Journals
2018 EN
Hailong Dou · Shaohui Zheng · Yongping Zhang
The metallic Fe(ii) ion and nonmetallic S codoped g-C 3 N 4 photocatalyst was synthesized through the polymerization of melamine, ferrous chloride and trithiocyanuric acid (TCA) at elevated temperature. The performance of Fe(ii)-S codoped g-C 3 N 4 compounds in RhB photocatalytic degradation was found to increase 5 times. This significant enhancement in catalytic activity is probably related to the enhanced visible light adsorption and the mobility of photoinduced electron/hole pairs, attributable to bandgap narrowing and also lowering in the surface electrostatic potential compared to that of the pure g-C 3 N 4 nanosheets. XRD and XPS results indicate that the Fe species binds with N-atoms to form Fe-N bonds in the state of Fe(ii) ions. Fe(ii) doping increases the specific surface area, and enhances the photoinduced electron/hole pairs illustrated by PL, EIS spectra and transient photocurrent response measurements. The theoretical results show that divalent Fe(ii) ions coordinating in the pore centre among three triazine units form discrete dopant bands and S dopants substituting the N in triazine skeletons excite much stronger delocalized HOMO and LUMO states, facilitating the migration of photogenerated charge carriers, thus enhancing the visible-light driven photocatalytic performance.
Royal Society of Chemistry
Journals
2018 EN
Qin Li · Wenbin Gao · Xiaopeng Zhang
+4 more
Exploring the sensitive and reliable methods for the determination of hydrogen peroxide (H 2 O 2 ) is a crucial issue for the health and environmental challenges. Herein, we demonstrate a facile, but rational and effective solvothermal approach to the synthesis of hierarchical NiO mesoporous nanospheres (NiO-MNS) as an effective non-enzymatic sensor towards the H 2 O 2 detection. Owing to the intercalation and stabilization effect of polyethylene glycol for the Ni(OH) 2 intermediate, the NiO mesoporous nanosphere (NiO-MNS) product is consistent with the low-dimensional nanostructured NiO blocks with large surface area and plentiful mesopores after the calcination treatment. The obtained NiO-MNS sensor presents superior electrochemical performance with a high sensitivity (236.7 μA mM -1 cm -2 ) and low limit of detection (0.62 μM), as well as the good selectivity and reliability for the further application of H 2 O 2 detection. In addition, the unraveling mechanism of the mesopores formation derived from the in situ measurements also offers the valuable guidance for the future design of porous materials for electrochemical devices and other applications.
Royal Society of Chemistry
Journals
2018 EN
Yangliu Xia · Hui-Lin Pang · TongYi Dou
+2 more
The methylation behaviour of 3-BTD in liver S9 from eight different species was characterized with respect to the similarities and differences of their metabolic profiles, catalytic efficacy and inhibitory potency by a known chemical inhibitor.
Royal Society of Chemistry
Journals
2018 EN
Jingru Zhang · Wenzuo Li · Jianbo Cheng
+2 more
MP2/aug-cc-pVTZ calculations have been performed on π-hole triel- and chalcogen-bonded complexes involving a heteroaromatic compound. These complexes are very stable with large interaction energy up to -47 kcal mol -1 . The sp 2 -hybridized nitrogen atom engages in a stronger π-hole bond than the sp-hybridized species although the former has smaller negative electrostatic potential. The sp 2 -hybridized oxygen atom in 1,4-benzoquinone is a weaker electron donor in the π-hole bond than the sp 2 -hybridized nitrogen atom. The π-hole triel bond is stronger than the π-hole chalcogen bond. A clear structural deformation is found for the triel or chalcogen donor molecule in these π-hole-bonded complexes. The triel bond exhibits partially covalent interaction, whereas the chalcogen bond exhibits covalent interaction in the SO 3 complexes of pyrazine and pyridine derivatives with a sp 2 -hybridized nitrogen atom. Intermolecular charge transfer (>0.2 e ) occurs to a considerable extent in these complexes. In ternary complexes involving an aromatic compound, wherein a triel bond and a chalcogen bond coexist, both the interactions are weakened or strengthened when the central aromatic molecule acts as a double Lewis base or plays a dual role of both a base and an acid. Both electrostatic and charge transfer effects have important contributions toward changes in the strength of both interactions.
Royal Society of Chemistry
Journals
2018 EN
Jing Chen · Ying Yuan · Xiaoku Ran
+2 more
Background : Panax ginseng Meyer which has been cultivated and grown naturally in mountainous forests is formally called "Lin-Xia-Shan-Shen" (LXSS), but when cultivated it is called garden ginseng (GG), according to the Chinese Pharmacopoeia (2015 edition). The medicinal value of LXSS is significantly higher than that of GG based on the clinical experience of TCM. This study aimed to evaluate the variety of chemical constituents in LXSS and GG. Methods : 18 LXSS and 6 GG samples were investigated using a UPLC-Q-TOF-MS technique. Results : the contents of 16 metabolites, mainly involved in the biosynthesis of rare ginsenosides (ginsenosides Rg 3 , -Rh 1 , -Rh 2 ), galactose metabolism (myo-inositol), the citric cycle (citric acid and succinic acid), GABA shunt (GABA) and amino metabolism (alanine and aspartic acid), were higher in LXSS than in GG; while 14 metabolites, mainly involved in starch and sucrose metabolism (fructose and sucrose), amino metabolism (tryptophan, proline, dencichine and pyroglutamic acid) and campesterol biosynthesis (campesterol), were lower in LXSS than in GG. For LXSS with different growing years, 5 metabolites showed a tendency to increase dependent on the number of years, and these were related mainly to galactose metabolism (melibiose), the citric cycle (malic acid), fatty acid metabolism (2-hydroxy stearic acid); while 5 metabolites showed a tendency to decrease on ascending the grades, and these were related to sucrose metabolism (fructose and sucrose), fatty acid metabolism (2-hydroxy hexadecanoic acid) and campesterol biosynthesis (campesterol). Conclusion : this proposed analytical method coupled with multivariate analysis is fast, accurate, and reliable for discriminating GG and high cultivation ages of LXSS samples.
Royal Society of Chemistry
Journals
2018 EN
Lijie Qu · Chunling Zhang · Peihong Li
+5 more
Epoxy resin (EP) composites with improved thermal resistance were fabricated. To solve the problem of low thermal resistance derived from phosphazene flame-retardant additives, we designed a system based on flame-retardant microcapsules P(H), with hexaphenoxycyclotriphosphazene as the core and polymethyl methacrylate as the shell. The core-shell structure was characterized and confirmed. The thermal resistance of the cured EP composites containing 1 wt% P(H) microcapsules was improved because of the increased glass transition temperatures. The P(2.75H)/EP composites can reach a limited oxygen index of 30.5% and V-1 rating in UL-94 tests. Heat and gas release rates were reduced during combustion tests. Residual images implied that the P(H) microcapsules may promote the formation of a flame-retardant char layer. Pyrolysis analysis demonstrated that the P(H) microcapsules can decompose in two procedures to produce flame-retardant gas components. Therefore, the flame-retardant mechanism involved the flame inhibition effect in the gas phase, and the charring effect in the condensed phase.
Royal Society of Chemistry
Journals
2018 EN
Yinghai Lyu · Tingting Zhang · Baojuan Dou
+3 more
The process of using biodesulfurization (BDS) to remove sulfur compounds in petroleum has limitations such as low efficiency and low mass transfer. Therefore, it is important to study the combined effects of biosurfactant and the strain on BDS. A thermophilic desulfurization strain, Bacillus sp. Lv13, was isolated from the oilfield and used to produce biosurfactant (BS). The strain was identified as Bacillus licheniformis, a moderate thermophilic bacterium. Its BS was identified as lipopeptide using thin-layer chromatography (TLC), gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR). The emulsification efficiency after 24 h (E24) and critical micelle concentration (CMC) were determined to be 46.93% and 30 mg L−1, respectively. The combined effects of biosurfactant and the strain on BDS was confirmed using the Gibbs assay, GC-MS and BaCl2 test. Results showed that the yield of 2-hydroxybiphenyl (2-HBP) from dibenzothiophene significantly increased after the addition of lipopeptide into the reaction system. This could be illustrated by the stabilization of emulsion, lower CMC value, higher mass transfer rate with the addition of lipopeptide, and the enhancement in the capacity of BDS as well as the catalytic ability of the microbial cell.
Royal Society of Chemistry
Journals
2018 EN
Kui Du · Shizhen Niu · Li Qiao
+4 more
Correction for ‘A highly selective ratiometric fluorescent probe for the cascade detection of Zn 2+ and H 2 PO 4 − and its application in living cell imaging’ by Kui Du et al. , RSC Adv. , 2017, 7 , 40615–40620.
Royal Society of Chemistry
Journals
2018 EN
Maowei Dou · Ying Zhu · Andrey Liyu
+10 more
Multidimensional peptide separations can greatly increase the depth of coverage in proteome profiling. However, a major challenge for multidimensional separations is the requirement of large biological samples, often containing milligram amounts of protein. We have developed nanowell-mediated two-dimensional (2D) reversed-phase nanoflow liquid chromatography (LC) separations for in-depth proteome profiling of low-nanogram samples. Peptides are first separated using high-pH LC and the effluent is concatenated into 4 or 12 nanowells. The contents of each nanowell are reconstituted in LC buffer and collected for subsequent separation and analysis by low-pH nanoLC-MS/MS. The nanowell platform minimizes peptide losses to surfaces in offline 2D LC fractionation, enabling >5800 proteins to be confidently identified from just 50 ng of HeLa digest. Furthermore, in combination with a recently developed nanowell-based sample preparation workflow, we demonstrated deep proteome profiling of >6000 protein groups from small populations of cells, including ∼650 HeLa cells and 10 single human pancreatic islet thin sections (∼1000 cells) from a pre-symptomatic type 1 diabetic donor.
Royal Society of Chemistry
Journals
2018 EN
Xiangnan Dou · Qiang Zhang · Syed Niaz Ali Shah
+3 more
Reactive oxygen species (ROS) generation is of intense interest because of its crucial role in many fields. Here we demonstrate that MoS 2 -QDs exhibit a promising capability for the generation of reactive oxygen species, which leads to enhanced chemiluminescence. We discovered that the unique performance is due to hydroxyl radical activation increasing the active catalytic sites on molybdenum sulphide quantum dots (MoS 2 -QDs). The reactive oxygen species, such as hydroxyl radicals (˙OH), superoxide radicals (˙O 2 - ) and singlet oxygen ( 1 O 2 ) have been efficiently generated from H 2 O 2 solution in alkaline conditions. In particular, the maximum ˙OH yield was enhanced significantly (9.18 times) compared to the Fe(ii)/H 2 O 2 Fenton system under neutral conditions. These findings not only enrich our understanding of the fascinating performance of MoS 2 QDs, but also provide a new pathway for ROS generation in all kinds of pH environment.
Royal Society of Chemistry