Metal-free phosphorus and boron-doped graphitic carbon nitride/zeolite hetero-linked particles for highly efficient green hydrogen production in methanol.

Herein, the development of phosphorus and boron-doped graphitic carbon nitride/zeolite (P- and B-doped g-C3N4-zeolite) catalyst under three-step heating conditions was performed. The first step is to prepare g-C3N4 synthesis from urea at 500 °C. In the second step, the production of a B-doped zeolite-g-C3N4 catalyst by calcination of g-C3N4 and zeolite was obtained at a ratio of 1:1 with boric acid at 500 °C. In the third step, the obtained B-doped zeolite- g-C3N4 catalyst consists of the preparation of B- and P-doped g-C3N4-zeolite catalyst as a result of the hydrothermal method with phosphoric acid. Characterization studies of the obtained catalysts were carried out with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). These obtained catalysts were used as a metal-free catalyst in the production of hydrogen (H2-P) by sodium borohydride in methanol(NaBH4-MR) for the first time in the literature. The hydrogen production rate (HGR) value for P- and B-doped g-C3N4-zeolite catalysts was 6250 ml min-1 g-1.

Phosphorus and oxygen co-doped carbon particles based on almond shells with hydrothermal and microwave irradiation process for adsorption of lead (II) and cadmium (II).

In this study, the production of activated carbon based on almond shells by microwave heating with KOH activation and then the modification of activated carbon with phosphorus and oxygen as a result of hydrothermal heating with phosphoric acid were carried out to increase the Cd(II) and Pb(II) adsorption efficiency. The resulting materials were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric/differential thermal analyzer (TG-DTA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and nitrogen adsorption. Adsorption performance, kinetics and thermodynamics of phosphorus, and oxygen-doped activated carbons were evaluated. The results showed that the adsorption of both Cd(II) and Pb(II) on phosphorus and oxygen-doped activated carbons obeyed the Langmuir isotherm and pseudo-second-order kinetics. The adsorption capacity values (Qm) obtained from the Langmuir isotherm for Cd(II) and Pb(II) adsorption were 185.18 mg/g and 54.64 mg/g, respectively. At the same time, the adsorption mechanism of Pb(II) and Cd(II) on the respective adsorbents was evaluated. As a result of phosphorus and oxygen atoms, Lewis base sites on carbon atoms and Lewis acid sites on phosphorus atoms are likely to form on the surface. These Lewis base sites can act as important active sites in adsorption reactions, especially of positively charged Pb(II) and Cd(II) ions.

Iodine adsorption and electrochemical double-layer capacitor characteristics of activated carbon prepared from low-cost biomass.

The efficient adsorption application and electric double-layer capacitor material with low-cost biomass-based activated carbon materials have been quite common recently. In this study, chestnut shell-based activated carbons were produced by chemical activation. ZnCl2, H3PO4, and KOH agents were used for chemical activation. The obtained activated carbon, iodine adsorption from aqueous solutions, and its use as an electro capacitor were investigated. The scanning electron microscope, nitrogen adsorption/desorption, and Fourier transform infrared spectroscopy were used for characterization. The values of surface area and iodine adsorption capacity of the chestnut shell-based activated carbon are 1544 m2 g-1 and 1525 mg g-1. As a result, a specific capacitance of 97 Fg-1 with chestnut shell-based activated carbon was obtained in a 1 M KCl electrolyte for the electrochemical double-layer capacitor. This study shows that activated carbon based on the chestnut shell can be used both as an electrochemical energy storage material and as an adsorbent in iodine adsorption.

Analytical Methods on Determination in Pharmaceuticals and Biological Materials of Chloroquine as Available for the Treatment of COVID-19.

With the outbreak caused by the severe acute respiratory syndrome coronavirus (COVID-19), people's health and existing economies on a global scale are seriously threatened. Currently, most of the countries all over the world are studying extensively to better understand the antimalarial chloroquine (CQ) and hydroxychloroquine (HCQ) for therapeutic purposes due to the COVID-19 outbreak. However, CQ and HCQ can have serious side effects, from psychiatric effects to sudden death. Therefore, a faster and more effective detection method is needed to monitor drug concentrations. In this review, a large study was conducted on the detection techniques and quantitative determination methods of CQ and its related metabolites. In this review, chromatography, electrophoresis, electroanalytical, spectroscopic, and immunological methods for CQ and related metabolites are discussed extensively. It is hoped that a better understanding of the CQ used for therapeutic purposes in the COVID-19 outbreak will be provided.

Electroanalytical Approaches for Determination of Prostate Cancer Drugs in Biological Samples and Dosage Forms.

Prostate cancer is the second most common malignant type of cancer in men and fifth among fatal types of cancer. Because drugs used in prostate cancer, such as in many other drugs, are also present in low concentrations in body fluids, it is important to develop highly sensitive and sensitive methods that allow the correct amount of prostate cancer drugs to be determined at low concentrations in biological specimens. Electrochemical approaches for the quantitation of prostate cancer drugs have several advantages over other common techniques, including sensitive, selective, fast, broad linear concentration range. Over the years, various modified working electrodes such as graphite, glassy carbon, carbon paste electrode, carbon composites, and nanotubes have been developed and used in various forms for electroanalytical determinations of prostate cancer drugs. One of the important developments in the electroanalytical chemistry is the surface modification of electrodes. The various sensing strategies for the electrochemical detection techniques such as voltammetry, polarography, amperometry, potentiometry have been used for prostate cancer drugs. This review focuses on studies published over the past years on sensitive and selective detection of prostate cancer drugs in biological fluids and dosage forms using electrochemical methods.

Chromatographic Methods for Determination of Drugs Used in Prostate Cancer in Biological and Pharmacological Samples.

Prostate cancer is the second most common cancer and the fifth leading cause of cancer deaths in men worldwide. This review article contains a summary of analyzes performed by chromatographic methods used for the determination of abiraterone acetate, bicalutamide, cabazitaxel, docetaxel, enzalutamide, flutamide, goserelin acetate, leuprolide acetate, and mitoxantrone hydrochloride drugs used in prostate cancer applications in biological and pharmacological samples. In this review, sample preparation procedures, chromatographic procedures, and detectors used for analytical determinations of these drugs are discussed.

Overview on the Surface Functionalization Mechanism and Determination of Surface Functional Groups of Plasma Treated Carbon Nanotubes.

The use of carbon materials for many applications is due to the unique diversity of structures and properties ranging from chemical bonds between the carbon atoms of the materials to nanostructures, crystallite alignment, and microstructures. Carbon nanotubes and other nanoscale carbonaceous materials draw much attention due to their physical and chemical properties, such as high strength, high resistance to corrosion, electrical and thermal conductivity, stability and a qualified adsorbent. Carbon-based nanomaterials, which have a relatively large specific area and layered structure, can be used as an adsorbent for efficient removal of organic and inorganic contaminants. However, one of the biggest obstacles to the development of carbon-based nanomaterials adsorbents is insolubility and the lack of functional groups on the surface. There are several approaches to introduce functional groups on carbon nanotubes. One of these approaches, plasma applications, now has an important place in the creation of surface functional groups as a flexible, fast, and environmentally friendly method. This review focuses on recent information concerning the surface functionalization and modification of plasma treated carbon nanotube. This review considers the surface properties, advantages, and disadvantages of plasma-applied carbon nanotubes. It also examines the reaction mechanisms involved in the functional groups on the surface.

An Overview of Analytical Methods for the Determination of Monoamine Oxidase Inhibitors in Pharmaceutical Formulations and Biological Fluids.

Monoamine oxidase inhibitors (MAOIs) were the first type of antidepressant developed. MAOIs elevate the levels of norepinephrine, serotonin, and dopamine by inhibiting an enzyme called monoamine oxidase. They are also used in the treatment of Parkinson's disease, tuberculosis, and several other disorders. Therefore, it is very important to develop efficient analytical methods for monitoring and management. There are two isoforms of monoamine oxidase, MAO-A and MAO-B. In this article, analyses of MAOIs in pharmaceutical formulations and biological fluids were reviewed from 2000 to the present, including all types of chromatographic, spectrophotometric, electrophoretic, and voltammetric techniques, focusing on isoniazid, tranylcypromine, moclobemide, rasagiline, and selegiline.

Analytical Strategies for the Determination of Norepinephrine Reuptake Inhibitors in Pharmaceutical Formulations and Biological Fluids.

Norepinephrine reuptake inhibitors (NRIs) are a class of antidepressant drugs that act as reuptake inhibitors for the neurotransmitters norepinephrine and epinephrine. The present review provides an account of analytical methods published in recent years for the determination of NRI drugs. NRIs are atomoxetine, reboxetine, viloxazine and maprotiline. NRIs with less activity at other sites are mazindol, bupropion, tapentadol, and teniloxazine. This review focuses on the analytical methods including chromatographic, spectrophotometric, electroanalytical, and electrophoresis techniques for NRI analysis from pharmaceutical formulations and biological samples. Among all of the published methods, liquid chromatography with UV-vis or MS-MS detection is the most popular technique. The most the common sample preparation techniques in the analytical methods for NRIs include liquid-liquid extraction and solid-phase extraction. Besides the analytical methods for single components, some of the simultaneous determinations are also included in this review.

Preparation and characterization of activated carbon from acorn shell by physical activation with H2O-CO2 in two-step pretreatment.

Activated carbons have been prepared by physical activation with H2O-CO2 in two-step pre-treatment including ZnCl2-HCl from acorn shell at 850 °C. The active carbons were characterized by N2 adsorption at 77 K. Adsorption capacity was demonstrated by the iodine numbers. The surface chemical characteristics of activated carbons were determined by FTIR spectroscopic method. The microstructure of the activated carbons prepared was examined by scanning electron microscopy. The maximum BET surface area of the obtained activated carbon was found to be around 1779 m(2)/g.

The natural diatomite from caldiran-van (Turkey): electroanalytical application to antimigraine compound naratriptan at modified carbon paste electrode.

This paper is the first report describing the characterization of local diatomite of Caldiran-Van region (Eastern Anatolia, Turkey). Special attention was paid to the ability of its electroanalytical performance at modified electrodes and to the potential application of diatomite-modified electrode. For this purpose, the determination of Naratriptan which is a novel oral triptan (5-hydroxytryptamine receptor agonist) in migraine treatment, by means of a carbon paste electrode modified with 10% (w/w) of diatomite was studied using cyclic and square-wave voltammetry. The experimental conditions that affect the electrode reaction process were studied in terms of pH of the supporting electrolyte, scan rate, accumulation variables, modifier composition and square-wave parameters. Using square-wave stripping mode, the drug yielded a well-defined voltammetric response in Britton-Robinson buffer, pH 4.0 at 0.84 V (vs. Ag/AgCl) (a pre-concentration step being carried out with an open circuit at 120 s). The process could be used to determine Naratriptan concentrations in the range 5x10(-7)-9x10(-7) M, with a detection limit of 1.25x10(-7) M (46.5 mug L(-1)). The applicability of the method to spiked human urine samples was illustrated.