scholarly journals Nanoporous TiN/TiO2/Alumina Membrane for Photoelectrochemical Hydrogen Production from Sewage Water

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2617
Author(s):  
Abdullah Almohammedi ◽  
Mohamed Shaban ◽  
Huda Mostafa ◽  
Mohamed Rabia

An aluminum oxide, Al2O3, template is prepared using a novel Ni imprinting method with high hexagonal pore accuracy and order. The pore diameter after the widening process is about 320 nm. TiO2 layer is deposited inside the template using atomic layer deposition (ALD) followed by the deposition of 6 nm TiN thin film over the TiO2 using a direct current (DC) sputtering unit. The prepared nanotubular TiN/TiO2/Al2O3 was fully characterized using different analytical tools such as X-ray diffraction (XRD), Energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), and optical UV-Vis spectroscopy. Exploring the current-voltage relationships under different light intensities, wavelengths, and temperatures was used to investigate the electrode’s application before and after Au coating for H2 production from sewage water splitting without the use of any sacrificing agents. All thermodynamic parameters were determined, as well as quantum efficiency (QE) and incident photon to current conversion efficiency (IPCE). The QE was 0.25% and 0.34% at 400 mW·cm−2 for the photoelectrode before and after Au coating, respectively. Also, the activation energy was 27.22 and 18.84 kJ·mol−1, the enthalpy was 24.26 and 15.77 J·mol−1, and the entropy was 238.1 and 211.5 kJ−1·mol−1 before and after Au coating, respectively. Because of its high stability and low cost, the prepared photoelectrode may be suitable for industrial applications.

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Trung Kien Pham ◽  
Tran Ngo Quan

In this paper, we report on synthesizing xonotlite, calcium silicate hydrate (CSH), via a hydrothermal reaction using rice husk from the Mekong Delta, Vietnam. The rice husks were burnt at 1000 °C for 3 h. Grey rice husk ash was collected, then mixed with Ca(OH)2 at a Ca/Si molar ratio of 1 : 1. This was followed by a hydrothermal reaction at 180 °C for 24 h and 48 h to obtain the xonotlite mineral. Before and after adsorption, 3-mm xonotlite pellets were thoroughly characterized using X-ray diffractometry (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy. This material has potential application in chromium(III) removal during a chrome-plating process. The adsorption efficiency of the 3-mm pellet samples reached more than 76 % after 12 h.


1999 ◽  
Vol 581 ◽  
Author(s):  
Q. Wei ◽  
C.M. Lieber

ABSTRACTA solution-based synthesis route was developed to produce large quantities of MgO nanorods. Hydrated basic magnesium chloride, which has needle-like crystal structure, was used as a precursor. A subsequent two-step transformation process with magnesium hydroxide as an intermediate product was used to preserve the morphology of the precursor to yield magnesium oxide nanorods. Scanning electron microscopy, powder X-ray diffraction and energy dispersive X-ray spectroscopy show that the products are very pure (>95%) crystalline MgO nanorods with diameters from 40 nm to 200 nm and lengths 10 microns or longer. High-resolution transmission electron microscopy and electron diffraction further reveal that these MgO nanorods are single crystals and that the rod axis is along the <110> crystal direction. A model for the structural transformation from hydrated basic magnesium chloride to magnesium oxide has been developed and compared to our experimental results. This solution-based process can be easily scaled-up, and is a low-cost source of pure magnesium oxide nanorods needed in many industrial applications, for example, as reinforcing agents in matrix composites and as flux-pinning centers in high-TC superconductors.


2013 ◽  
Vol 829 ◽  
pp. 902-906 ◽  
Author(s):  
Mohammad Derakhshani ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard

Recently photocatalytic materials have been used in variety of industrial applications. TiO2 is the only suitable photocatalytic material for industrial usage due to its benefits such as non-toxicity, stability, and low cost. TiO2 nanoparticles were successfully synthesized from titanium alkoxide precursor by sol-gel method. Effects of nitrogen doping on the microstructure and phase evolution of the TiO2 nanoparticles were investigated. The X-ray diffraction results of doped samples confirm the presence of anatase as the only crystalline phase. The addition of nitrogen in titania matrix leads to disappearance of rutile traces. The scanning electron microscopy show that TiO2 nanoparticle size decreases by increasing nitrogen doping. Furthermore, DSC-TG results reveal that the crystallization temperature of doped sample shifts to higher temperatures of about 100 °C.


2016 ◽  
Vol 75 (2) ◽  
pp. 439-450 ◽  
Author(s):  
Asmaa Ali ◽  
Abdelkader Ahmed ◽  
Ali Gad

This study aims to investigate the ability of low cost ceramic membrane filtration in removing three common heavy metals namely; Pb2+, Cu2+, and Cd2+ from water media. The work includes manufacturing ceramic membranes with dimensions of 15 by 15 cm and 2 cm thickness. The membranes were made from low cost materials of local clay mixed with different sawdust percentages of 0.5%, 2.0%, and 5.0%. The used clay was characterized by X-ray diffraction (XRD) and X-ray fluorescence analysis. Aqueous solutions of heavy metals were prepared in the laboratory and filtered through the ceramic membranes. The influence of the main parameters such as pH, initial driving pressure head, and concentration of heavy metals on their removal efficiency by ceramic membranes was investigated. Water samples were collected before and after the filtration process and their heavy metal concentrations were determined by chemical analysis. Moreover, a microstructural analysis using scanning electronic microscope (SEM) was performed on ceramic membranes before and after the filtration process. The chemical analysis results showed high removal efficiency up to 99% for the concerned heavy metals. SEM images approved these results by showing adsorbed metal ions on sides of the internal pores of the ceramic membranes.


Author(s):  
Ayan Mukherjee ◽  
Partha Mitra

In recent years, ternary cadmium zinc sulfide (CdZnS) alloy compounds have been paid much attention in the fields of opto-electronics, particularly in photovoltaic devices. CdZnS thin films can be prepared by different techniques among which chemical methods have more advantages. Among different chemical method, Chemical Bath Deposition (CBD) is simple, low cost and widely applicable in industrial applications. In this chapter, we have discussed different methods of preparation of CdZnS thin film and their obtained properties. Also, the films are characterized by XRD, TEM, FESEM, EDAX, UV-Vis spectroscopy, etc. The properties of CdZnS gives insight of the properties of ternary thin film semiconductor and it will help to design semiconductor with tuneable properties for future applications in optoelectronic sector.


Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2253 ◽  
Author(s):  
Magdalena Tuchowska ◽  
Barbara Muir ◽  
Mariola Kowalik ◽  
Robert P. Socha ◽  
Tomasz Bajda

Montmorillonite—the most popular mineral of the smectite group—has been recognized as a low-cost, easily available mineral sorbent of heavy metals and other organic and inorganic compounds that pollute water. The aim of this work was to determine the sorption mechanism and to identify the reaction products formed on the surface of montmorillonite and organo-montmorillonite after sorption of molybdates (Mo(VI)) and tungstates (W(VI)). Montmorillonites are often modified to generate a negative charge on the surface. The main objective of the study was to investigate and compare the features of Na-montmorillonite (Na-M), montmorillonite modified with dodecyl trimethyl ammonium bromide (DDTMA-M), and montmorillonite modified with didodecyl dimethyl ammonium bromide (DDDDMA-M) before and after sorption experiments. The material obtained after sorption was studied by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The XRD pattern showed the presence of a new crystallic phase in the sample that was observed under an SEM as an accumulation of crystals. The FTIR spectra showed bands related to Mo–O and W–O vibration (840 and 940 cm−1, respectively). The obtained results suggest that molybdenum(VI) and tungsten(VI) ions sorb onto the organo-montmorillonite in the form of alkylammonium molybdates and tungstates.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1767 ◽  
Author(s):  
Nasir Shezad ◽  
Ibrahim M. Maafa ◽  
Khairiraihanna Johari ◽  
Ainy Hafeez ◽  
Parveen Akhter ◽  
...  

Photocatalytic H2 production is a promising strategy toward green energy and alternative to carbon-based fuels which are the root cause of global warming and pollution. In this study, carbon nanotubes (CNTs) incorporated Z-scheme assembly of AgBr/TiO2 was developed for photocatalytic H2 production under visible light irradiations. Synthesized photocatalysts were characterized through transmission electron microscope (TEM), X-ray photoelectron spectra (XPS), X-ray diffractometer (XRD), Fourier transform infrared (FTIR), photoluminescence spectra (PL), Brunauer Emmet-Teller(BET), and UV-vis spectroscopy analysis techniques. The composite photocatalysts exhibited a H2 production of 477 ppm which was three-folds higher than that produced by TiO2. The good performance was attributed to the strong interaction of three components and the reduced charge recombination, which was 89 and 56.3 times lower than the TiO2 and AgBr/TiO2. Furthermore, the role of surface acidic and basic groups was assessed and the photocatalytic results demonstrated the importance of surface functional groups. In addition, the composites exhibited stability and reusability for five consecutive cycles of reaction. Thus, improved performance of the photocatalyst was credited to the CNTs as an electron mediator, surface functional groups, higher surface area, enhanced charge separation and extended visible light absorption edge. This work provides new development of Z-scheme photocatalysts for sustainable H2 production.


Author(s):  
Priyadarshni Karuppiah Chandran ◽  
Mahalingam Pambayan Ulagan

ABSTRACTBiologically inspired nanoparticle synthesis is currently a rapid expanding area of research in nanotechnology. Nanoparticle synthesis utilizing thebioresources such as plants and microbes appears to be a viable, low-cost, and eco-friendly approach. Especially mushrooms can be used for largescalesynthesis of silver nanoparticles as mushroom produces many proteins that reduce the silver nitrate during the biosynthesis. Silver nanoparticlescan be characterized using ultraviolet-visible (UV-VIS) spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction, scanning electronmicroscopy, energy dispersive X-ray, and transmission electron microscope. Silver nanoparticles possess high antibacterial activity since silver indifferent forms has been extensively used as a medicine for curing diseases and promote wound healing. Silver nanoparticles have high surfacespecific area, which will lead to excellent antimicrobial activity as compared with bulk metallic silver. Further, the silver nanoparticles show anticanceractivity against various cell lines such as human epidermoid larynx carcinoma (HEP-2), colon adenocarcinoma (HCT-116), breast adenocarcinoma(MCF-7), liver carcinoma (Hep-G2), and intestinal adenocarcinoma (Caco2) were well documented. This review intends to present green synthesis ofsilver nanoparticles and their application as antimicrobial and anticancer agents.Keywords: Silver nanoparticles, Bioresources, Mushroom, Antimicrobial activity, Anticancer property.


2019 ◽  
Vol 15 (4) ◽  
pp. 483-488
Author(s):  
Mohd Haiqal Abd Aziz ◽  
Mohd Hafiz Dzarfan Othman ◽  
Ahmad Fauzi Ismail ◽  
Mukhlis Abdul Rahman ◽  
Juhana Jaafar ◽  
...  

In this study, alumina-spinel composite hollow fibre membranes were fabricated from abundantly available aluminium dross waste, which can be commonly obtained from aluminium-producing factory. The hollow fibre membranes were successfully fabricated by using a combine phase inversion method and sintering technique. The effects of sintering temperatures on morphology, mechanical strength, and permeability of the hollow fibre membranes were systematically investigated. X-ray fluorescence (XRF) was used to analyze the composition of the aluminium dross waste, while x-ray diffraction analysis (XRD) were further studied to characterize the major crystalline phase of the sintered hollow fibre membranes. An increase in sintering temperatures resulted in densification of hollow fibre membrane, consequently induced the flux reduction. The presence of spinel in microstructural of hollow fibre assisted in decreasing the sintering temperature. As comparison to pure alumina membrane counterparts, this alternative ceramic hollow fibre membrane exhibited a comparable mechanical strength of 78.3-155.1 MPa with lower sintering temperatures ranging from 1350 ˚C to 1400 ˚C at ceramic loading of 40%.


Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 91
Author(s):  
Aliah Nursyahirah Kamarudin ◽  
Mohd Mustafa Awang Kechik ◽  
Siti Nabilah Abdullah ◽  
Hussein Baqiah ◽  
Soo Kien Chen ◽  
...  

The development of high-temperature superconductor (HTS) YBa2Cu3O7~δ (Y123) bulks in industrial applications were established years ago. It is one of the developments that currently attracts great attention especially in transportation, superconductor cables and wires. This study is focused on the preparation of the Y123 bulk superconductors by the thermal treatment method due to the promising ways to develop high-quality Y123 superconductors with its simplicity, low cost, and relatively low reaction temperature used during the process. Y123 were added with graphene nanoparticles (x = (0.0–1.0) wt.%). Samples were then characterized by X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and alternating current susceptibility (ACS). It was found that Y123 confirmed that the majority of phases in all the XRD patterns was the orthorhombic crystal structure and the Pmmm space group with secondary phases belonged to Y2Ba1Cu1O5 (Y211). The highest Tc obtained when graphene nanoparticles were added in the Y123 sample was x = 1.0 wt.%, followed by x = 0.5 wt.% with 92.64 and 92.59 K, respectively. From the microstructure analysis, the average grain size significantly decreased to 4.754 µm at x = 0.5 wt.%. The addition of graphene nanoparticles had disturbed the grain growth of Y123, affecting the superconducting properties of the samples. On the other hand, the intergranular critical current density, Jcm, was found to increase with graphene nanoparticle addition and had the highest value at x = 1.0 wt.%, indicating that graphene nanoparticles acted as pinning centers in the Y123 matrix.


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