Template-free synthesis of nanostructured Cd(x)Zn(1-x)S with tunable band structure for H2 production and organic dye degradation using solar light.

We have demonstrated a template-free large-scale synthesis of nanostructured Cd(x)Zn(1-x)S by a simple and a low-temperature solid-state method. Cadmium oxide, zinc oxide, and thiourea in various concentration ratios are homogenized at moderate temperature to obtain nanostructured Cd(x)Zn(1-x)S. We have also demonstrated that phase purity of the sample can be controlled with a simple adjustment of the amount of Zn content and nanocrystalline Cd(x)Zn(1-x)S(x = 0.5 and 0.9) of the hexagonal phase with 6-8 nm sized and 4-5 nm sized Cd(0.1)Zn(0.9)S of cubic phase can be easily obtained using this simple approach. UV-vis and PL spectrum indicate that the optical properties of as synthesized nanostructures can also be modulated by tuning their compositions. Considering the band gap of the nanostructured Cd(x)Zn(1-x)S well within the visible region, the photocatalytic activity for H2 generation using H2S and methylene blue dye degradation is performed under visible-light irradiation. The maximum H2 evolution of 8320 µmol h(-1)g(-1) is obtained using nanostructured Cd(0.1)Zn(0.9)S, which is four times higher than that of bulk CdS (2020 µmol h(-1) g(-1)) and the reported nanostructured CdS (5890 µmol h(-1)g(-1)). As synthesized Cd(0.9)Zn(0.1)S shows 2-fold enhancement in degradation of methylene blue as compared to the bulk CdS. It is noteworthy that the synthesis method adapted provides an easy, inexpensive, and pollution-free way to synthesize very tiny nanoparticles of Cd(x)Zn(1-x)S with a tunnable band structure on a large scale, which is quite difficult to obtain by other methods. More significantly, environmental benign enhanced H2 production from hazardous H2S using Cd(x)Zn(1-x)S is demonstrated for the first time.

Evaluation of the Orofacial Features in the Victims of Abuse and Neglect of 5-16-Year-old Age Children.

BACKGROUND: Oral cavity may be considered a pivotal focal point in physical assault or abuse because of its implication in communication and nutrition. Dentists trained in a child abuse curriculum can provide valuable information and assistance to physicians about oral and dental aspects of child abuse and neglect. The present study was conducted to evaluate the orofacial features of children between the age group of 5-16 years suspected to be victims of child abuse/neglect. MATERIALS AND METHODS: This study was conducted on 250 children ranging between 5 and 16 years were enrolled in the study. All the participants were suspected to be victims of child abuse/neglect. The orofacial features were carefully examined by a well-trained dentist. RESULTS: Two hundred and fifty children were enrolled in the study. Seventy-two children (30%) presented with laceration of various sites including lip (n = 13), frenum (n = 8), buccal mucosa (n = 26), palate (n = 16), and floor of the mouth (n = 9). Twenty-nine participants exhibited the features of avulsion (11.6%). Eighteen children revealed dento-alveolar fractures, 104 presented with dental caries (41.6%), 19 presented with missing teeth (7.6%), all the candidates presented with deposits (100%). CONCLUSION: Careful intraoral and perioral examination of the participants victimized to abuse and/neglect is necessary as the oral cavity is a central focus for physical abuse, which may be allied to its importance in communication and nutrition. Physicians and dentists should work together to increase the prevention, detection, and treatment of these conditions.

A hierarchical SnS@ZnIn2S4 marigold flower-like 2D nano-heterostructure as an efficient photocatalyst for sunlight-driven hydrogen generation.

Herein, we report the in situ single-step hydrothermal synthesis of hierarchical 2D SnS@ZnIn2S4 nano-heterostructures and the examination of their photocatalytic activity towards hydrogen generation from H2S and water under sunlight. The photoactive sulfides rationally integrate via strong electrostatic interactions between ZnIn2S4 and SnS with two-dimensional ultrathin subunits, i.e. nanopetals. The morphological study of nano-heterostructures revealed that the hierarchical marigold flower-like structure is self-assembled via the nanopetals of ZnIn2S4 with few layers of SnS nanopetals. Surprisingly, it also showed that the SnS nanopetals with a thickness of ∼25 nm couple in situ with the nanopetals of ZnIn2S4 with a thickness of ∼25 nm to form a marigold flower-like assembly with intimate contact. Considering the unique band gap (2.0-2.4 eV) of this SnS@ZnIn2S4, photocatalytic hydrogen generation from water and H2S was performed under sunlight. SnS@ZnIn2S4 exhibits enhanced hydrogen evolution, i.e. 650 µmol h-1 g-1 from water and 6429 µmol h-1 g-1 from H2S, which is much higher compared to that of pure ZnIn2S4 and SnS. More significantly, the enhancement in hydrogen generation is 1.6-2 times more for H2S splitting and 6 times more for water splitting. SnS@ZnIn2S4 forms type I band alignment, which accelerates charge separation during the surface reaction. Additionally, this has been provoked by the nanostructuring of the materials. Due to the nano-heterostructure with hierarchical morphology, the surface defects increased which ultimately suppresses the recombination of the electron-hole pair. The above-mentioned facts demonstrate a significant improvement in the interface electron transfer kinetics due to such a unique 2D nano-heterostructure semiconductor which is responsible for a higher photocatalytic activity.

Solar-light-active mesoporous Cr-TiO2 for photodegradation of spent wash: an in-depth study using QTOF LC-MS.

A dark-coloured effluent called "spent wash" is generated as an unwanted product in sugarcane-based alcohol distilleries. Most distilleries discharge this effluent into soil or water without any treatment, causing water and soil pollution. Herein, we report chromium-doped TiO2 (Cr-TiO2) as a photocatalyst for the degradation of spent wash colour under natural sunlight. Cr-doped TiO2 nanoparticles were prepared using an aqueous titanium peroxide-based sol-gel method with titanium isopropoxide as the Ti precursor and chromium nitrate as the Cr precursor. To observe the effect of dopant on sol-gel behaviour and physicochemical properties, the Cr concentration was varied in the range 0.5-5 wt%. The crystallization temperature and time were optimized to obtain the required phase of Cr-TiO2. The physicochemical characteristics of the Cr-doped TiO2 catalyst were determined using X-ray diffraction, FE-SEM, FETEM, TG, XPS, the Brunauer-Emmett-Teller (BET) method, FT-IR, Raman, PL, ICP-MS, and UV visible spectroscopy. A shift in the absorption edge of TiO2 by doping with chromium suggested an increase in visible light absorption due to a decrease in the effective band gap. The application potential of the Cr-TiO2 catalyst was studied in the degradation of sugar-based alcohol distillery waste under natural sunlight, and the results were compared with those of undoped TiO2 and Degussa P25 TiO2. Degradation of the spent wash solution was monitored using UV-visible, gel permeation chromatography (GPC), and QTOF LC-MS. GPC and LC-MS showed significant changes in the molecular weight of spent wash colour-forming compounds due to the degradation reaction. QTOF LC-MS analysis suggested that acids, alcohols, glucosides, ketones, lipids, peptides, and metabolites were oxidized to low-molecular-weight counterparts. From the results, 5% Cr-TiO2 showed the highest degradation rate among all Cr-TiO2 samples, undoped TiO2, and Degussa P25 TiO2 under identical reaction conditions, with nearly 68-70% degradation achieved in 5 h.

Photodegradation of spent wash, a sugar industry waste, using vanadium-doped TiO2 nanoparticles.

Waste from the sugar cane industry and alcohol distilleries is one of the sources of water pollution, and the degradation of this effluent is a very challenging task. Photocatalytic degradation can be an attractive alternative to conventional degradation processes. A vanadium-doped TiO2 (V-TiO2) photocatalyst for the degradation of spent wash and industrial dyes has been studied and reported here. V-doped TiO2 nanoparticles were prepared using a sol-gel method based on aqueous titanium peroxide with titanium isopropoxide as the Ti precursor and V2O5 as the V precursor. In order to observe the effect of the dopant on sol-gel behaviour, physicochemical and structural properties, the concentration of V was varied between 1.0% and 5% by weight. The crystallization temperature and time were optimized to obtain the required phase of V-TiO2. The physicochemical and structural characteristics of the V-doped TiO2 catalyst were determined using Brunauer-Emmett-Teller (BET), X-ray diffraction, FESEM, TEM, TG, FT-IR, Raman, PL and UV-visible spectroscopic techniques. UV-visible analysis showed a red shift in the absorption edge of TiO2 upon doping with V metal, which suggested an increase in the absorption of visible light due to a decrease in the effective band gap. The application potential of the V-TiO2 catalyst was studied via the degradation of sugar industry waste (spent wash) and Jakofix red dye (HE 8BN) under natural sunlight, as well as a standard artificial solar energy source (Xe lamp). The highest activity was observed for a 1% V-TiO2 photocatalyst for the degradation of spent wash and Jakofix red dye under natural sunlight. The degradation of coloured compounds in spent wash was monitored by gel permeation chromatography (GPC), which showed the degradation of high-molecular-weight compounds into low-molecular-weight fractions. The catalyst decomposed 90% of Jakofix red dye (HE 8BN) in 3.5 h and 65% of spent wash in 5 h under irradiation with natural sunlight, whereas Degussa P-25 TiO2 was only able to decompose 35% of the dye and 20% of spent wash under identical reaction conditions. A cycling stability test showed the high stability and reusability of the photocatalyst for degradation reactions, with a recovery of around 94-96%.