ISSN 0253-2778

CN 34-1054/N

2020 Vol. 50, No. 11

Display Method:
Review Article
Photocatalytic methane conversion over metal oxides: Fundamentals, achievements, and challenges
Jiang Wenbin, Low Jingxiang, Qiu Chang, Long Ran, Xiong Yujie
2020, 50(11): 1361-1382. doi: 10.3969/j.issn.0253-2778.2020.11.001
With the rapid development of combustible ice and shale gas mining technology, the reserve of methane (CH4) has been growing abundant. Therefore, there is a paradigm shift, where CH4 is not seen only as a hydrocarbon fuel, but also as carbon feedstocks for synthesizing various value-added chemicals. However, the conventional CH4 conversion technology, especially steam reforming of methane, normally requires extensive energy input due to the extremely stable bonding of CH4. To this end, photocatalysis, which can break the thermodynamic barrier of CH4 conversion, has been known as a promising candidate for reaching large-scale CH4 conversion under ambient condition. In the photocatalytic CH4 conversion researches, metal oxides have been extensively investigated mainly due to their high oxidation capability. In this review, a discussion is first given on the fundamentals of CH4 conversion and the advantages of metal oxides in such a reaction. Then the development of metal oxides-based photocatalysts in various CH4 conversion reactions is reviewed, including total oxidation of methane (TOM), partial oxidation of methane (POM), dry-reforming of methane (DRM), non-oxidative coupling of methane (NOCM), lattice oxygen mediated oxidative coupling of methane (LOCM) and so on. Finally, the opportunities of metal oxides-based photocatalytic CH4 conversion along with the challenges are summarized.
Recent achievements in solution processed antimony selenosulfide solar cells
Jiang Chenhui, Tang Rongfeng, Zhu Changfei, Chen Tao
2020, 50(11): 1383-1393. doi: 10.3969/j.issn.0253-2778.2020.11.002
Antimony selenosulfide, Sb2(S,Se)3, displays superior optoelectronic properties such as strong absorption coefficient and easily tunable bandgap in the range of 1.1~1.7 eV. In terms of practical photovoltaic applications, this semiconductor material is relatively non-toxic, low cost, earth abundant, and stable against moisture and air. Recent investigations have witnessed the rapid development with the power conversion efficiency overcoming the 10% bottleneck in Sb2(S,Se)3 solar cells, demonstrating great potential for further investigations. In this perspective, the structural, crystal and optical properties of Sb2(S,Se)3 are introduced first, and then notable developments are highlighted, primarily in the past three years, in Sb2(S,Se)3 solar cells with film deposition by solution based methods. Finally, some possible strategies are proposed with regard to efficiency improvement.
Research Article
Zinc(II) coordinated lipid for effective and serum-tolerant gene delivery
Zhou Xiaohong, Elbayomi Smaher M, Nie Xuan, Shao Qi, Wang Haili, Wang Fei, You Yezi
2020, 50(11): 1394-1402. doi: 10.3969/j.issn.0253-2778.2020.11.003
In recent years, non-viral vectors, such as cationic polymers and liposomes, have attracted increasing attentions for their applications in gene delivery. However, reduced transfection efficiency inhibits their further use in the presence of serum. Therefore, it is necessary to develop serum-tolerant non-viral gene vectors. Herein, a novel Zn coordinated lipid is synthesized, which self-assembles with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine lipid (DOPE), forming cationic liposome (Zn-DTAc liposome). The experimental results demonstrate that Zn-DTAc liposomes can effectively condense pDNA into nanoparticles, which have high cellular uptake and effective endosomal escape and exhibit efficient gene transfection even in the presence of 50% fetal bovine serum.
Visible light induced Barton decarboxylation free of radical initiators
Wang Jiaxin, Fu Mingchen
2020, 50(11): 1403-1410. doi: 10.3969/j.issn.0253-2778.2020.11.004
Herein, a novel protocol for visible light induced decarboxylation was reported. The method avoids the addition of radical initiators. A series of primary, secondary, and tertiary redox-active esters underwent decarboxylation efficiently, as well as amino acid and peptide derivatives. Many natural products and drug molecules containing carboxyl groups can also be transformed well. The method has mild reaction conditions, wide substrate scope, satisfactory functional group compatibility with good to excellent yields. The preliminary mechanism studies suggested that tris(trimethylsilyl)silane((TMS)3SiH) acts not only as a hydrogen source, but also as an electron donor to form electron donor-acceptor (EDA) complex with redox-active esters, and the reaction involves the radical process.
Mitigating clogging of nESI with nonvolatile buffers that mimic biological samples by induced alternative voltage
Ren Mengting, Huang Guangming
2020, 50(11): 1411-1418. doi: 10.3969/j.issn.0253-2778.2020.11.005
The detection of biological samples requires the adaptation of nanoelectrospray ionization mass spectrometry (nESI-MS) to hasher conditions, such as high concentrations nonvolatile buffers and sub-micrometer scale capillary tips. The two above-mentioned requirements would pose a considerable challenge, clogging, to nESI-MS. Herein, to mitigate the clogging problem, an induced alternative voltage was applied on the nanoemitters, which had inner diameter of less than 1 μm, with the infusion of a high-concentration salt solution, to induce electrospray ionization. The tips lifetime of the modified nESI was found to be 1~2 orders of magnitude longer than that of conventional nESI. The much longer spray time could be attributed to the re-dissolution effect of salt crystals owing to the periodic change in the electric field direction. Meanwhile, the signal of the modified nESI remained stable and sensitive even after a long run (~10 min) for analysis of high-concentration salt solutions. Finally, the mimic extracellular fluid and intracellular fluid were both evaluated, and the result indicated that the application of an induced alternating current voltage can be a widely applicable method to delay clogging during biological sample analysis.
Structures, stabilities and spectra of endohedral mono-metallofullerenes M@C66 (M=Ca, Sr, Ba): A first-principles study
Cui Peng, Zhang Zhuxia, Sharman Edward, Jiang Jun
2020, 50(11): 1419-1430. doi: 10.3969/j.issn.0253-2778.2020.11.006
Structures of many endohedral metallofullerenes (EMF) are still unknown because of their very low production yield, especially for endohedral mono-metallofullerenes below C70. In the present work, we investigated the alkaline earth metal encapsulated mono-metallofullerenes M@C66 (M=Ca, Sr, Ba) theoretically, compounds which have been detected only in mass spectra. The first-principles calculations and statistical thermodynamic analysis indicate that among the C66 isomers considered, the cage C2v(4348)-C66 should be the most likely structure for M@C66, M=Ca, Sr, Ba. These compounds may adopt another cage structure, C2(4466)-C66, at high temperatures. Both M@C2v(4384)-C66 and M@C2(4466)-C66 possess relatively large HOMO-LUMO gaps, and the former also possesses high local aromaticity. Thus it is predicted that M@C2v(4348)-C66—especially Ca@C2v(4348)-C66—could be isolable in future experiments. Moreover, simulated Vis-NIR, IR, Raman and 3C NMR spectra are provided for assisting future experimental characterizations.
An analogical model for tympanometry of the pathological human middle ear
Li Mugeng, Chen Lin
2020, 50(11): 1431-1439. doi: 10.3969/j.issn.0253-2778.2020.11.007
Tympanometry involves measuring the acoustic admittance of the middle ear system as a function of air pressure in the external auditory meatus. Since tympanogram provides a noninvasive and objective evaluation of middle ear functions, it has gained a wide application in the ear, nose, and throat (ENT) clinic. In this study, parameters of the middle ear circuit analog model were manipulated to mimic tympanograms of the ear with a flaccid eardrum and otosclerosis, which were consistent with those typically observed in the clinic. Also, the recently developed inner ear model was combined with the classical middle ear model to mimic tympanograms of the ear with a flaccid eardrum. Applying the circuit model to different middle ear diseases can provide a better understanding of the mechanism of tympanometry and promote its clinical utility.
Convenient design and implementation of ground calibration experiments of the Omnidirectional Ion Analyzer based on LabVIEW
Qiu Zihao, Sun Zhenyu, Li Yiren, Hao Xinjun, Miao Bin, Shen Chenglong
2020, 50(11): 1440-1446. doi: 10.3969/j.issn.0253-2778.2020.11.008
The Omnidirectional Ion Analyzer is mounted on a Chinese navigation satellite to detect low-energy (5eV~25 keV) ions in the space near geosynchronous orbit. Before the detector in-flight, the ground calibration experiment is the key step to understand the ion detection results in space. According to the calibration experiment requirements of the Omnidirectional Ion Analyzer, a specific calibration experiment process is designed to manipulate the automation of complex experiments, so as to avoid the error caused by manually operating experiment and improve experimental efficiency. Aiming at the calibration experiment of the Omnidirectional Ion Analyzer, the method and program template of using LabVIEW to quickly design the calibration software system were presented, which provides a reference for the complex experimental design similar to the calibration of an ion analyzer and increases program reusability. The experiment results show that the test software runs stably and reliably, reduces the software development cycle, improves test efficiency, and can accurately control the multi-axis turntable and carry out real-time and accurate information processing.