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Layered Aurivillius compound Bi5Ti3CrO15 has been synthesized by a hydrothermal method for the application as a photocatalyst to liberate hydrogen from water. Bi5Ti3CrO15 owns a narrow band gap (Eg ~2.46 eV) and shows stable photocatalytic activity under both full range (λ ≥250 nm) and visible light illumination (λ ≥420 nm). A short hydrothermal reaction time is critical to achieve high photocatalytic activity as defects such as Cr6+ and Bi5+ can be avoided. An AQE as high as 3.66% at 420 nm ± 20 nm has been recorded, warranting promising application in the field of solar energy conversions. DFT calculation reveals the important role of Cr3+cations for visible light sensitivity of Bi5Ti3CrO15.

Liposomes are among the most extensively applied drug carriers due to their excellent biocompatibility, controllable size and ease of modification. In the present study, we prepared untargeted liposomes (LP) and targeting liposomes modified with Arg-Gly-Asp (RGD-LP), and Doxorubicin Hydrochloride (DOX) or fluorescent probe was loaded. RGD-LP/DOX was identified to be uniformly spherical in size 131.2 ± 2.7 nm. Based on flow cytometry analysis and the confocal laser scanning microscopy, RGD-LP had a higher uptake into HRT-18 colorectal cancer cells than LP. Further

Mucoromycota are diverse in microbial oils, but oil-related studies have long been confined to a few particular genera and species. This study used the Sherlock Microbial Identification System to determine fatty acid compositions and consequently discover potential resources from 669 strains representing 133 species in 28 genera in 11 families from the core mucoromycotan orders Mortierellales, Mucorales, and Umbelopsidales. Results showed that 34% of strains, 50% of species, and 46% of genera were oleaginous. Eleven genera were proposed as oleaginous taxa for the first time. Among them, Backusella was highlighted in accumulating as high as 59.08 ± 2.24% of oils. Twenty-five and 50 strains were screened as potential high-yield fungi for oils and high-value fatty acids respectively. Pilaira produced the most C18:2, while Rhizopus and Thamnostylum produced the most C18:3. Only strains of Mortierella produced C20:4; Mo. amoeboidea CGMCC 3.15949 yielded 58.00% ± 1.15% of C20:4, which suggests it is an excellent source of C20:4. This study suggests for the first time that the bulk of Mucoromycota is rich in lipids. More genera and species were discovered herein as oil-producing resources. These findings serve as a foundation for further research on microbial oil production.

Sr2TiO4 and NaLaTiO4 are structural congeners with K2NiF4-type layered perovskite structure. However, nitrogen doping results in distinct modifications to their visible light absorption. Na/La orde...

Traditionally, vessel air emissions are monitored onboard vessels or at fixed points at sea. These methods ineffectively meet the needs of monitoring pollution from vessels travelling. Unmanned aerial vehicles (UAVs) equipped with pollution monitoring sensors are becoming a research focus. However, due to battery capacity constraints, the monitoring scope of UAVs is still not optimal. Thus, using a ship (such as a patrol ship) as a UAV mobile supply base can overcome battery limitations and increase monitoring coverage. This paper investigates the joint routing and scheduling problem of ship-deployed multiple UAVs (SDMU) for the monitoring of pollution from vessels.The artificial bee colony (ABC) algorithm based on simulated annealing is employed to minimize the total monitoring time. The model and solution algorithm are verified by real-time dynamic vessel data from Tianjin Port.

In this study, we comprehensively explored graphene oxide (GO)-induced systemic immune responses and interference with hematopoiesis in mice upon GO intravenous injection. In the liver and spleen, GO led to alterations in immune components at different time points. GO exposure showed an effect on the populations of different types of hepatic macrophages. In the liver, the populations of macrophages mainly affected by GO including Kupffer cells and monocyte-derived macrophages. Stimulated hepatic inflammation led to the infiltration of platelets from the circulation into the liver and decreased peripheral platelets population at day 1. Interestingly, a decreased platelet population was observed on day 7 in the spleen. GO also led to accelerated hematopoiesis in the spleen. Therefore, the possible forced generation of more platelets and the release of mature platelets from the spleen contributed to the increased circulating platelet count on day 7. Therefore, although GO showed a low potential to induce severe inflammation in the liver and spleen, it disrupted hematopoiesis in the spleen, which contributed to fluctuations in circulating platelet counts. The interaction of GO with the immune system warrants comprehensive study for gaining better understanding.

A new species of Alternaria causing leaf spots on the rubber tree (Hevea brasiliensis) in Yunnan, China, was isolated, examined, and illustrated. Morphologically, it belongs to the section Porri of Alternaria, which produces relatively large conidia and a simple or branched, filamentous long beak. It is, however, characterized by conidiophores gradually enlarging near the apex into a clavate conidiogenous cell and long ellipsoid to obclavate, smooth-walled conidia with a long filamentous beak. Molecular phylogenetic analyses based on ITS rDNA, GAPDH, and TEF1-alpha sequences demonstrate that the phytopathogen falls in the clade of the section Porri, being most closely related to A. sidae, A. sennae, A. deseriticola, A. cyamopsidis, A. rostellata, A. nitrimali, A. crassa, and A. thunbergiae.

Constituting solid solutions has been an appealing means to gain control over various physicochemical properties. In this work, we synthesized a series of SrTiO3-BiFeO3 solid solutions and systematically explored their structural, optical and photocatalytic properties. Our results show that all solid solutions crystallize in a primitive cubic structure and their band gap values can be easily tuned by adjusting molar ratios between SrTiO3 and BiFeO3. Photocatalytic hydrogen production under both full range and visible light irradiation is greatly improved after forming solid solutions. The highest hydrogen production rate obtained is ∼180 μmol/h under full range irradiation (λ ≥ 250 nm) and ∼4.2 μmol/h under visible light irradiation (λ ≥ 400 nm), corresponding to apparent quantum efficiency ∼2.28% and ∼0.10%, respectively. The activity is found to be strongly influenced by surface area and light absorption. Theoretical calculation suggests that Fe contributes to the formation of spin-polarized bands in the middle of original band gap and is responsible for the band gap reduction and visible light photocatalytic activity.

Constituting solid solutions for prototype perovskite compound SrTiO3 offers appealing means to tailor the optical and photocatalytic properties of this wide band gap semiconductor. Here we successfully synthesized a series of Sr1-xBixTi1-xFexO3 (0 ≤ x ≤ 0.5) solid solutions via hydrothermal method. Their crystal structures, surface nature and other physicochemical properties were systematically explored. Our results show that a large portion of BiFeO3 (up to 50%) can be incorporated into the structure SrTiO3 without symmetry degradation from cubic. A number of important factors such as microstructures, light absorbance and surface hydrophilicity are all strongly correlated with Bi/Fe content in the solid solutions. Photocatalytic performance was greatly improved after formation of solid solutions and high activity normally occurs in samples with large surface area, high crystallinity as well as absence of Bi (V) species. The highest activity belongs to sample Sr0.6Bi0.4Ti0.6Fe0.4O3 with photocatalytic hydrogen production rate ∼50 μmol/h under full range irradiation and ∼5 μmol/h under visible light irradiation, corresponding to apparent quantum efficiency ∼0.63% and 0.11%, respectively. Theoretical calculation reveals the critical role of Fe in constituting spin-polarized bands inside the intrinsic band gap of SrTiO3, therefore is responsible for band gap reduction and visible light activities. This work highlights the benefits of forming solid solutions in the design and development of efficient photocatalysts.

Strong visible light absorption and high charge mobility are desirable properties for an efficient photocatalyst, yet they are hard to be realized simultaneously in a single semiconductor compound. In this work, we demonstrate that these properties coexist in homologous compounds ZnnIn2O3+n (n = 4, 5, and 7) with a peculiar layered structure that combines optical active segment and electrical conductive segment together. Their enhanced visible light absorption originates from tetrahedrally or trigonal-bipyramidally coordinated In atoms in Zn(In)O4(5) layers which enable p–d hybridization between In 4d and O 2p orbitals so that valence band minimum (VBM) is uplifted with a reduced band gap. Theoretical calculations reveal their anisotropic features in charge transport and functionality of different constituent segments, i.e., Zn(In)O4(5) layers and InO6 layers as being for charge generation and charge collection, respectively. Efficient photocatalytic hydrogen evolution was observed in these compounds unde...

Surface properties play a vital role in many heterogeneous catalytic reactions, particularly in photocatalytic water splitting, where photo-generated electron and holes must migrate to and be transferred at the very top surface of a photocatalyst. Here, we carried out a detailed investigation on the role of surface composition towards photocatalytic hydrogen production of perovskite-based materials, namely, Cr-doped and La/Cr-codoped SrTiO3. Our findings showed that a depletion of B site cations occurred at the surface of these high-temperature annealed samples and a severe diminishing of B site cations took place after introducing La cations at the A site. Although the presence of La helps to improve surface alkalinity and inhibit the formation of detrimental Cr6+ species, La/Cr-codoped sample showed a poor photocatalytic activity. Such a correlation between surface composition and photocatalytic activity suggests that surface tailoring or composition control is highly necessary in the design and development of these perovskite-based photocatalysts. Since surface rearrangements can be kinetically hindered at low temperatures, low temperature synthetic methods are therefore strongly preferred during the synthesis of these perovskite-based photocatalysts.

The crystal structure of photocatalysts generally plays a pivotal role in controlling their electronic structure as well as catalytic performance. In this work, a series of double perovskite compounds A2InTaO6 (A = Sr or Ba) and their Ni doped counterparts were investigated with the aim of understanding how doping and structural modification will affect their photocatalytic activity. Our results show that Ni doping is effective in improving the optical absorption of these wide band gap semiconductors and accommodating the Sr cation in the A sites leads to severe structural distortion, i.e. the In(Ni)-O-Ta bond angle deviates largely from 180°. A better photocatalytic performance was observed for samples with Ni doping and Ba in the A sites. The best photocatalytic hydrogen production rate recorded was ∼293.6 μmol h(-1) for Ba2In0.9Ni0.1TaO6 under full range irradiation, corresponding to an apparent quantum efficiency of 2.75%. DFT calculations reveal the role of Ni doping by forming additional spin-polarized bands inside the intrinsic band gap of the native perovskite. The better photocatalytic activity of Ba2In0.9Ni0.1TaO6 can then be understood as a result of a reduced band gap as well as a linear In(Ni)-O-Ta bond arrangement that is favorable for the strong metal-oxygen-metal interactions.

Doping has generally been served as one of the most efficient strategies for the improvement of wide band gap semiconductor photocatalysts. However, atomic arrangements of doped elements in the host crystal structure have often been overlooked, particularly during the investigation and evaluation of dopant functionality. It is known that electronic structures of a semiconductor are profoundly controlled by atomic occupancies in different crystallographic positions. Knowledge about dopant accommodations in the crystal structure and their influence towards photocatalytic performance is highly desired. Here, we investigated four compositional and structural relevant compounds CrNbO4, CrTaO4, Sr2CrNbO6 and Sr2CrTaO6 with the aim to study the effects of cation ordering/disordering upon their photocatalytic activity. Our results showed that ordered cations, namely Cr and Nb/Ta, are detrimental to the photocatalytic performance. Theoretical calculations indicate that cation ordering would enlarge the band gap and inhibit charge transfer between Cr and Nb/Ta. Our findings imply that ordered dopants in photocatalytic materials would severely offset the benefits of doping and might be a reason for the decreased activity at high doping levels often encountered.

Photocatalytic water splitting is an appealing process for solar energy conversions yet it is often limited by the slow oxidation of water to oxygen half-reaction. Here we performed an investigation on N-doped Sr4Nb2O9 as a water oxidation photocatalyst. Our results show that N doping is an effective approach to improve the visible-light response of Sr4Nb2O9. Efficient photocatalytic oxygen production was observed after N doping, and the highest production rate of ∼27 μmol h−1 under visible-light irradiation corresponds to an apparent quantum efficiency of ∼0.31 %. Clear anodic photocurrent can be generated under visible-light illumination, and the flat-band potential was determined to be ∼−1.25 V vs. Ag/AgCl at pH 7. Theoretical calculations reveal that N doping introduces additional valence bands and is responsible for the visible-light response. Variations in light absorption and photo-oxidation performance can be controlled by modifying these valence band positions using different nitridation temperatures.

Separation of photo-generated charges has played a crucial role in controlling the actual performance of a photocatalytic system. Here we have successfully fabricated g-C3N4/TiO2-B nanowire/tube heterostructures through facile urea degradation reactions. Owing to the effective separation of photo-generated charges associated with the type-II band alignment and intimate interfacial contacts between g-C3N4 and TiO2-B nanowires/tubes, such heterostructures demonstrate an improved photocatalytic activity over individual moieties. Synthetic conditions such as hydrothermal temperatures for the preparation of TiO2-B and the weight ratio of TiO2-B to urea were systematically investigated. A high crystallinity of TiO2-B as well as the proper growth of g-C3N4 on its surface are critical factors for a better performance. Our simple synthetic method and the prolonged lifetime of photo-generated charges signify the importance of type-II heterostructures in the photocatalytic applications.

Ultrathin nitrogen-doped perovskite nanosheets LaTa2O6.77N0.15– have been fabricated by exfoliating Dion–Jacobson-type layered perovskite RbLaTa2O6.77N0.15. These nanosheets demonstrate superior photocatalytic activities for water splitting into hydrogen and oxygen and remain active with photon wavelengths as far as 600 nm. Their apparent quantum efficiency under visible-light illumination (λ ≥ 420 nm) approaches 1.29% and 3.27% for photocatalytic hydrogen and oxygen production, being almost 4-fold and 8-fold higher than bulk RbLaTa2O6.77N0.15. Their outstanding performance likely stems from their tiny thickness (single perovskite slab) that essentially removes bulk charge diffusion steps and extends the lifetime of photogenerated charges. Theoretical calculations reveal a peculiar 2D charge transportation phenomenon in RbLaTa2O6.77N0.15; thus, exfoliating RbLaTa2O6.77N0.15 into LaTa2O6.77N0.15– nanosheets has limited impact on charge transportation properties but significantly enhances the surface areas ...

Strong visible light absorption and high charge mobility are desirable properties for an efficient photocatalyst, yet they are hard to be realized simultaneously in a single semiconductor compound. In this work, we demonstrate that these properties coexist in homologous compounds Zn

Wurtzite solid solutions between GaN and ZnO highlight an intriguing paradigm for water splitting into hydrogen and oxygen using solar energy. However, large composition discrepancy often occurs inside the compound owing to the volatile nature of Zn, thereby prescribing rigorous terms on synthetic conditions. Here we demonstrate the merits of constituting quinary Zn-Ga-Ge-N-O solid solutions by introducing Ge into the wurtzite framework. The presence of Ge not only mitigates the vaporization of Zn but also strongly promotes particle crystallization. Synthetic details for these quinary compounds were systematically explored and their photocatalytic properties were thoroughly investigated. Proper starting molar ratios of Zn/Ga/Ge are of primary importance for single phase formation, high particle crystallinity and good photocatalytic performance. Efficient photocatalytic hydrogen and oxygen production from water were achieved for these quinary solid solutions which is strongly correlated with Ge content in the structure. Apparent quantum efficiency for optimized sample approaches 1.01% for hydrogen production and 1.14% for oxygen production. Theoretical calculation reveals the critical role of Zn for the band gap reduction in these solid solutions and their superior photocatalytic acitivity can be understood by the preservation of Zn in the structure as well as a good crystallinity after introducing Ge.

Modification of prototype perovskite compound SrTiO3 by introducing foreign elements has been an appealing means to endow this wide band gap semiconductor with visible light responses. Here we systematically investigated a series of Sr1-xBixTi1-xCrxO3 solid solution compounds prepared by two different synthetic routes, namely, solid state reactions and the hydrothermal method. Their crystal structures as well as other physicochemical properties were explored. Our results showed that a number of important factors such as microstructures, crystallinity, light absorbance and surface compositions etc. are all strongly correlated with the synthetic methods used. The hydrothermal method is generally helpful for morphology controls as well as avoiding Cr(6+) defects and Sr segregation at the surface, thereby contributing to a high photocatalytic activity. Better performance normally occurs in samples with a high crystallinity and free of defects like Bi(5+). Theoretical calculations suggest that Cr plays an important role in band gap reduction and photocatalytic reactions, while Bi only acts as a constituent cation for the perovskite structure and does not significantly alter the electronic structures near the Fermi level. Our findings have revealed how synthetic routes are relevant to the final photocatalytic properties of a compound, and therefore comparisons among various photocatalysts have to include concerns about their preparation history.

Layered semiconductor photocatalysts have been found to exhibit promising performance levels, probably linked to their interlayer framework that facilitates separation of charge carriers and the reduction/oxidation reactions. Layered titanates, however, generally demonstrate activities under UV irradiation, and therein lies the strong desire to extend their activity into the visible light region. Here, we investigated a series of layered perovskite by doping Sr2TiO4 with Cr and/or La in the hope to improve their visible light responses. Their crystal structures and other physicochemical properties were systematically explored. Our results show that La and Cr can be successfully accommodated in the layered structure and Cr is an efficient dopant for the extension of visible light absorbance. Much enhanced photocatalytic hydrogen evolution was observed after doping and was found to be composition-dependent. The highest hydrogen production rate approaches 97.7 μmol/h for Sr2Ti0.95Cr0.05O4-δ under full range irradiation (λ ≥ 250 nm) and 17 μmol/h for Sr2Ti0.9Cr0.1O4-δ under visible light irradiation (λ ≥ 400 nm), corresponding to an apparent quantum efficiency of 0.16% and 0.05%, respectively. Theoretical calculation reveals that the improved optical and photocatalytic properties are owing to a newly formed spin-polarized valence band from Cr 3d orbitals. The decreased unit cell parameters, reduced band gaps as well as anisotropic properties of layered architectures are likely the reasons for a better activity. Nevertheless, instability of these compounds in the presence of moisture and CO2 was also noticed, suggesting that protective atmospheres are needed for the storage of these photocatalysts.