Fabrication of Photo-Responsive Mesh Membrane with Surface-Engineered Wettability for Oil-Water Separation and Photocatalytic Degradation of Organic Pollutants.

A photo-responsive TiO-coated stainless-steel mesh membrane (TiO@SSM), possessing unique surface wettability, was fabricated. This TiO@SSM membrane is found to be capable of separating oil and water from oily water and has the potential to carry out photocatalytic self-cleaning and/or the degradation of organic pollutants present in water. The fabrication of TiO@SSM is quite simple: titanium dioxide (TiO) nanoparticles were spray-coated onto stainless steel microporous mesh (SSM) substrates and annealed at the temperature of 500 °C.

Thermally Sensitized Membranes for Crude Oil-Water Remediation under Visible Light.

Effective remediation of produced water requires separating crude oil-water mixture and removing the dissolved organic pollutants. Membranes with selective wettability for water over oil enable the gravity-driven separation of an oil-water mixture by allowing water to permeate through while repelling oil. However, these membranes are often limited by their inability to remove the dissolved organic pollutants.

Investigation of the survival viability of cervical cancer cells (HeLa) under visible light induced photo-catalysis with facile synthesized WO/ZnO nanocomposite.

The photo catalytic degradation, a proven chemical process used for the decontamination of organic/inorganic pollutants and microorganisms in water was implemented. In this work for the selective killing of cervical cancer cells () by using nano-composite of (Zinc Oxcide), (tungsten oxide) and () as a photo-catalyst under the irradiation of visible light. All the three nanostructured semiconducting materials (WO3, ZnO and n-WO3/ZnO) were synthesized by facile chemical precipitation method and their morphological and optical characterization studies were carried out to elucidate the observed enhancement in the photo-catalytic killing of HeLa cancer cells with n-WO3/ZnO as a photo-catalyst.

Laser Induced Anchoring of Nickel Oxide Nanoparticles on Polymeric Graphitic Carbon Nitride Sheets Using Pulsed Laser Ablation for Efficient Water Splitting under Visible Light.

A visible-light-active nickel oxide-graphitic carbon nitride (NiO@g-CN) hetero-structured nanocomposite was synthesized for the first time by pulsed laser ablation in liquid and used as a photoanode material in photoelectrochemical water-splitting reaction with a solar simulator. It was found that the photoelectrochemical performance of PLAL synthesized NiO@g-CN nanocomposite as photoanode, compared to g-CN as photoanode showed fourfold enhancements in photocurrent density under visible light. FT-IR, XRD, FE-SEM, and EDX consistently showed the proper anchoring of nano-sized NiO on g-CN.

Method for Visible Light-Induced Photocatalytic Degradation of Methylparaben in Water Using Nanostructured Ag/AgBr@m-WO.

An efficient method of photocatalytic degradation of methylparaben in water using Ag nanoparticles (NPs) loaded AgBr-mesoporous-WO composite photocatalyst (Ag/AgBr@m-WO ), under visible light is presented. In this process, quantification of methylparaben in water was carried out by high-performance liquid chromatography (HPLC) and the HPLC results showed a significant reduction of methylparaben in water due to the enhanced of photocatalytic degradation efficiency of Ag/AgBr@m-WO . For the material synthesis, highly ordered mesoporous-WO (m-WO ) was initially synthesized by sol-gel method and AgBr nanoparticles (NPs) were subsequently introduced in the pores of m-WO , and finally, the Ag nanoparticles were introduced by light irradiation.

Photo-catalytic Killing of HeLa Cancer Cells Using Facile Synthesized Pure and Ag Loaded WO Nanoparticles.

Chemotherapy, the most commonly used therapeutic method for cancer, has the inherent constraint of low bioavailability. A number of physical cancer therapeutic treatments like radiation, ultrasound, photo-acoustic/photo thermal, microwave therapies are based on locating the afflicted sites with the help of imaging, but the serious drawbacks of these treatment options are that they damage the neighboring normal tissues and/or induce undesired cancer metastasis. In addition, these methods of treatment are very expensive and not in the reach of a common man especially in the developing countries.

Fabrication and Wettability Study of WO Coated Photocatalytic Membrane for Oil-Water Separation: A Comparative Study with ZnO Coated Membrane.

Superhydrophilic and underwater superoleophobic surfaces were fabricated by facile spray coating of nanostructured WO on stainless steel meshes and compared its performance in oil-water separation with ZnO coated meshes. The gravity driven oil-water separation system was designed using these surfaces as the separation media and it was noticed that WO coated stainless steel mesh showed high separation efficiency (99%), with pore size as high as 150 µm, whereas ZnO coated surfaces failed in the process of oil-water separation when the pore exceeded 50 µm size. Since, nanostructured WO is a well known catalyst, the simultaneous photocatalytic degradation of organic pollutants present in the separated water from the oil water separation process were tested using WO coated surfaces under UV radiation and the efficiency of this degradation was found to be quite significant.

Direct spectral analysis and determination of high content of carcinogenic bromine in bread using UV pulsed laser induced breakdown spectroscopy.

Laser induced breakdown spectroscopy (LIBS) was applied for the detection of carcinogenic elements like bromine in four representative brands of loaf bread samples and the measured bromine concentrations were 352, 157, 451, and 311 ppm, using Br I (827.2 nm) atomic transition line as the finger print atomic transition. Our LIBS system is equipped with a pulsed laser of wavelength 266 nm with energy 25 mJ pulse(-1), 8 ns pulse duration, 20 Hz repetition rate, and a gated ICCD camera.

Study of factors governing oil-water separation process using TiO₂ films prepared by spray deposition of nanoparticle dispersions.

Surfaces which possess extraordinary water attraction or repellency depend on surface energy, surface chemistry, and nano- and microscale surface roughness. Synergistic superhydrophilic-underwater superoleophobic surfaces were fabricated by spray deposition of nanostructured TiO2 on stainless steel mesh substrates. The coated meshes were then used to study gravity driven oil-water separation, where only the water from the oil-water mixture is allowed to permeate through the mesh.

Detection of trace elements in nondegradable organic spent clay waste using optimized dual-pulsed laser induced breakdown spectrometer.

The detection of trace elements present in nondegradable organic spent clay waste has been carried out using an optimized dual-pulsed laser induced breakdown spectrometer. The two laser pulses at 1064 and 266 nm were collinearly collimated and focused on the sample surface in order to enhance the signal intensity. The atomic transition lines at 568.

Detection of toxic metals (lead and chromium) in talcum powder using laser induced breakdown spectroscopy.

A laser induced breakdown spectroscopic (LIBS) system was developed using a 266 nm laser and a high-resolution spectrograph (Andor SR 500 i-A) to detect the trace levels of the highly toxic metals such as lead and chromium present in different brands of talcum powder available in the local market. The strongest atomic transition lines of lead (Pb) (405.7 nm) and chromium (Cr) (425.

Detection of chloride in reinforced concrete using a dualpulsed laser-induced breakdown spectrometer system: comparative study of the atomic transition lines of Cl I at 594.85 and 837.59 nm.

The presence of chloride in reinforced concrete can cause severe damage to the strength and durability of buildings and bridges. The detection of chloride in concrete structures at early stages of the corrosion buildup process is, therefore, very important. However, detection of chlorine in trace amounts in concrete is not a simple matter.

Design, fabrication, and optimization of photo acoustic gas sensor for the trace level detection of NO2 in the atmosphere.

Photoacoustic (PA) gas sensor for the detection of hazardous NO(2) with detection limit as low as few part per billion by volume (ppbV) has been designed and tested with pulsed UV laser. Some design optimization factors such as the optimum cell geometry, buffer gas etc has been proposed. It was found that a cylindrical cell with many acoustic filters considerably dampens the noise level and also argon as a buffer gas improves the photoacoustic signal level and this combination substantially improved the signal to noise ratio and the limit of detection.

High-sensitivity detection of hazardous SO(2) using 266 nm UV laser.

Pulsed laser resonant photoacoustic spectroscopy was applied for detection of highly toxic SO(2) with 266 nm as the excitation source. An extra-cavity longitudinal resonant cell, was designed and fabricated to enhance the sensitivity of the system, which is capable of detecting the trace amount of SO(2). As a process of signal-to-noise ratio optimization, the parametric dependence of the PA signal was carried out and the sensitivity achieved with our system was as low as 4 ppb, which is considered to be a sufficient level for the detection of ambient SO(2) in the atmosphere.