to analyze the degradation process. Thus, the composite photocatalyst material of MoS2-modified g-C3N4 has an enhanced recombination electron-hole pair rate. Finally, the photocatalytic feature of the composite (g-C3N4/MoS2) tested on MB dye solution under sunlight irradiation for 2 hr was found to be successful.

Photocatalytic degradation of naphthol blue from Batik wastewater using functionalized TiO2-based composites

This work provides a first-time comparative study examining the photocatalytic activity of functionalized TiO2-based composites to eliminate naphthol blue in Batik wastewater. Reduced graphene oxide (RGO) was synthesized by oxidizing solid graphite using the Hummers' method followed by sonication and reduction. N-doped TiO2 (N–TiO2) was synthesized from titanium tetrachloride (TiCl4) and urea (CH₄N₂O) precursors by the sol-gel method. N–TiO2 modified RGO (RGO/NT) was synthesized using a hydrothermal method from N–TiO2 and RGO. Prepared TiO2-based composites and commercial TiO2, for comparison were characterized using Fourier transform infrared spectrometer (FTIR), X-Ray diffractometer (XRD), scanning electron microscope-energy dispersive X-ray (SEM-EDX), and UV–Vis diffuse reflectance spectrometer (UV–Vis DRS). FTIR characterization indicated Ti–N bonding in N–TiO2 and RGO/NT. XRD patterns showed that commercial TiO2 had a rutile phase, while N–TiO2 and RGO/NT had an anatase phase with crystal sizes of 30.09, 16.28, and 12.02 nm, respectively. SEM results displayed the presence of small and glossy white N–TiO2 dispersed on the surface of RGO. Characterization using UV–Vis DRS showed that the band gap energy values for TiO2, N–TiO2, and RGO/NT were 3.25, 3.12, and 3.08 eV with absorption regions at the wavelengths of 382, 398, and 403 nm, respectively. The highest photocatalytic activity for RGO/NT for degrading naphthol blue was obtained at pH 5, with a photocatalyst mass of 60 mg, and an irradiation of 15 min. Photocatalytic degradation by RGO/NT on Batik wastewater under visible light showed higher effectivity than under UV light.

Mechanism insights into the enhanced photocatatlytic peroxydisulfate activation by Fe3O4/BiOI heterojunction

Combining various advanced oxidation processes has been considered as an emerging approach for degrading organic contaminants, which can overcome the deficiencies of a single one. In this study, the photocatalytic oxidation and persulfate-based oxidation were allied for degrading high-concentration Rhodamine B (RhB). To strengthen this alliance, Fe3O4/BiOI p-n heterojunctions were constructed by anchoring Fe3O4 nanoparticles onto flower-like BiOI. Various instrumental techniques, including X-ray diffractometer, field emission scanning electron microscope, transmission electron microscope, X-ray photoelectron spectrometer, photoluminescence emission spectroscopy, UV–Vis diffuse reflectance spectrometer, vibrating sample magnetometer and surface area analyzer were used to characterize these heterojunctions. 100 mg·L−1 RhB was utilized as the probing target to appraise the photocatalytic peroxydisulfate activation by Fe3O4/BiOI heterojunction under visible light illumination. The pseudo-first-order kinetic model could well describe the RhB degradation process. Finally, the mechanism on the photocatalytic peroxydisulfate activation over Fe3O4/BiOI heterojunction was proposed and discussed.

A TiO2/Si carrier derived from photovoltaic solid waste to assemble Ag3PO4/Co3(PO4)2/TiO2/Si heterostructure for enhancing visible-light photocatalytic activity

The rapid development of the photovoltaic solar industry has generated a huge amount of retired waste silicon panels. The management and value-added recycling of silicon wafer waste are highly important for both environmental remediation and economic efficiency. In this work, waste solar silicon wafers were ball-milled to obtain silicon powder that was employed to prepare TiO2/Si by hydrothermal synthesis, which then was converted to support Ag3PO4 and Co3(PO4)2 with a co-precipitation method to yield Ag3PO4/Co3(PO4)2/TiO2/Si (APO/CPO/TIO/Si) composite catalyst. The photocatalytic properties of the materials doped with different concentrations of APO or CPO were examined using methyl orange (MO) degradation rate as a performance metric. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectrometer (DRS), and ultraviolet-visible spectrophotometer (UV–vis) were used to characterize and analyze the morphology, grain size, material phase, and photocatalytic performance of the samples, respectively. Furthermore, the mechanism derived for the APO/CPO/TIO/Si catalyst in the photocatalytic degradation revealed that superoxide radical (•O2-), singlet oxygen (1O2), and hydroxyl radical (•OH) are the major active substances during the photocatalytic process, the enhanced photocatalytic activity contributing to a heterojunction electron transfer pathway. This work provides a promising approach for waste solar panels management as well as a high-performance photocatalyst for environmental decontamination.

Noble metal-doped TiO2 thin films in the efficient removal of Mordant Orange-1: insights of degradation process.

Nanocomposite Ag0(NPs)/TiO2 is synthesised in a facile template method enabling nanoparticles of reduced Ag evenly distributed within the titania network. The morphological studies of nanocomposites were extensively performed employing SEM/EDX (scanning electron microscopy/energy dispersive X-ray), TEM (transmission electron microscopy) and AFM (atomic force microscopy). Moreover, the bandgap energies of materials were obtained using the diffuse reflectance spectrometer (DRS). The newer insights in the photocatalytic elimination of Mordant Orange-1 (MO1) was obtained using the nanocomposite thin film for various parametric studies utilising the UV-A and LED illuminations. The kinetics of degradation of MO1 was performed, and the rate constant was favoured at lower concentrations of MO1. Moreover, the elimination efficiency of MO1 was favoured with a decrease in solution pH. The NPOC results inferred that a fairly good extent of MO1 was mineralised using a thin-film catalyst for both the UV-A and LED illuminations. The minimal effect of several co-ions demonstrated the applicability of thin films in the elimination of MO1, and the stability of the thin film has shown the potential applicability of thin-film catalysts. Further, the mechanism of photocatalytic degradation was demonstrated with the radical scavenger studies and ascertained the reaction pathways.

Influence of data pre-processing techniques for PLSR model to predict blood glucose by NIR spectroscopy

NIR diffuse reflectance spectroscopic spectra can be mathematically modelled to extract quantitative information by suitable multivariate calibration models. The analysis of spectral data becomes complex as the data is more prone to noise due to light scattering and baseline effects. These errors reduces the robustness and reliability of the developed calibration model. Hence data pre-processing becomes the most important aspect in data analysis. Different mathematical transformations are applied to remove the noise present in the data. This work focuses on the various empirical data pre-processing techniques like baseline correction, multiplicative scatter correction (MSC), robust MSC, extended multiplicative signal correction (EMSC), orthogonal signal correction (OSC) and (-log R) followed by standard normal variate (SNV) techniques for Partial Least Square Regression (PLSR) model in the prediction of blood glucose non-invasively. The performance of the PLSR model for the acquired (raw) spectral data and the same data subjected to different pre-processing techniques is analyzed. The model complexity and robustness is evaluated in terms of the number of latent variables (LVs) required to build the calibration model and obtained mean square prediction error after cross validation. This study utilizes the spectral data collected from 207 subjects from a diabetic center using Diffuse Reflectance Spectrometer (DRS). The analyzed results show that pre-processing based on (-log R) followed by SNV is found to perform well with reduced model complexity and minimum estimated mean square prediction error of 0.23 mg/dl among the other empirical pre-processing techniques. Keywords: multiplicative scatter correction (MSC), orthogonal signal correction (OSC), standard normal variate (SNV), Diffuse Reflectance Spectrometer (DRS).

Influence of data pre-processing techniques for plsr model to predict blood glucose by nir spectroscopy-=SUP=-*-=/SUP=-

NIR diffuse reflectance spectroscopic spectra can be mathematically modelled to extract quantitative information by suitable multivariate calibration models. The analysis of spectral data becomes complex as the data is more prone to noise due to light scattering and baseline effects. These errors reduces the robustness and reliability of the developed calibration model. Hence data pre-processing becomes the most important aspect in data analysis. Different mathematical transformations are applied to remove the noise present in the data. This work focuses on the various empirical data pre-processing techniques like baseline correction, multiplicative scatter correction (MSC), robust MSC, extended multiplicative signal correction (EMSC), orthogonal signal correction (OSC) and (-log R) followed by standard normal variate (SNV) techniques for Partial Least Square Regression (PLSR) model in the prediction of blood glucose non-invasively. The performance of the PLSR model for the acquired (raw) spectral data and the same data subjected to different pre-processing techniques is analyzed. The model complexity and robustness is evaluated in terms of the number of latent variables (LVs) required to build the calibration model and obtained mean square prediction error after cross validation. This study utilizes the spectral data collected from 207 subjects from a diabetic center using Diffuse Reflectance Spectrometer (DRS). The analyzed results show that pre-processing based on (-log R) followed by SNV is found to perform well with reduced model complexity and minimum estimated mean square prediction error of 0.23 mg/dl among the other empirical pre-processing techniques. Keywords:

Methylene Blue Dye Photodegradation during Synthesis and Characterization of WO3 Nanoparticles

Semiconductor-based photocatalytic systems have found widespread use in environmental pollution cleanup and renewable energy production. In this study, we synthesized WO3 as a catalyst for the degradation of methylene blue, a thiazine dye, which was used in the previous work. The hydrothermal process is used to create WO3 nanoparticles, which are made from sodium tungstate. When it comes to confirming the nanoparticles, many characterization techniques are employed, including X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV-Vis diffuse reflectance spectrometer (DRS), X-ray photoelectron spectroscopy (XPS), and field emission–scanning electron microscope (FE-SEM). The existence of monoclinic crystalline structure is shown by XRD, with the average crystalline size being around 34 nm. FTIR confirms the presence of metal oxides. The pellucid absorption extremity in the UV-Vis region corresponds to the rudimentary absorption of the WO3 semiconductor. FE-SEM confirms square-shaped nanoplates with EDX address the occurrence of elemental tungsten. The photocatalytic activity of WO3 nanoparticles against methylene blue is taken for at different intervals of time that confirms MB’s degradation. Our present work suggests that prepared nanoparticles should be potential for photocatalysts using various industrial dyes.

Green synthesis of tin oxide nanoparticles by using leaves extract of Chromolaena Odorata: The effect of different thermal calcination temperature to the energy band gap

Tin oxide nanoparticles (SnO2 Nps) are critical conducting oxides that are used in numerous applications, inclusive of solar cells, electrodes, gas sensors, optoelectronic devices, and catalysts. The green production of SnO2 Nps utilising leaves extract of Chromalaena Odorata is described in this research. SnO2 Nps were synthesised at ambient temperature and then calcined at five different calcination temperatures, which were 500, 600, 700, 800, and 900 °C, with slow and in-situ thermal calcination modes. The X-Ray Diffraction (XRD), Fourier-Transform Infrared (FTIR), Field-Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDX), and UV–Vis Diffuse Reflectance Spectrometer were utilised to analyse all the resulting outcomes. The Kubelka-Munk (KM) function calculated the SnO2 Nps energy characteristic. From this study, the main findings can be divided into 2 parts. First, at slow thermal calcination mode, SnO2 Nps exhibit the highest energy band gap value (3.2 eV) at 900 °C with a reflectance of 53%. Second, at in-situ thermal calcination mode, SnO2 Nps exhibit the highest energy band gap value (3.3 eV) at 800 °C with a reflectance of 49%. Overall, the results suggest that the green synthesised SnO2 Nps can hold as a promising candidate for optical application.

Exploration of structural, thermal stability and band-gap tunability of organic and inorganic mixed cation (MA)1−x Cs x PbBr3 perovskite harvester via ultrasonication synthesis route

Extensive investigation over the last few years has been done on halide based perovskite light harvester due to higher power conversion efficiency but the thermal stability with organic cation i.e. methylamine is challenging for the commercialization. Therefore, for improved structural and thermal stability, it is significant to develop a mixed cation base perovskite compound. To improve the thermal and structural stability of the material and easy synthesis method for industrialization of the material, we have demonstrated the compositional engineering of MA/CsPbBr3 perovskite material via ultrasonication synthesis process. The x-ray diffraction, transmission electron microscope, diffuse reflectance spectrometer and simultaneous thermal analyzer (STA) analysis were performed in order to understand the impact of the Cs+ into MAPbBr3 perovskite structure. Structural study reveals that up to 40% Cs+ incorporation into MAPbBr3 has pure Pm−3m cubic phase of perovskite compound with continuously increase in micro strain and lattice contraction. On the other hand, with increasing the concentration of Cs+ than MA+, optical band gap slightly increases. The thermodynamic behavior and thermal stability of the sample was studied with STA (differential scanning calorimetry/thermogravimetry). For the new generation optoelectronics with admirable stability, we believe that pure phase MA0.60Cs0.40PbBr3 perovskite compound may be a promising candidate.

Effect of Sb doping on the photocatalytic performance of Z-scheme TiO2NRA/SnO2/potassium titanate heterojunction and its photocatalytic mechanism

Firstly, Sb–SnO2/potassium titanate (Sb–SnO2/K4TiO4 (KTO)) was fabricated by a sol-gel method, and then TiO2 nanorod arrays were grown on the surface of Sb–SnO2/KTO by a hydrothermal method (TiO2NRA/Sb–SnO2/KTO). The photocatalytic activity was evaluated by degrading tetracycline hydrochloride (TCH). The prepared samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), ultraviolet–visible diffuse reflectance spectrometer (UV–Vis), and X-ray photoelectron spectroscopic characterizations (XPS). The results show that the Z-scheme heterojunction formed between SnO2/KTO and TiO2 can enhance the range of light response. With the doping of Sb, the conductivity of the composite is enhanced, which is advantageous to the transfer of electron and the low recombination rate of electron-hole pairs. Thus, the doping of Sb is effective to improve the photocatalytic performance. Our work demonstrates the optimal doping amount of Sb is 5%. The degradation efficiency of TCH concentration can reach 95.6% after 2 h and TiO2NRA/Sb–SnO2/KTO shows good reusability.

Photocatalytic degradation of malachite green dye using zero valent iron doped polypyrrole

The zero valent iron doped polypyrrole (Ppy/Fe) was synthesized via chemical oxidative polymerization method in diethylene glycol medium for the first time in this study. The characterization of synthesized Ppy and Ppy/Fe composites was realized by using fourier transform infrared spectrometer (FTIR), UV-visible diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), elemental dispersion X-ray analysis (EDX), four point probe electrical conductivity X-Ray diffraction spectroscopy (XRD) and pH at point of zero charge (pHpzc) methods. These characterizations show that there is an interaction between zero valent iron (Fe0) and Ppy polymer. The photocatalytic activity of synthesized Ppy and Ppy/Fe composite were investigated by degradation of malachite green (MG) dye under UV light irradiation. Ppy/Fe composite was achieved complete degradation within 60 min, which is 5.92 times faster than pure Ppy. The effect of irradiation time, ratio of Ppy and Fe0 in the synthesized composites, photocatalyst amount to photocatalytic efficiency of Ppy/Fe is studied. Also, the photocatalytic stability of Ppy/Fe is investigated under UV light illumination for degradation MG dye.

Microwave and Induction Heating-Assisted Biosynthesis of 12CaO 7Al2O3 Electride from Aloe Vera Leaf Extract

The white powders used as precursor powders for the synthesis of 12CaO×7Al2O3 electride (C12A7:e-) were prepared by biosynthesis method using Aloe vera extract and microwave assisted synthesis. The C12A7:e- crystals were synthesized by induction heating process under a reducing atmosphere at different times of 3, 4 and 5 min. The structure of C12A7:e- powders was characterized by X-ray diffraction. The XRD analysis revealed that pure C12A7:e- powders were obtained from white precursor powders with an induction heating process time of 5 min. To confirm that the white precursor powders were transformed into C12A7:e- after induction heating process for 3, 4 and 5 min, the optical absorption spectra of powders were investigated by an UV-Vis diffuse reflectance spectrometer in the wavelength range of 200 – 800 nm. The results show the optical absorption bands at 2.8 eV for the white precursor powders with induction heating time of 3, 4 and 5 min. This is due to the C12A7 was transformed into electride (C12A7:e-). Therefore, the results on the optical absorption spectra are in good agreement with the XRD results.

Photocatalytic reduction of CO2 into methanol over Cu–Ni–TiO2 supported on SiO2-Al2O3 catalyst

The photocatalytic reduction of carbon dioxide into hydrocarbon over bimetallic-loaded TiO2 supported on SiO2-Al2O3 (Ni–Cu–TiO2 /SiO2-Al2O3) catalyst was studied. The study also compared the performance of the catalyst with Degussa P25 (TiO2), prepared TiO2, SiO2-Al2O3 loaded with TiO2. The investigation of catalytic performance was carried out in a batch reactor under UV irradiation. All the samples were characterized by X-ray diffractometer (XRD), N2 gas adsorption–desorption, and Ultraviolet–visible diffuse reflectance spectrometer (UV–Vis-DRS). The result showed SiO2-Al2O3loaded with Ni–Cu–TiO2 yielded the highest production rate of methanol (405.08μmol/gcat ) after 2 h of reaction under UV at room temperature and a pressure of 1 atm. The photocatalytic reduction rate over the bimetallic-loaded TiO2 supported on SiO2-Al2O3 catalysts was found to be approximately 2.4 times that over SiO2-Al2O3 loaded with TiO2. This can be explained by the presence of nickel and copper on the catalyst which reduced the energy bandgap of the catalyst and decreased the recombination of electron–hole pairs.

Synthesis and characterization of TiO2 and palm oil fiber ash hybrid photocatalysts for seawater pretreatment

Titanium dioxide (TiO2) has been used in various applications such as air purification, water purification, and photoelectrochemical conversion systems. However, developing advanced materials with enhanced performance for catalytic applications, especially water treatment, is highly required. This work aims to study the effect of (TiO2) photocatalyst in pretreatment seawater desalination. The catalyst with a mass ratio of TiO2: palm oil fibre ash (POFA) at 0:100, 40:60, 60:40, and 100:0 was synthesized via wet impregnation. The catalyst was calcined at 500 ℃ for four hours. The mixture of artificial seawater and catalyst at a mass ratio of photocatalyst: artificial seawater at 1:300 was put in a one-litre borosilicate photo-reactor fixed with mercury light of 350 nm for two hours with stirring at 1000 rpm. In this investigation, an evaporator was used to collect the freshwater. The fresh and spent catalysts were characterized via X-Ray Diffractogram (XRD), Nitrogen physisorption analysis, Diffuse Reflectance Spectrometer (DRS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDX). The catalyst with Ti: palm oil fibre ash (POFA) at 40:60 and 60:40 can reduce the COD at 45 % and 41%, respectively. As more OPFA was added into the hybrid TiO2 catalyst, there has been a change in the properties of seawater due to the use of special evaporators, especially EC and TDS. It can be deduced that the hybrid TiO2 photocatalyst synthesized with OPFA has vast potential to treat seawater.

Investigation on structural and optical properties of CuO doped CdS-Zn3(PO4)2 nanocomposite for optoelectronic devices

Pure and CuO (0.3, 0.6 and 0.9 mol%) doped CdS-Zn3(PO4)2 semiconducting nanophosphors were synthesized by hydrothermal technique under mild reaction temperatures. The prepared samples were systematically investigated by Powder X-ray diffraction [XRD], Fourier Transform infra-red spectroscopy [FT-IR], Scanning electron microscopy [SEM] with EDAX, UV–Vis diffuse reflectance spectrometer [DRS] and Photoluminescence [PL] techniques. X-ray diffraction pattern shows hexagonal phase of CdS and monoclinic β-phase of Zn3(PO4)2 with good crystalline nature. The average crystallite size of nanocomposites are in the range 13 to 25 nm and found to decrease from 18 nm to 13 nm with increasing dopant concentration. FT-IR spectra indicate that the prepared samples are high in purity. The surface morphology of the samples has shown a hetero structure type morphology in which hexagonal CdS spheres network bonding accumulated on rectangular flakes. The obtained chemical composition of all the samples are identified by EDAX is in agreement with the calculated stoichiometry. The optical band gap values are determined by diffuse reflectance spectra and are found to be in the range 2.49 eV to 2.39 eV. The room temperature Photoluminescence spectra of pure CdS-Zn3(PO4)2 lattice shown a broad strong green emission peak at ~ 518 nm, while upon incorporation CuO ions in host lattice, a sharp luminescence peak around 393 nm has been observed in all the doped samples along with other peaks at 494 nm, 594 nm, 684 nm which are in the violet, blue-green-red fluorescence of UV-Visible region makes them suitable for optoelectronic device applications.

A Sm-doped Egeria-densa-like ZnO nanowires@PVDF nanofiber membrane for high-efficiency water clean

A biomimetic Egeria-densa-like hybrid composite nanofiber membrane was fabricated to degrade organic pollutants in water, with PVDF nanofibers as stems to provide support, and ZnO nanowires as leaves to provide active sites. The Sm-doped ZnO nanowires@PVDF nanofiber membranes were characterized by FE-SEM, X-ray photoelectron spectroscopy, Fourier transform infrared, X-ray diffraction, and UV–vis diffuse reflectance spectrometer. Compared with the pure ZnO nanowires@PVDF nanofiber membrane, the Sm-doped membrane showed higher photocatalytic performance. The excellent photocatalytic activity was attributed to the increased specific surface area and the decreased bandgap of ZnO nanowires after Sm doping, which inhibited the recombination rate of electrons and holes and improved the absorption of visible light. We found that the superoxide free radicals (O2−) played a critical role in photocatalytic degradation. The Sm-doped ZnO nanowires@PVDF nanofiber membrane exhibited good stability after 5 cycles of RhB degradation. We believe such Sm-doped hybrid membrane can work as an effective photocatalyst for wastewater treatment.