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The current study is about the synthesis of nanoparticles (NPs) of cobalt oxide (CO) and cobalt sulfide (CS) followed by their nanocomposites as CO/CS and CO/CS/CNT by ultrasonication approach. The addition of carbon-based materials in the oxides and sulfides enhances their performance by developing physico-chemical interactions. Prepared NPs were utilized for the photodegradation of organic contaminants. The characteristics, as well as the efficiency of the prepared samples, have been systematically examined by X-ray diffraction (XRD) technique, Fourier transform infrared spectroscopy (FTIR), and UV-vis spectroscopy. Photocatalytic activities of bare samples and synthesized nanocomposites were tested for the degradation of methyl orange (MO) using a xenon lamp. The percentage degradation of dye was 24.14%, 57.94%, 71.66%, and 85.04% in the presence of CO, CS, CO/CS, and CO/CS/CNT, respectively. Crystal violet (CV), Rhodamine B (rho-B), and industrial wastewater were also degraded by the ternary composite. The comparative studies showed the best performance of CO/CS/CNT, which enhanced the generation of electron-hole pairs by absorption of photons of incoming radiations, increased charge separation, and maximum surface area for adsorption. [ABSTRACT FROM AUTHOR]

Salbutamol (SAL) is a β2-agonist and belongs to a category of drugs used to maintain bronchodilation. Unfortunately, some athletes have misused these medications as performance-enhancing drugs to improve their performance. Thus, to ensure fair competition, the World Anti-Doping Agency (WADA) prohibits its usage among athletes. Herein, we have designed, a novel, non-enzymatic electrochemical sensor by wrapping benzimidazolium-1-acetate liquid (IL) around Co3O4 (derived from the pyrolysis of ZIF-67) embedded in N-doped porous C (IL@NC–Co), for the detection of SAL in urine for dope tests. The fabricated material was characterized through SEM, XRD, and FTIR techniques, which confirmed the successful synthesis of the material. The designed novel IL@NC–Co electrochemical sensor showed excellent electrocatalytic activity because of its highly porous structure and fast electron transfer due to the presence of carboxyl functional groups and aromatic rings in IL, thus resulting in an enhanced current response. The developed sensor exhibited excellent selectivity even in the presence of co-existing interferences and good sensitivity (0.0039 μA nM−1 cm−2) with a linear response to SAL concentrations ranging from 2 to 2500 μM with a low detection limit of 0.0014 nM. The designed electrode showed an excellent stability of 96.58% with RSD 2.45% even after 24 h. The fabricated electrode was successfully utilized for selective monitoring of SAL in urine samples, thus suggesting the reliability of the designed system to be applicable for dope tests. [ABSTRACT FROM AUTHOR]

Highly efficient 2D/2D layered heterostructure of nickel oxide (NiO) and molybdenum sulphide (MoS2) has been fabricated for the photoelectrochemical (PEC) water splitting and degradation of Bromophenol Blue (BPB) under visible light. The XRD spectra confirm mixed characteristic peaks of MoS2 and NiO in the nanocomposite. SEM displays flower-like patterns of pure and composite material with the 2D nanosheets layer structure. The band gap reduction (2.25–1.72 eV) is due to the incorporation of NiO in MoS2 for visible light harvesting. TEM confirms the homogeneous distribution of 2D/2D nanosheets. The excellent interfacial coupling in strong 2D/2D interactions boost the electro and photocatalytic activities. 15.0% NiO showed excellent PEC activity toward OER with maximum photocurrent density of 1.57 mA cm−2, which influenced the overall water splitting at lower potential, ensuring visible photoresponse. The maximum photodegradation performance for highly toxic BPB was achieved by the photocatalyst, which contains 15.0 wt% NiO in NiO/MoS2 composite. It displays the highest conversion efficiency (∼87.0%) for BPB owing to exposed active sites via Mo–Ni–S linkages. Defects in NiO/MoS2 offer favorable reaction dynamics to PEC OER, which are helpful in tuning the band potentials. [ABSTRACT FROM AUTHOR]

This work provides an environmental approach to utilise Blast furnace slag (BFS) waste for the processing of aluminium oxide (Al2O3-BFS) as an efficient adsorbent for uranium removal from wastewater. The composition of BFS is less variable and this makes it a low cost and abundant raw material for preparing a solid base Al2O3-BFS. The silica material was initially removed and then the aluminium content was separated by precipitation with sodium hydroxide depending on pH control (pH 5.5). The raw BFS and Al2O3-BFS were characterised via various methods, such as; XRD, Zeta potential, N2 adsorption-desorption isotherm, DLS, and FT-IR. BFS exhibited the typical type III isotherm with an H3-type hysteresis loop. The curve of Al2O3-BFS exhibited the typical IV isotherms with a H2-type hysteresis loop. The BET surface and average pore sizes of the Al2O3-BFS are 137.7 m2 g-1 and 3.9 nm, respectively. Experiments and discussions were performed in terms of balance, isothermal, kinetic, and applicability. The finding provides proof of the ability of synthesised Al2O3-BFS to remove U(VI) ions from wastewater as an efficient adsorbent with a maximum sorption capacity value of 62 mg/g. The pseudo second, Langmuir and Dubinin-Radushkevich models were found suitable to explain the rate kinetics and isotherm of uranium removal. Uranium sorption on Al2O3-BFS may occur via inner-sphere complex and ion-exchange between uranium ions and HO-Al2O3-BFS groups. The higher elution efficiency of Al2O3-BFS indicates a promising adsorbent in the technology of U(VI) removal. [ABSTRACT FROM AUTHOR]

Industrialization and urbanization have now become major factors in damaging different segments of the environment. Synthesis of novel nanomaterials for the removal of dyes and free radicals from aqueous medium has become a challenge for the researchers. The present work describes formation of novel-franklinite (ZnFe2O4) nanoparticles (FNPs) which have been synthesized adopting economical route of green method using extracts of fresh and dried leaves of Coriandrum sativum. The fabricated NPs were characterized employing state of the art analytical techniques including UV-visible, FTIR, SEM and XRD. The nanocatalyst exhibited excellent catalytic properties for the degradation of eosin yellow up to 86 % in 22 min and 90 % in 16 min using zinc-ferrite NPs synthesized using dried and fresh leaves respectively. Antioxidant activity of ZnFe2O4 in terms of DPPH and ABTS free radicals scavenging was also determined. Nanoparticles synthesized using fresh leaves exhibited better antiradical potential in comparison to NPs synthesized dried leaves. Therefore, synthesis of FNPs with active features can be achieved using extract of fresh plant. Franklinite NPs can be used as promising photocatalyst for the degradation of organic pollutants and scavenging of free radicals. [ABSTRACT FROM AUTHOR]

The work reports a facile synthesis of high thermally stable nanocrystalline anatase TiO2 nanoparticles (NPs) doped with different atomic concentrations (0.5, 1.0, 3.0, and 6.0%) of Gd3+ and Nd3+ ions by a template-free and one-step solvothermal process, using titanium(IV) butoxide as a titanium precursor and dimethyl sulfoxide (DMSO) as a solvent. The structure and morphology of the Gd3+, Nd3+, and 0.5%Gd3+-0.5%Nd3+/doped TiO2 NPs have been characterized by using various analytical techniques. The Gd3+/ and Nd3+/TiO2 molar ratios were found to have a pronounced impact on the crystalline structure, size, and morphology of TiO2 NPs. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies revealed the proper substitution of Ti4+ by Gd3+ and Nd3+ ions in the TiO2 host lattice. The as-prepared Gdx/TiO2, Ndx/TiO2, and Gd1.0/Ndx/TiO2 bimetallic NPs, x = 0.5, 1.0, 3.0, and 6%, have been investigated as electrocatalysts for hydrogen evolution reaction (HER) in 1.0 M KOH solution using a variety of electrochemical techniques. At any doping percentage, the Gd1.0/Ndx/TiO2 bimetallic NPs showed higher HER catalytic performance than their corresponding counterparts, i.e., Gdx/TiO2 and Ndx/TiO2. Upon increasing the Nd content from 0.5 to 6.0%, the HER catalytic performance of the Gd1.0/Ndx/TiO2 bimetallic NPs was generally enhanced. Among the studied materials, the bimetallic Gd1.0/Nd6.0/TiO2 NPs emerged as the most promising catalyst with an onset potential of −22 mV vs. RHE, a Tafel slope of 109 mV dec−1, and an exchange current density of 0.72 mA cm−2. Such HER electrochemical kinetic parameters are close to those recorded by the commercial Pt/C (onset potential: −15 mV, Tafel slope: 106 mV dec−1, and exchange current density: 0.80 mA cm−2), and also comparable with those measured by the most active electrocatalysts reported in the literature. The synergistic interaction of Gd and Nd is thought to be the major cause of the bimetallic catalyst's activity. [ABSTRACT FROM AUTHOR]