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Highlights: [•] A modified polyacrylamide gel route is used to synthesize novel light emission materials AlFeO3. [•] Phase transformation process of AlFeO3 have been studied. [•] Luminescence mechanisms of AlFeO3 have been discussed. [ABSTRACT FROM AUTHOR]

A modified polyacrylamide gel route is applied to synthesize SnO2 nanoparticles. High-quality SnO2 nanoparticles with a uniform size are prepared using different chelating agents. The average particle size of the samples is found to depend on the choice of the chelating agent. The photoluminescence spectrum detected at λex = 230 nm shows a new peak located at 740 nm due to the surface defect level distributed at the nanoparticle boundaries. [ABSTRACT FROM AUTHOR]

Abstract: A modified polyacrylamide gel route is used to synthesize porous monolithic α-alumina. X-ray powder diffraction analysis indicates that the as-prepared samples are rhombohedral α-alumina phase, suggesting that high-purity α-alumina can be prepared by using different chelating agents and sintering at about 1150°C. The scanning electron microscopic images show that the macropore size of the α-alumina samples is related to the chelating agent. The photoluminescence spectra show that a major emission band around 365nm and a weaker side band located at 330nm are observed when the excitation wavelength is 228nm. Interestingly, the intensity of emission peak at 365nm decreases with the decreasing pore size. The pore-forming and luminescence mechanisms of porous alumina have been discussed based on the experimental results. [Copyright &y& Elsevier]

Two-dimensional (2D) materials with a high solar to hydrogen (STH) conversion are in high demand due to the escalating energy crisis and environmental degradation. The STH efficiency is strongly correlated with the charge carrier separation, which can be improved by the inside electric dipole. Herein, the water-splitting capabilities of single-layer (SL) GaInS 3 are explored by employing first-principles calculations. Theoretical outcomes reveal that SL GaInS 3 exhibits a large intrinsic electric dipole and has a thermally stable structure at 300 K. SL GaInS 3 displays a direct bandgap of 1.83 eV, as well as suitable band edges and abundant visible absorption (105 cm−1) for solar-driven water-splitting. The electronic structure and carrier mobility calculations demonstrate the high separation efficiency of charge carriers, which is strongly affirmed by the quite long carrier lifetime of 8.26 ns. The overpotential analysis of charge carriers suggests that the oxygen generation of SL GaInS 3 can be accomplished without a cocatalyst, while hydrogen generation can be completed with the aid of cocatalysts. The STH efficiency of SL GaInS 3 reaches up to 16.8%, apparently surpassing the commercial standard (10%). In brief, the high STH and long carrier lifetime promise the possible application of SL GaInS 3 for solar water splitting. What's more, this work provides straight evidence that 2D photocatalysts with inside dipoles exhibit a long carrier lifetime. • Single-layer GaInS 3 has appropriate and edges and abundant visible absorption for solar water-splitting. • The electronic structure confirms the high charge carrier separation efficiency in single-layer GaInS 3. • The quite long carrier lifetime of 8.26 ns in single-layer GaInS 3 is predicted. • The solar to hydrogen conversion of single-layer GaInS 3 reaches up to 16.8%. [ABSTRACT FROM AUTHOR]

Hydrogen energy from solar water-splitting is known as an ideal method with which to address the energy crisis and global environmental pollution. Herein, the first-principles calculations are carried out to study the photocatalytic water-splitting performance of single-layer GaInSe3 under biaxial strains from −2% to +2%. Calculations reveal that single-layer GaInSe3 under various biaxial strains has electronic bandgaps ranging from 1.11 to 1.28 eV under biaxial strain from −2% to +2%, as well as a completely separated valence band maximum and conduction band minimum. Meanwhile, the appropriate band edges for water-splitting and visible optical absorption up to ~3 × 105 cm−1 are obtained under biaxial strains from −2% to 0%. More impressively, the solar conversion efficiency of single-layer GaInSe3 under biaxial strains from −2% to 0% reaches over 30%. The OER of unstrained single-layer GaInSe3 can proceed without co-catalysts. These demonstrate that single-layer GaInSe3 is a viable material for solar water-splitting. [ABSTRACT FROM AUTHOR]

Three ZnAl2O4 samples were prepared via a modified polyacrylamide gel method using a citric acid solution with different aluminum salt starting materials, including AlCl3∙6H2O, Al2(SO4)3∙18H2O, and Al(NO3)3∙9H2O under identical conditions. The influence of different aluminum salts on the morphologies, phase purity, and optical and fluorescence properties of the as-prepared ZnAl2O4 nanoparticles were studied. The experimental results demonstrate that the phase purity, particle size, morphology, and optical and fluorescence properties of ZnAl2O4 nanoparticles can be manipulated by the use of different aluminum salts as starting materials. The energy bandgap (Eg) values of ZnAl2O4 nanoparticles increase with a decrease in particle size. The fluorescence spectra show that a major blue emission band around 400 nm and two weaker side bands located at 410 and 445 nm are observed when the excitation wavelength is 325 nm. The ZnAl2O4 nanoparticles prepared from Al(NO3)3∙9H2O exhibit the largest emission intensity among the three ZnAl2O4 samples, followed in turn by the ZnAl2O4 nanoparticles prepared from Al2(SO4)3∙18H2O and AlCl3∙6H2O. These differences are attributed to combinational changes in Eg and the defect types of the ZnAl2O4 nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract: A series of new N-substituted 1H-dibenzo[a,c]carbazole derivatives were synthesized from dehydroabietic acid, and their structures were characterized by IR, 1H NMR and HRMS spectral data. All compounds were evaluated for their antibacterial and antifungal activities against four bacteria (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens) and three fungi (Candida albicans, Candida tropicalis and Aspergillus niger) by serial dilution technique. Some of the synthesized compounds displayed pronounced antimicrobial activity against tested strains with low MIC values ranging from 0.9 to 15.6μg/ml. Among them, compounds 6j and 6r exhibited potent inhibitory activity comparable to reference drugs amikacin and ketoconazole. [Copyright &y& Elsevier]

A series of new 1,3,4‐oxadiazin‐5(6H)‐one derivatives (6a–n) of dehydroabietic acid were designed and synthesized as potential antimicrobial and antitumor agents. Their structures were characterized by IR, 1H NMR, 13C NMR, MS, and elemental analyses. All the title compounds were evaluated for their antimicrobial activity against four bacterial and three fungal strains using the serial dilution method. Among them, compound 6e showed the highest antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) value of 1.9 μg/mL. In addition, the in vitro cytotoxic activities of the title compounds were also assayed against three human carcinoma cell lines (MCF‐7, SMMC‐7721, and HeLa) through the MTT colorimetric method. As a result, compounds 6b, 6g, 6k, and 6m exhibited significant inhibition against at least one cell line with IC50 values below 10 μM. Compound 6m was especially found to be the most potent derivative with IC50 values of 2.26 ± 0.23, 0.97 ± 0.11, and 1.89 ± 0.31 μM against MCF‐7, SMMC‐7721, and HeLa cells, respectively, comparable to positive control etoposide. [ABSTRACT FROM AUTHOR]

A series of new quinoline derivatives of ursolic acid were designed and synthesized in an attempt to develop potential anticancer agents. The structures of these compounds were identified by 1 H NMR, 13 C NMR, IR and ESI-MS spectra analysis. The target compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines (MDA-MB-231, Hela and SMMC-7721). From the results, compounds 3a – d displayed significant antitumor activity against three cancer cell lines. Especially, compound 3b was found to be the most potent derivative with IC 50 values of 0.61 ± 0.07, 0.36 ± 0.05, 12.49 ± 0.08 μM against MDA-MB-231, HeLa and SMMC-7721 cells, respectively, stronger than positive control etoposide. Furthermore, the Annexin V-FITC/PI dual staining assay revealed that compound 3b could significantly induce the apoptosis of MDA-MB-231 cells in a dose-dependent manner. The cell cycle analysis also indicated that compound 3b could cause cell cycle arrest of MDA-MB-231 cells at G0/G1 phase. [ABSTRACT FROM AUTHOR]

A series of new 1 H -benzo[ d ]imidazole derivatives of dehydroabietic acid were designed and synthesized as potent antitumor agents. Structures of the target molecules were characterized using MS, IR, 1 H NMR, 13 C NMR and elemental analyses. In the in vitro cytotoxic assay, most compounds showed significant cytotoxic activities against two hepatocarcinoma cells (SMMC-7721 and HepG2) and reduced cytotoxicity against noncancerous human hepatocyte (LO2). Among them, compound 7b exhibited the best cytotoxicity against SMMC-7721 cells (IC 50 : 0.36 ± 0.13 μM), while 7e was most potent to HepG2 cells (IC 50 : 0.12 ± 0.03 μM). The cell cycle analysis indicated that compound 7b caused cell cycle arrest of SMMC-7721 cells at G2/M phase. Further, compound 7b also induced the apoptosis of SMMC-7721 cells in Annexin V-APC/7-AAD binding assay. [ABSTRACT FROM AUTHOR]

The piezoelectric properties of Janus B 2 XY (X,Y=S, Se, Te) monolayers under zero strain and biaxial strain are investigated using a first principle study. [Display omitted] • The in-plane piezoelectric response of Janus B 2 XY monolayers is comparable with that of the well-known 2D piezoelectric materials. • The piezoelectricity of all B 2 XY monolayers is enhanced by several times when exposed to tensile biaxial strain. • The B 2 STe monolayer could play a role in top/bottom technologies because of considerable out-of-plane piezoelectricity. Herein the piezoelectric properties of two-dimensional (2D) Janus B 2 XY (X, Y = S, Se, Te) monolayers are studied using first principles calculations. Theoretical results reveal that their in-plane piezoelectric response is comparable with that of the well-known 2D piezoelectric materials. Meanwhile, single-layer B 2 STe can play a role in top/bottom technologies because of considerable out-of-plane piezoelectricity. On the other hand, exerting tensile biaxial strain prominently enhance the piezoelectric effect of all B 2 XY monolayers. Their structures are still dynamically and mechanically stable under biaxial strain. In brief, this work defines the B 2 XY monolayers as ultrathin piezoelectric materials, and thus will stimulate related experimental discoveries. [ABSTRACT FROM AUTHOR]

A series of new carbazole derivatives of ursolic acid were designed and synthesized in an attempt to develop potent antimicrobial or antitumor agents. Their structures were confirmed by using IR, HRMS and 1 H NMR analysis. All the synthesized compounds were evaluated for their antimicrobial activity against four bacterial and three fungal strains using serial dilution method. Compounds 3a , 3b , 4a , 4b and 5a – f exhibited significant antibacterial activity against at least one tested bacteria with MIC values of 3.9–15.6 μg/ml. In addition, the in vitro cytotoxicity of these compounds were also assayed against two human tumor cell lines (SMMC-7721 and HepG2) using MTT colorimetric method. From the results, compounds 5a – e and 5h displayed pronounced cytotoxic activity with IC 50 values below 10 μM. Specially, compound 5e was found to be the most potent compound with IC 50 values of 1.08 ± 0.22 and 1.26 ± 0.17 μM against SMMC-7721 and HepG2 cells, respectively, comparable to those of doxorubicin. In addition, compound 5e showed reduced cytotoxicity against noncancerous LO2 cells with IC 50 value of 5.75 ± 0.48 μM. [ABSTRACT FROM AUTHOR]

Highlight: [•] Novel polyvinyl alcohol (PVA)/cellulose nanocrystals (CNs)/silver nanparticles(AgNPs) composites were prepared. [•] CNs/AgNPs were used as bi-functional nanofiller to improve properties of PVA. [•] The mechanical properties and antibacterial activities of PVA were improved significantly by CNs/AgNPs. [ABSTRACT FROM AUTHOR]

• Dehydroabietate-based fluorescent probe for Hg2+ and Fe3+ was synthesized and characterized. • Detection limits of the sensor were 31.0 nM and 31.2 nM for Hg2+ and Fe3+ ions, respectively. • The sensor have a wide pH range for ion detection (5 ~ 12), and a short response time (10 s). • Fluorescent imaging experiments using MCF-7 and SMCC-7721 cell were carried out successfully. A novel dehydroabietic acid-based fluorescent probe (DBH) containing 2,4-diarylbenzimidazole moiety was designed and synthesized, and the compound was characterized by its UV–Vis, FT-IR, 1H NMR, 13C NMR and ESI-MS spectra. DBH could be used for the detection of Fe3+ and Hg2+ through the selective fluorescence quenching in EtOH/H 2 O solution. The probe DBH showed excellent selectivity and sensitivity towards Fe3+ and Hg2+ over other metal ions. The limits of detection were calculated as 3.12 × 10−8 M and 3.10 × 10−8 M, respectively. Especially, DBH have a wide pH range for ion detection (5 ~ 12), and a short response time (10 s). Job's plot method in combination with ESI-MS and FT-IR spectra was used to determine the stoichiometry of DBH -Fe3+/Hg2+ complexes as both 2:1. Moreover, DBH exhibited low cytotoxicity to MCF-7 and SMCC-7721 cells (IC 50 > 100 μM). In the fluorescent cell imaging experiments, DBH could be used as a prominent intracellular probe for the detection of Fe3+ and Hg2+ in living cells. [ABSTRACT FROM AUTHOR]