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Double network gel with sodium alginate (SA) and starch was used as the matrix to immobilize indium sulfide (In2S3) in situ by microwave-assistant solution method. The coordination between In3+ and hydroxy or carboxyl in SA/starch contributed to the formation of binding sites followed by the hydrolysis of sulfur sources to form In2S3. The morphology and loadage of In2S3 presented the correlation with microwave reaction time, resulting in different thermostabilities, surface properties and photoelectric properties. The composite film with In2S3 synthesized for 40 min (In2S3 film-40) displayed extremely rapid photodegradation of rhodamine (RhB) based on the synergistic effect of the adsorption and decomposition. The excellent adsorption originated from not only the maximum hydrophilia of the matrix but also the maximum content of In2S3 with uniform pore distribution. Furthermore, the presence of In2S3-40 particles (In2S3 particle-40) with high content in the composite film increased the number of active specifies, especially its high electron-hole separation ability contributed to the rapid oxidation of RhB. The optimal photocatalysis was obtained in the acidic solution with pH of 3 and moderate dye concentration of 60 mg/L. Finally, In2S3 film-40 displayed the availability of multiple reusability with an unchangeable structure. Highlights: In2S3 composite film was synthesized with in situ microwave reaction on double network gel. The loadage of In2S3 depended on microwave reaction time. The photocatalysis of In2S3 film was related to the synergistic effect of adsorption and decomposition. The excellent adsorption was from the mutual interaction between matrix and photocatalysts. The rapid decomposition was due to the presence of photocatalysts with high charge separation. [ABSTRACT FROM AUTHOR]

In this paper, CdS nanorings synthesized by a facile hydrazine-induced microwave method for the photodegradation of pollutants were reported for the first time. Different reaction method, microwave power, the category and dosage of pH regulating reagent, reaction temperature and reaction time were investigated. The formation of CdS nanorings from the self-assembly of nanoparticles was attributed to the coordination of hydrazine producing the dipole–dipole interaction among the uniform nanoparticles prepared by microwave method. The crystal phase, composition, morphology and surface property of CdS nanorings were characterized. The results showed that 100 nm-sized wurtzite CdS nanorings generated with the self-assembly of 5–8 nm nanoparticles, which presented mesoporous structures. To study the influence of ring-like structures on the photocatalysis, the photodegradation of rhodamine B (RhB) with CdS nanorings and nanoparticles was compared. The results showed that, CdS nanorings displayed higher photodegradation efficiency, which were originated from more favorable band edge potential and effective electron–hole separation producing more superoxide radical and holes as active specifies. The photodegradation path of RhB contained the process of the demethylation, the decarboxylation process, the chromophore cleavage and ring-open reactions. Finally, the available photodegradation of multiple pollutants and reusability of CdS nanorings were carried out. [ABSTRACT FROM AUTHOR]

In this paper, two morphologies of crystalline Sb2S3 as dumbbell-like Sb2S3 and bundle-like Sb2S3 were synthesized by different phase-transformation of amorphous-to-crystalline, respectively. Different factors such as the variation of the solvent ratio, the surfactant, reaction temperature and reaction time were observed to obtain the key factor influencing the morphology. The bandgap of two Sb2S3 was obtained by diffused reflectance spectra and cyclic voltammetry. The charge separation was characterized by fluorescence spectrum, linear sweep voltammetry, transient photocurrent-time curve and electrochemical impedance spectrum. The results showed that bundle-like Sb2S3 had slightly higher light-harvesting and obvious higher charge separation ability, which was beneficial to the photodegradation of malachite green (MG). The photodegrdation path of MG implied the intermediates generated by bundle-like Sb2S3 were more easily decomposed to the small molecules. Bundle-like Sb2S3 displayed excellent reusability in the photodegradation of MG. Superoxide anion radical (·O2−) and hydroxyl radical (·OH) as the active species contributed to the photodegradation reaction. [ABSTRACT FROM AUTHOR]

In attempts to evaluate the environmental risk produced by plastic markets, the levels and congener profiles of phthalate esters (PAEs) in soil, vegetable, and sediment samples collected from the plastic market in China, where numerous plastic products are exchanged every year, were investigated. The concentrations of ∑22PAEs ranged from 2131 to 27,805 ng g−1 in agricultural soils, from 8023 to 37,556 ng g−1 in vegetables and from 9031 to 87,329 ng g−1 in sediments. The predominant PAE pollutants were di-(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), di-isobutyl phthalate (DiBP), and dibenzyl phthalate (DBzP). The mean percentages of the predominant PAEs in the soil, vegetable, and sediment samples accounted for 98.4%, 97.3%, and 99.5% of the total PAEs, respectively. The concentrations of PAEs at the sites around the plastic market were significantly higher than those at other pollution sites, such as sites contaminated by agricultural plastic film, electronic waste (e-waste) recycling sites, and industrial parks, indicating that the plastic market was an important pollution source. The DEHP concentrations in the soils, vegetables, and sediments and the DnBP concentrations in the vegetables all exceeded the environmental risk levels (ERL) or the environmental allowable levels (EAL), indicating that the plastic market posed potential environmental risks. [ABSTRACT FROM AUTHOR]

The emissions of brominated flame retardants (BFRs) from consumer products have been considered the major to the ubiquitous occurrence of contaminants in indoor environments. Direct contact with dust covering the surface of source materials in a real environment could introduce significant uncertainty. This study investigated the effects of dust coverage on the emissions of four BFRs, including 1, 2, 5, 6, 9, and 10-hexabromocyclododecane (HBCD), bis(2-ethyl-1-hexyl) tetrabromophthalate (BEHTBP), tetrabromobisphenol A (TBBPA), and hexabromobenzene (HBBZ), from decorative laminate, cotton sound insulation, PVC floor, and carpet. Direct contact with dust was confirmed to increase the total emissions by 30.8-98.1% compared with the emissions in the non-dust group. The emissions of HBCD, TBBPA, and HBBZ from cotton sound insulation were obviously enhanced by dust with smaller particles but did not linearly increase along with the dust amounts. Thus, these findings have practical implications in that the frequent removal of dust could be important to minimize the exposure risk from indoor emissions of BFRs. [ABSTRACT FROM AUTHOR]

Though black silicon has excellent anti-reflectance property, its passivation is one of the main technical bottlenecks due to its large specific surface area. In this paper, multicrystalline black silicon is fabricated by metal assisted chemical etching, and is rebuilt in low concentration alkali solution. Different solution pre-treatment is followed to make surface modification on black silicon before Al2O3 passivation by atomic layer deposition. HNO3 and H2SO4 + H2O2 solution pre-treatment makes the silicon surface become hydrophilic, with contact angle decrease from 117.28° to about 30°. It is demonstrated that when the pre-treatment solution is nitric acid, formed ultrathin SiOx layer between Al2O3 layer and black silicon is found to increase effective carrier lifetime to 72.64 µs, which is obviously higher than that of the unpassivated black silicon. The passivation stacks of SiOx/Al2O3 are proved to be effective double layers for nanoscaled multicrystalline silicon surface. [ABSTRACT FROM AUTHOR]

In this paper, we report passivation properties of inverted pyramidal nanostructure based multi-crystalline silicon (mc-Si) by Al2O3 films with spin-coating method. Precursors AlCl3 and Al(acac)3 for Al2O3 films were chosen for comparison. Al2O3/SiOx stacks were found to be able to passivate the nanostructured surface well. With the number of spin-coating up to five, the Al2O3 films could conformally attach the nanostructure. The weighted average reflectance values (ranging from 400-900 nm) of the passivated silicon surface could be reduced to 10.74% (AlCl3) and 11.12% (Al(acac)3), and the effective carrier lifetime could reach 7.84 and 16.98 μs, respectively. This work presented a potential process to fabricate low cost high efficiency mc-Si solar cells. [ABSTRACT FROM AUTHOR]