Efficient Photodegradation of Thiocyanate Ions in Mining Wastewater Using a ZnO-BiOI Heterojunction.

Mining industries have long relied on cyanidation as the primary method for gold extraction, but this process generates thiocyanates as a problematic byproduct, posing challenges for wastewater treatment and recycling. The stability of thiocyanates makes their reduction or elimination in mining wastewater difficult. In this study, a p-n heterojunction of ZnO and BiOI was created and evaluated for its ability to photodegrade thiocyanate ions under simulated solar conditions. Various analytical techniques revealed a highly porous structure with a sponge-like morphology and agglomeration in the synthesized heterojunction. The compound exhibited crystalline patterns without impurity peaks, a slight red shift in absorbance, and Type IV isotherm adsorption. The synthesized heterostructure achieved the complete destruction of thiocyanate ions in less than 30 min. The investigation of different process parameters indicated that the destruction of the contaminant by the heterostructure was influenced by the initial thiocyanate concentration, which decreased as the thiocyanate concentration increased. The peak photodestruction reaction was observed at pH 7. By applying a pseudo-first-order kinetic model, it was found that increasing the catalyst mass to 15 mg raised the rate constant from 0.188 to 0.420 min-1, while increasing the pH to 10 led to a 3.5-fold reduction. The strong correlation between the observed data and the predicted values of the pseudo-first-order kinetic model was indicated by the observed (R2) values. The findings of this study hold potential significance for mining industries, as it offers a potential solution for eliminating cyanide and thiocyanates from mining wastewater. The elimination of thiocyanate generation in the cyanidation process is crucial for mining companies, making this study valuable for the industry.

ZnO-based heterojunction catalysts for the photocatalytic degradation of methyl orange dye.

In this study, a variety of ZnO-based heterojunctions with disparate wt.% doping of WO3 and BiOI have been prepared for the photodestruction of methyl orange (MO) dye in aqueous solution. The composites were analysed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, optical studies, and nitrogen adsorption-desorption isotherms. The SEM images revealed non-uniform surfaces of the ZnO-BiOI based composites while mostly nodular morphology was observed for all three samples of ZnO-WO3. As the WO3 loading increased, more clustering was detected. The analysed samples exhibited characteristic peaks representative of the triclinic phase of WO3 and the hexagonal wurtzite structure of ZnO, while the diffractogram observed from the materials displayed distinct peaks corresponding to the crystalline phases of both BiOI and ZnO in their pure forms. Further evidence of the samples' characteristics includes the presence of distinct crystalline patterns without any impurity peaks, a red shift in the absorption spectra of the heterostructure, the detection of only the reference elements, and mostly Type IV isotherm adsorption. This study identified the ZnO-[10%]BiOI and ZnO-[10%]WO3 heterojunctions as the best performing photocatalysts, as MO was completely destroyed in 120 and 90 min, respectively. Thus, confirming 10% wt. as the optimal doping concentration for the best photo-activity in this study. The impact of varying process parameters demonstrates that at an elevated photocatalyst mass of 40 mg, both heterojunctions effectively degraded MO. The photodegradation efficiency of MO was more pronounced in strong acidic conditions (pH 2) when compared to high alkaline conditions (pH 11) for the ZnO-[10%]BiOI heterostructure. However, a decrease in performance was observed for both strong acidic and high alkaline pH values when the ZnO-[10%]WO3 heterostructure was applied. The kinetic analysis of the photodegradation study reveals that all the photodegradation experiments can be represented by the pseudo-first-order kinetic model. The findings from this investigation propose that the ZnO-[10%]BiOI heterojunction photocatalyst holds significant potential for the effective treatment of dye-contaminated wastewater.

The Nature of the Passive Layer (and Spalled Corrosion Products) on Nonferrous Alloys in Aqueous Corrosive Media-Editorial.

Mild steel and various stainless steels are the workhorse alloys in construction and process industries, used in a myriad of applications [...].

MoS2@ZnO Nanoheterostructures Prepared by Electrospark Erosion for Photocatalytic Applications.

MoS2@ZnO nanoheterostructures were synthesized by electrospark erosion of zinc granules in a hydrogen peroxide solution and simultaneous addition of MoS2 nanostructured powder into the reaction zone. The morphology, size of the crystallites, as well as elemental and phase composition of the prepared structures, were examined using transmission electron microscopy and X-ray diffraction analysis. It was found that the synthesized products represent heterostructures containing MoS2 nanoparticles formed on ZnO nanoparticles. Raman spectroscopy and photoluminescence analysis were also used for characterization of the prepared heterostructures. The obtained MoS2@ZnO nanostructures revealed an intense broad emission band ranging from 425 to 625 nm for samples with different fractions of MoS2. Photocatalytic measurements showed that the maximal hydrogen evolution rate of the prepared nanoheterostructures was about 906.6 µmol·g-1·h-1. The potential of their application in photocatalytic water splitting was also estimated.

Crystal structure of (E)-4-benzyl-idene-6-phenyl-1,2,3,4,7,8,9,10-octa-hydro-phenanthridine.

The preparation of the title compound, C26H25N, was achieved by the condensation of an ethano-lic mixture of benzaldehyde, cyclo-hexa-none and ammonium acetate in a 2:1:1 molar ratio. There are two crystallographically independent mol-ecules in the asymmetric unit. The two cyclo-hexyl rings adopt an anti-envelope conformation with the benzyl moiety adopting a cis conformation with respect to the nitro-gen atom of the phenanthridine segment. In the crystal, mol-ecules are linked through C-H⋯N inter-actions into hydrogen-bonded chains that are further arranged into distinct layers by weak offset π-π inter-actions.

Dibenzoyl-methane Derivatives as a Potential and Exciting New Therapy for the Treatment of Childhood Bone Cancer.

Childhood bone cancer though rare, has very limited treatment choices, with poor survival rates and often involving amputation. We developed a novel molecule, 2', 4'-dihydroxy-dithion-dibenzoyl-methane and tested it on hepatic, colon, lung and osteoblast cancer cell lines. Thionylation of 2', 4'- dihydroxydibenzoylmethane led to selective targeting of bone cancer cells, stopping their growth and leading to their death without affecting non-cancerous cells within the bone marrow or other non-malignant cells.

Toxicological and analytical assessment of e-cigarette refill components on airway epithelia.

There are over 2.6 million users of e-cigarettes in the United Kingdom alone as they have been promoted as a safer alternative to traditional cigarettes. The addition of flavours and aromas has also proven to be popular with younger generations. In this review, we survey the range of studies in the short timeframe since e-cigarettes reached the market to draw attention to the health associated risks and benefits of their introduction. We complement this review with a case study reporting on the composition of selected e-cigarette refills with particular emphasis on the toxicological activity of its components on lung cells.

Crystal structure of 1H-imidazol-3-ium 2-(1,3-dioxoisoindolin-2-yl)acetate.

The title salt, C3H5N2 (+)·C10H6NO4 (-), was obtained during a study of the co-crystallization of N'-[bis-(1H-imidazol-1-yl)methyl-ene]isonicotinohydrazide with (1,3-dioxoisoindolin-2-yl)acetic acid under aqueous conditions. The 1,3-dioxoisoindolinyl ring system of the anion is essentially planar [maximum deviation = 0.023 (2) Å]. In the crystal, cations and anions are linked via classical N-H⋯O hydrogen bonds and weak C-H⋯O hydrogen bonds, forming a three-dimensional network. Weak C-H⋯π inter-actions and π-π stacking inter-actions [centroid-centroid distances = 3.4728 (13) and 3.7339 (13) Å] also occur in the crystal.

N'-[(E)-2-Chloro-benzyl-idene]-2-(6-meth-oxy-naphthalen-2-yl)propano-hydrazide.

In the title compound, C21H19ClN2O2, the benzene ring and the naphthalene ring system are oriented at a dihedral angle of 65.24 (10)°. In the crystal, N-H⋯O, C-H⋯N and C-H⋯O hydrogen bonds link the mol-ecules, forming chains along the b-axis direction. Further C-H⋯O hydrogen bonds link the chains, forming corrugated sheets lying parallel to (10-1).

A new polymorph of N-(2-{N'-[(1E)-2-hy-droxy-benzyl-idene]hydrazinecarbon-yl}phen-yl)benzamide.

The title compound, C21H17N3O3, is a new polymorph of an already published structure [Shashidhar et al. (2006 ▶). Acta Cryst. E62, o4473-o4475]. The previously reported structure crystallizes in the monoclinic space group C2/c, whereas the structure reported here is in the tetra-gonal space group I41/a. The bond lengths and angles are similar in both structures. The mol-ecule adopts an extended conformation via intra-molecular N-H⋯O and O-H⋯N hydrogen bonds; the terminal phenyl ring and the hy-droxy-lphenyl ring are twisted with respect to the central benzene ring by 44.43 (7) and 21.99 (8)°, respectively. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, weak C-H⋯O hydrogen bonds and weak C-H⋯π inter-actions into a three-dimensional supra-molecular network.