过刊目录

2016, Vol. 25, No. 4　Online: 2016-07-15


上一期    下一期

Power-to-gas processes are considered as a promising solution to integrate renewable resources, such as wind and solar energy, into the current energy mix. This updated review comprehensively describes recent publications on the catalytic CO₂ methanation processes, with various aspects of consideration in this reaction system, such as thermodynamics, catalyst innovations, influence of the reaction conditions, and the reaction mechanism. As a promising CO₂ methanation process requires a limited energy input and targeting at an economically affordable market, the exploration of efficient catalysts is the main challenge. Yet, it may play a pivotal role for the future renewable energy storage systems.

全全选选:

导出引用 EndNote Ris BibTeX

隐藏/显示图片

REVIEW

Select

Catalytic carbon dioxide hydrogenation to methane: A review of recent studies Xiong Su, Jinghua Xu, Binglian Liang, Hongmin Duan, Baolin Hou, Yanqiang Huang 2016, 25(4): 553-565.  DOI: 10.1016/j.jechem.2016.03.009 摘要 ( 5202 )   Recently, various efforts have been put forward on the development of technologies for the synthesis of methane from CO2 and H2, since it can offer a solution for renewable H2 storage and transportation. In parallel, this reaction is considered to be a critical step in reclaiming oxygen within a closed cycle. Over the years, extensive fundamental research works on CO2 methanation have been investigated and reported in the literatures. In this updated review, we present a comprehensive overview of recent publications during the last 3 years. Various aspects on this reaction system are described in detail, such as thermodynamic considerations, catalyst innovations, the influence of reaction conditions, overall catalytic performance, and reaction mechanism. Finally, the future development of CO2 methanation is discussed.

ARTICLES

Select

Sulphur-doped ordered mesoporous carbon with enhanced electrocatalytic activity for the oxygen reduction reaction Liping Wang, Weishang Jia, Xiaofeng Liu, Jingze Li, Maria Magdalena Titirici 2016, 25(4): 566-570.  DOI: 10.1016/j.jechem.2016.02.012 摘要 ( 4086 )   Metal-free, heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation. In this study, high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template SiO2. 2- thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%. Comparing with pristine carbon, the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution.

Select

Optimization of MgO/Al2O3 ratio for the maximization of active site densities in the Ni2P/MgAlO catalysts for the hydrotreating reactions Junen Wang, Xiaogan Wang, Yamei Yuan, Abdalla Shuaib, Jianyi Shen 2016, 25(4): 571-576.  DOI: 10.1016/j.jechem.2016.03.005 摘要 ( 3733 )   The Ni2P/MgAlO catalysts with different MgO/Al2O3 ratios were prepared by the phosphidation of corresponding Ni/MgAlO catalysts with triphenylphosphine in liquid phase. It was found that the MgO/Al2O3 ratio affected the Ni2P/MgAlO catalysts significantly. The Ni2P/MgAlO catalyst with the MgO/Al2O3 ratio of 3 (w/w) exhibited the highly dispersed Ni2P particles (～9 nm) with the highest CO uptake (344μmol/g) and thus the highest activities for the hydrotreating reactions. However, based on the CO uptakes on the used catalysts, the TOF values for the hydrodesulphurization of dibenzothiophene as well as those for the hydrogenation of tetralin on all the Ni2P/MgAlO catalysts were respectively similar, indicating that the MgO/Al2O3 ratio did not affect the intrinsic activities of Ni2P supported on the MgAlO support for the hydrotreating reactions.

Select

Promoted catalytic performances of highly dispersed V-doped SBA-16 catalysts for oxidative dehydrogenation of ethane to ethylene Lian Kong, Jianmei Li, Qinglong Liu, Zhen Zhao, Qianyao Sun, Jian Liu, Yuechang Wei 2016, 25(4): 577-586.  DOI: 10.1016/j.jechem.2016.04.004 摘要 ( 4057 )   V-doped SBA-16 catalysts (V-SBA-16) with 3D nanocage mesopores have been successfully synthesized by a modified one-pot method under weak acid condition. The obtained materials were characterized by means of small angle XRD, N2 adsorption-desorption, TEM, UV-Vis and UV-Raman spectroscopy. These characterization results indicated that well-order mesoporous structures were maintained even at higher vanadium loadings and high concentration of VOx species were incorporated into the framework of SBA- 16 support. The catalytic performances of V-SBA-16, V/SBA-16 and V/SiO2 catalysts were comparatively investigated for the oxidative dehydrogenation of ethane to ethylene. The highest selectivity to ethylene of 63.3% and ethylene yield of 25.6% were obtained over 1.0V-SBA-16 catalyst. The superior catalytic performance of V-SBA-16 catalysts could be attributed to the presence of isolated framework VOx species, the unique structure of SBA-16 support and weak acidity. Moreover, V/SiO2 catalyst exhibited relatively poor catalytic activity duo to the formation of V2O5 nanoparticles on the surface of SiO2 support and the low dispersion of VOx species. These results indicated that the catalytic performances of the studied catalysts were strongly dependent on the vanadium loading, the nature and neighboring environment of VOx species and the structure of support.

Select

Microporous carbon nanofibers prepared by combining electrospinning and phase separation methods for supercapacitor Chang Liu, Yongtao Tan, Ying Liu, Kuiwen Shen, Bowu Peng, Xiaoqin Niu, Fen Ran 2016, 25(4): 587-593.  DOI: 10.1016/j.jechem.2016.03.017 摘要 ( 3828 )   Microporous carbon nanofibers (MCNFs) derived from polyacrylonitrile nanofibers were fabricated via electrospinning technology and phase separation in the presence of polyvinylpyrrolidone (PVP). PVP together with a mixed solvent of N, N-Dimethylformamide and dimethyl sulfoxide was used as poreforming agent. The influences of PVP content in casting solution on the structure and electrochemical performance of the MCNFs were also investigated. The highest capacitance of 200 F/g was obtained on a three-electrode system at a scan rate of 0.5 A/g. The good performance was owing to the high specific surface area and the large amount of micro-pores, which enhanced the absorption and the transportation efficiency of electrolyte ion during charge/discharge process. This research indicated that the combination of electrospinning and phase separation technology could be used to fabricate microporous carbon nanofibers as electrode materials for supercapacitors with high specific surface area and outstanding electrochemical performance.

Select

In-situ hydrothermal synthesized γ-Al2O3/O-g-C3N4 heterojunctions with enhanced visible-light photocatalytic activity in water splitting for hydrogen Yu Wang, Yaping Zeng, Boqiao Li, Anqi Li, Ping Yang, Liu Yang, Gang Wang, Jinwei Chen, Ruilin Wang 2016, 25(4): 594-600.  DOI: 10.1016/j.jechem.2016.03.018 摘要 ( 4100 )   In this work, γ-Al2O3 and hydrogen peroxide treated g-C3N4 (O-g-C3N4) were combined through a novel in-situ hydrothermal method to form heterojunction structured photocatalysts. These photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy (PL). FT-IR results indicate that oxygen functional groups can be grafted on the surface of O-g-C3N4 by hydrogen peroxide treatment. The visible light photocatalytic hydrogen evolution rate was investigated in 10 vol% TEOA aqueous solution. The optimal Al2O3 mass content is set to be 20 wt% and the corresponding hydrogen evolution rate is 1288 μmol/h/g which is approximately 6, 3 folds that of pristine g-C3N4 and O-g-C3N4 respectively and 1.6 folds that of mechanical mixed composite with the same Al2O3 mass content. The photocurrent density-time curves were carried out under visible light illumination for four on-off cycles. The electrochemical impedance spectroscopy (EIS) measurements verified the enhanced separation efficiency of electron-hole pairs. This work raised a new method to form the heterojunction structured photocatalysts and achieved a remarkable improvement of the photocatalytic activity in water splitting for hydrogen under visible light irradiation.

Select

Simple synthesis of novel phosphate electrode materials with unique microstructure and enhanced supercapacitive properties Maocheng Liu, Jiajia Li, Wei Han, Long Kang 2016, 25(4): 601-608.  DOI: 10.1016/j.jechem.2016.03.002 摘要 ( 4199 )   Flower-like Ni3P2O8 and flower-like Fe3P2O8·8H2O have been successfully synthesized by a simple chemical precipitation method. X-ray diffraction (XRD) patterns reveal an amorphous phase formation of nickel phosphate (Ni3P2O8) and pure monoclinic phase of Fe3P2O8·8H2O. The novel flower-like Ni3P2O8 and flower-like Fe3P2O8·8H2O when used for supercapacitor electrode materials exhibit a high specific capacitance (Cm) of 1464 F/g and 200 F/g at a current density of 0.5 A/g, respectively. Eventually, an asymmetric supercapacitor is fabricated using Ni3P2O8 as positive electrode and Fe3P2O8·8H2O as negative electrode. A high specific capacitance of 94 F/g is achieved in the high-voltage region of 0~1.6 V, and a large energy density of 32.6Wh/kg is delivered at power density of 420 W/kg. The findings demonstrate the important and great potential of developing metal phosphate based materials for supercapacitors.

Select

Ionic liquid-1,2-dimethoxyethane mixture as electrolyte for high power density supercapacitors A. Jänes, J. Eskusson, T. Thomberg, T. Romann, E. Lust 2016, 25(4): 609-614.  DOI: 10.1016/j.jechem.2016.02.011 摘要 ( 4254 )   In this work we have studied the effect of 1,2-dimethoxyethane (1,2-DME) addition (from 0 to 90 vol%) on the electrochemical behaviour of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide (EMImTFSI) as an electrolyte for supercapacitors, using cyclic voltammetry, electrochemical impedance spectroscopy and constant power methods. Also, the ionic conductivity and viscosity of EMImTFSI and 1,2-DME have been measured and discussed. The conductivity of the EMImTFSI could be increased from 5.67 mS/cm up to 24.21 mS/cm by mixing EMImTFSI with 1,2-DME. The stored power values for supercapacitors increased from 13 kW/kg to 20.5 kW/kg (correspond to 2 s application line), when the concentration of 1,2-DME increased up to 40 vol%. The supercapacitors based on the 40 vol% of 1,2-DME deliver the higher power density at the constant energy density, showing an excellent characteristics applicable in high rate supercapacitor devices. Nearly ideal capacitive behaviour has been established at potential scan rates v ≤ 10 mV/s and cell potential ΔE ≤ 2.7 V.

Select

Organic dyes based on triphenylamine for dye-sensitized solar cells: Structure-property relationships Huixia Shang, Qikai Li, Kejian Jiang, Xiaowei Zhan 2016, 25(4): 615-620.  DOI: 10.1016/j.jechem.2016.03.007 摘要 ( 4084 )   Three new organic dyes based on triphenylamine with a structure of A-D-A-D-A (D1), A-D-A (D2) and D-A (D3) were designed, theoretically calculated and synthesized for dye-sensitized solar cells. Dye D1 exhibits a broader absorption than D2 and D3, due to the intramolecular charge transfer between the donor triphenylamine and the acceptor benzothiadiazole. Dye D1 exhibits a lower HOMO and a lower LUMO than D2 and D3 due to the electron-withdrawing benzothiadiazole. The number of anchoring group cyanoacrylic acid has no obvious influence on absorption and energy levels of D2 and D3. The LUMO of D1 locates on benzothiadiazole rather than cyanoacrylic acid anchoring groups, while the LUMOs of D2 and D3 are localized on cyanoacrylic acid. D2 and D3 give higher short-circuit current density than D1. D3 with one anchoring group gives the highest open-circuit voltage. Consequently, the D3-based device gives the highest efficiency.

Select

Photocatalytic activity of different morphology BiPO4 supported on zeolite Haiyan Yu, Ting Cui, Zhifeng Liu 2016, 25(4): 621-626.  DOI: 10.1016/j.jechem.2016.03.016 摘要 ( 3784 )   Highly efficient sheet-like BiPO4/zeolite and ball-flower-like BiPO4/zeolite had been successfully synthesized by a standard hydrothermal method. The addition of assistant reagent in the hydrothermal system is promising to obtain special morphology. The assistant reagent (EDTA) acts as a growth modifier of crystal. The possible formation mechanisms of sheet-like BiPO4/zeolite and ball-flower-like BiPO4/zeolite were schematically discussed. A detailed study of sheet-like BiPO4/zeolite and ball-flower-like BiPO4/zeolite impacted on the photodecoloration methylene blue (MB) solution showed that the composite had a highly reusable and stable property for long-run photocatalytic application.

Select

High energy density performance of hydrothermally produced hydrous ruthenium oxide/multiwalled carbon nanotubes composite: Design of an asymmetric supercapacitor with excellent cycle life K. Chaitra, P. Sivaraman, R. T. Vinny, Umananda M. Bhatta, N. Nagaraju, N. Kathyayini 2016, 25(4): 627-635.  DOI: 10.1016/j.jechem.2016.04.012 摘要 ( 4121 )   Hydrous ruthenium oxide (h-RuO2) nanoparticles and its composite with multiwalled carbon nanotubes (h-RuO2/MWCNT) were synthesized by a simple hydrothermal method and proved to have potential application as hybrid supercapacitor material. The h-RuO2 and h-RuO2/MWCNT were characterized for their physico-chemical properties by PXRD, BET surface area, Raman, SEM-EDS and TEM techniques. The electrochemical performance of the materials were investigated, specific capacitance (Cs) of h-RuO2 and h- RuO2/MWCNT estimated by their cyclic voltammetric studies were found to be 604 and 1585 F/g respectively at a scan rate of 2 mV/s in the potential range 0-1.2 V. Further, this value was found to be nearly three times higher than that of pure h-RuO2. An asymmetric supercapacitor (AS) device was fabricated by employing h-RuO2/MWCNT as the positive electrode and activated carbon as the negative electrode. The device exhibited Cs of 61.8 F/g at a scan rate of 2 mV/s. Further, the device showed excellent long term stability for 20,000 cycles with 88% capacitance retention at a high current density of 25 A/g.

Select

ZnO sheets prepared with a light-assisted growth method for improved photodegradation performance Xuewen Wang, Yuanquan Miao, Wuyou Wang, Gang Feng, Rongbin Zhang 2016, 25(4): 636-640.  DOI: 10.1016/j.jechem.2016.03.006 摘要 ( 3555 )   ZnO as a semiconductor photocatalyst is widely applied in the photodegradation of organic pollutants. Its photocatalytic activity is greatly decreased because of the recombination of photoexcited electrons and holes in the bulk. In this work, ZnO sheets are synthesized by adjusting the NaOH concentration under light irradiation at room temperature. Compared with ZnO particles, the ZnO sheets prepared with a light-assisted growth method exhibit a higher rate of photodegradation of methylene blue under UV- visible light irradiation. The improved photodegradation rate is mainly attributed to the shortened transport distance of photoexcited electrons, the high surface area, and the surface atom structure modified by the light-assisted growth process.

Select

Studies on the preliminary cracking: The reasons why matrix catalytic function is indispensable for the catalytic cracking of feed with large molecular size Bin Wang, Nan Li, Qiang Zhang, Chunyi Li, Chaohe Yang, Honghong Shan 2016, 25(4): 641-653.  DOI: 10.1016/j.jechem.2016.02.014 摘要 ( 3735 )   The matrix catalytic function when cracking the feed oil with large molecular size was systematically studied using three different catalyst configurations, including staged bed, partly mixed bed and completely mixed bed. Results showed that molecules in the feed oil with large molecular size indeed preferred to be first precracked on the matrix surface and then entered into the zeolite pores during the practical reaction process. Furthermore, the matrix catalytic function exhibited a great matrix-precracking ability to large feed molecules, which considerably increased the catalyst activity and the light oil selectivity. Besides the much better accessibility, the matrix-precracking ability was also from the similar capability to crack large feed hydrocarbons into the moderate fragments with that of the zeolite component. More interestingly, the interactions between the matrix catalytic function and the zeolite catalytic function made the catalyst not only exhibit much more catalytic advantages of the zeolite component, but also retain the matrix-precracking ability. As a result, the interactions enhanced the catalyst activity and improved the product distribution at the same time. The matrix catalytic function is indispensable for the catalytic cracking of feed with large molecular size, although the matrix component itself presented an inferior catalytic performance than the zeolite component did.

Select

Double laminated reduced graphene/Cu2S/reduced graphene/graphene oxide nanofilms and their photoelectrochemical properties Junwei Li, Xueqi Zhang, Li Song, Min Zhang, Baohang Zhang 2016, 25(4): 654-658.  DOI: 10.1016/j.jechem.2016.04.003 摘要 ( 3270 )   In this work, an efficient photocatalytic material was prepared directly on Indium tin oxide (ITO) glass substrates by fabricating Cu2S and graphene oxide onto graphene for photoelectrochemical (PEC) water splitting. The double laminated reduced graphene/Cu2S/reduced graphene/graphene oxide (RG/Cu2S/RG/GO) nanofilms were characterized, and an enhanced photoelectrochemical response in the visible region was discovered. The photocurrent density of the nanofilms for PEC water splitting was measured to be up to 1.98 mA/cm2, which could be ascribed to the followings: (i) a higher efficiency of light-harvesting because of GO coupling with Cu2S that could broaden the absorbing solar spectrum and enhance the light utilization efficiency; (ii) a stepwise structure of band-edge levels in the Cu2S/GO electrode was constructed; (iii) double laminated electron accelerator (RG) was used in the Cu2S/GO materials to get better electron-injecting efficiency.

Select

Tris(trimethylsilyl) borate as an electrolyte additive for high-voltage lithium-ion batteries using LiNi1/3Mn1/3Co1/3O2 cathode Chunfeng Yan, Ying Xu, Jianrong Xia, Cuiran Gong, Kerong Chen 2016, 25(4): 659-666.  DOI: 10.1016/j.jechem.2016.04.010 摘要 ( 4669 )   The influence of tris(trimethylsilyl) borate (TMSB) as an electrolyte additive on lithium ion cells have been studied using Li/LiCo1/3Ni1/3Mn1/3O2 cells at a higher voltage, 4.7 V versus Li/Li+. 1wt% TMSB can dramatically reduce the capacity fading that occurs during cycling at room temperature (RT) and elevated temperature (60 ℃). After 150 cycles at 1C rate (1C= 278mAh/g), the capacity retention of Li/LiCo1/3Ni1/3Mn1/3O2 is up to near 72% in the electrolyte with TMSB added, while it is only about 35% in the baseline electrolyte. The electrochemical behaviors, the surface chemistry and structure of Li/LiCo1/3Ni1/3Mn1/3O2 cathode are characterized with charge/discharge test, linear sweep voltammetry (LSV), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), thermal gravimetric analyses (TGA), scanning electron microscope (SEM) and transmission electron microscopy (TEM). These analysis results reveal that the addition of TMSB is able to protectively modify the electrode CEI film in a manner that suppresses electrolyte decomposition and degradation of electrode surface structure, even though at both a higher voltage of 4.7 V and an elevated temperature of 60 ℃.

Select

Role of nickel on vanadium poisoned FCC catalyst: A study of physiochemical properties U. J. Etim, B. Xu, P. Bai, Rooh Ullah, F. Subhan, Z. Yan 2016, 25(4): 667-676.  DOI: 10.1016/j.jechem.2016.04.001 摘要 ( 3368 )   Active sites of Fluid catalytic cracking (FCC) catalyst are poisoned during operation in the FCC reactor due to causes including feedstock contaminant metals deposition. This leads to activity, selectivity and increasing coking problems, thereby raising concern to the refiner. This work investigated effect of nickel coexisting with vanadium in the FCC feedstock on the standard FCC catalyst during cracking process, in which destruction of active sites occurs as a result of the metals deposition. Laboratory simulated equilibrium catalysts (E-cats) were studied by XRD, FTIR spectroscopy, N2 adsorption, solid state MAS-NMR, SEM and H2-TPR. Results revealed that vanadium, above a certain concentration in the catalyst, under hydrothermal conditions, is highly detrimental to the catalyst's structure and activity. Conversely, nickel hardly affects the catalyst structure, but its co-presence in the catalyst reduces destructive effects of vanadium. The mechanism of nickel inhibition of vanadium poisoning of the catalyst is discussed.

Select

Theoretical insight into the enhanced CH4 desorption via H2O adsorption on different rank coal surfaces Yanan Zhou, Wenjing Sun, Wei Chu, Xiaoqiang Liu, Fangli Jing, Ying Xue 2016, 25(4): 677-682.  DOI: 10.1016/j.jechem.2016.04.011 摘要 ( 2898 )   The density functional theory was used to investigate the adsorption of CH4 and H2O on different rank coal surfaces. The coal rank is the dominant factor in affecting the adsorption capacity of coal. In order to better understand gas and water interaction with coal of different maturity, we developed fourteen coal models to represent the different rank coal. The interactions of CH4 and H2O with coal surfaces were studied and characterized by their adsorption energies, Mulliken charges and electrostatic potential surfaces. The results revealed that the interaction between coal and CH4 was weak physical adsorption, and that the interaction between coal and H2O consisted of physical and chemical adsorption. Adsorption energy of coal-H2O system was larger than that of coal-CH4 on all rank coals, suggesting that the adsorption priority in the coal models is H2O > CH4. Consequently, the injection of H2O into the different rank coal could effectively enhance the coal bed methane (CBM) recovery.

Select

Electro-oxidation of mixed reactants of ethanol and formate on Pd/C in alkaline fuel cells Myounghoon Choun, Jaeyoung Lee 2016, 25(4): 683-690.  DOI: 10.1016/j.jechem.2016.04.008 摘要 ( 3202 )   Direct ethanol fuel cells have attracted attention as an alternative energy technology due to several advantages such as high theoretical energy density and abundant supply of ethanol. In spite of the advantages, commercialization of direct ethanol fuel cells is hampered by the relatively low performance caused by its slow oxidation kinetics and difficulty of complete oxidation. In this study, formate, which has relatively faster oxidation kinetics, was mixed with ethanol to compensate the latter's sluggish kinetics. Effects of pH, concentration, scan rate, and temperature on the mixed reactants oxidation on Pd were investigated by electrochemical experiments such as potential sweep and potentiostatic methods. Furthermore, the potential of the mixed reactants as fuel was evaluated by single cell experiments. As a result, we demonstrate that mixing formate with ethanol results in enhanced power performance in a single cell system.

Select

Tin stearate organometallic precursor prepared SnO2 quantum dots nanopowder for aqueous- and non-aqueous medium photocatalytic hydrogen gas evolution Choonyian Haw, Weesiong Chiu, Noor Hamizah Khanis, Saadah Abdul Rahman, Poisim Khiew, Shahidan Radiman, Roslan Abd-Shukor, Muhammad Azmi Abdul Hamid 2016, 25(4): 691-701.  DOI: 10.1016/j.jechem.2016.04.006 摘要 ( 4240 )   Current study reports a rapid one-pot non-hydrolytic condition in the synthesis of SnO2 QDs nanopowder using tin (II) stearate (Sn(St)2) as environmentally-benign organometallic precursor, which is an unprecedentedly employed-compound in preceding SnO2 nanopowder productions. The as-synthesized SnO2 QDs that are hydrophobic can be easily transferred from organic solvent to aqueous solution through a robust ligand exchange method. The stearate-capping ligands on the surface of QDs can be replaced by beta-cyclodextrin (β-CD) and eventually render the QDs highly water soluble, which ultimately make it exhibit bi-functionality for different liquid medium applications. Structural characterizations reveal that the bi-functional QDs are indeed well-matched with the standard rutile SnO2 cassiterite phase without the presence of any impurities. The QDs can be interchangeably used as photocatalyst for both aqueous and non-aqueous phase, where it shows significant enhancement of hydrogen gas production as compared to that of commercial SnO2 nanopowder.

Select

Application of phenonaphthazine derivatives as hole-transporting materials for perovskite solar cells Xueyuan Liu, Fei Zhang, Xicheng Liu, Mengna Sun, Shirong Wang, Dongmei Li, Qingbo Meng, Xianggao Li 2016, 25(4): 702-708.  DOI: 10.1016/j.jechem.2016.03.021 摘要 ( 3725 )   Two electron-rich, solution-processable phenonaphthazine derivatives, 5,12-bis{N-[4,4'-bis-(phenyl)-aminophen-4"-yl]}-phenonaphthazine (BPZTPA) and 5,12-bis{N-[4,4'-bis(methoxy-phenyl)aminophen-4"-yl]} -phenonaphthazine (MeO-BPZTPA) have been designed and employed in the fabrication of perovskite solar cells. BPZTPA and MeO-BPZTPA exhibit excellent thermal stabilities, hole mobilities (～10-4 cm2/(V·s)) and suitable HOMO levels (-5.34 and -5.29 eV, respectively) relative to the valence band of the CH3NH3PbI3 and Au work function, showing their potential as alternative hole-transporting materials (HTMs). Meanwhile, the corresponding mesoporous TiO2/CH3NH3PbI3/HTM/Au devices are investigated, and the best power conversion efficiency of 10.36% has been achieved for MeO-BPZTPA without using p-type dopant.

Select

Catalytic performances of Ni/mesoporous SiO2 catalysts for dry reforming of methane to hydrogen Fei Huang, Rui Wang, Chao Yang, Hafedh Driss, Wei Chu, Hui Zhang 2016, 25(4): 709-719.  DOI: 10.1016/j.jechem.2016.03.004 摘要 ( 4340 )   Several mesoporous silicas with different morphologies were controllably prepared by sol-gel method with adjustable ratio of dual template, and they were further impregnated with aqueous solution of nickel nitrate, followed by calcination in air. The synthesized silica supports and supported nickel samples were characterized using N2-adsorption/desorption, X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), Scanning electron microscope (SEM), Transmission electron microscope (TEM) and thermo-gravimetric analysis (TGA-DTG) techniques. The Ni nanoparticles supported on shell-like silica are highly dispersed and yielded much narrower nickel particle-size than those on other mesoporous silica. The methane reforming with dioxide carbon reaction results showed that Ni nanoparticles supported on shell-like silica carrier exhibited the better catalytic performance and catalytic stability than those of nickel catalyst supported on other silica carrier. The thermo-gravimetric analysis on used nickel catalysts uncovered that catalyst deactivation depends on the type and nature of the coke deposited. The heterogeneous nature of the deposited coke was observed on nickel nanoparticles supported on spherical and peanut-like silica. Much narrower and lower TGA derivative peak was founded on Ni catalyst supported on the shell-like silica.

Select

Modified carbon cloth as positive electrode with high electrochemical performance for vanadium redox flow batteries Zhangxing He, Zhongsheng Chen, Wei Meng, Yingqiao Jiang, Gang Cheng, Lei Dai, Ling Wang 2016, 25(4): 720-725.  DOI: 10.1016/j.jechem.2016.04.002 摘要 ( 3870 )   Carbon cloth modified by hydrothermal treatment in ammonia water is developed as the positive electrode with high electrochemical performance for vanadium redox flow batteries. The SEM shows that the treatment has no obvious influence on the morphology of carbon cloth. XPS measurements indicate that the nitrogenous functional groups can be introduced on the surface of carbon cloth successfully. The electrochemical performance of V(IV)/V(V) redox couple on the prepared electrode is evaluated with cyclic voltammetry and linear sweep voltammetry measurements. The N-doped carbon cloth exhibits outstanding electrochemical activity and reversibility toward V(IV)/V(V) redox couple. The rate constant of V(IV)/V(V) redox reaction on carbon cloth can increase to 2.27 × 10-4 cm/s from 1.47 × 10-4 cm/s after nitrogen doping. The cell using N-doped carbon cloth as positive electrode has larger discharge capacity and higher energy efficiency compared with the cell using pristine carbon cloth. The average energy efficiency of the cell using N-doped carbon cloth for 50 cycles at 30mA/cm2 is 87.8%, 4.3% larger than that of the cell using pristine carbon cloth. It indicates that the N-doped carbon cloth has a promise application prospect in vanadium redox flow batteries.

Select

Ti3+ self-doped TiO2 photoelectrodes for photoelectrochemical water splitting and photoelectrocatalytic pollutant degradation Chaoyi Wu, Zhenggang Gao, Shanmin Gao, Qingyao Wang, Hui Xu, Zeyan Wang, Baibiao Huang, Ying Dai 2016, 25(4): 726-733.  DOI: 10.1016/j.jechem.2016.04.009 摘要 ( 3915 )   To improve the harvesting of visible light and reduce the recombination of photogenerated electrons and holes, Ti3+ self-doped TiO2 nanoparticles were synthesized and assembled into photoanodes with high visible light photoelectrochemical properties. X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectra, electron resonance spectroscopy and energy dispersive X-ray spectra were used to characterize the structure, crystallinity, morphology and other properties of the obtained nanoparticles. UV-visible diffuse reflectance spectra showed that the Ti3+ self-doped TiO2 nanoparticles had a strong absorption between 400 and 800 nm. Moreover, when hydrothermal treatment time was prolonged to 22 h, the heterogeneous junction was formed between the anatase and rutile TiO2, where the anatase particles exposed highly active {001} facets. Under visible light irradiation, the Ti3+ self-doped TiO2 electrode exhibited an excellent photoelectrocatalytic degradation of rhodamine B (RhB) and water splitting performance. Intriguingly, by selecting an appropriate hydrothermal time, the high photoconversion efficiency of 1.16% was achieved.

Select

Superior supercapacitive performance in porous nanocarbons Gomaa A. M. Ali, Shoriya Aruni Abdul Manaf, Divyashree A, Kwok Feng Chong, Gurumurthy Hegde 2016, 25(4): 734-739.  DOI: 10.1016/j.jechem.2016.04.007 摘要 ( 3408 )   Porous nanocarbons with average particle size 20-40 nm were developed using biowaste oil palm leaves as a precursor. Simple pyrolysis was carried out at 700 ℃ under nitrogen atmosphere. Obtained porous nanocarbons showed excellent porous nature along with spherical shape. Symmetric supercapacitor fabricated from porous nanocarbons showed superior supercapacitance performance where high specific capacitance of 368 F/g at 0.06 A/g in 5M KOH were reported. It also exhibited high stability (96% over 1700 cycles) and energy density of 13 Wh/kg. Low resistance values were obtained by fitting the impedance spectra, thus indicating the availability of these materials as supercapacitors electrode. The presented method is cost effective and also in line with waste to wealth approach.

Select

Photocatalytic decompositions of gaseous HCHO and methylene blue with highly ordered TiO2 nanotube arrays Lixia Li, Jing Ya, Fengjiao Hu, Zhifeng Liu, Lei E 2016, 25(4): 740-746.  DOI: 10.1016/j.jechem.2016.03.003 摘要 ( 3401 )   The highly ordered TiO2 nanotubes (NTs) were fabricated by the anodic oxidation method. Their morphology, structure and crystalline phase were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). The effects of morphology, specific surface area, pore structures and photocatalytic activity of the TiO2 NTs were investigated. UV-vis spectra analysis showed that its light absorption had been extended to the visible light range. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic oxidation of gaseous HCHO and MB aqueous solution. The samples had better adhesion strength in the dark and showed a higher photocatalytic activity than nanoparticles. Especially, with ultraviolet light pretreatment, the nanotubes exhibited more stable active for photocatalytic decomposition and the photodecomposition rate remained at high level after 3 cycles of the photocatalysis experiment. Thus, how the number of surface active group ·OH increased and the mechanism for the great improvement for the photocatalytic activity are discussed.