Institutional Repository of Dalian Institute of Chemical Physics, CAS
Not a member yet
45557 research outputs found
Sort by
Goldschmidt-rule-deviated perovskite CsPbIBr(2)by barium substitution for efficient solar cells
No full textAll-inorganic Br-rich perovskite photovoltaics with excellent stability have gained ever-increasing attention despite their slightly lower efficiency. Nowadays, trace heteroatom substitution has become a plausible approach to optimize perovskite properties as well as device performance. However, the substitution is limited by the Goldschmidt tolerance factor (t, 0.8 < t < 1.0), leading to the situation that the alternative deviating from the Goldschmidt rule is always overlooked, let alone utilized to enhance performance. Given this, Ba(II) is partially substituted for Pb(II) in CsPbIBr2 to investigate how the dopants-induced deviation from the Goldschmidt rule would affect perovskite property. Intriguingly, the result verifies that Ba(II) enables increased the grain size and enhances the crystallinity of CsPbIBr2. As such, the trap state density is reduced and the non-radiative recombination in the perovskite is suppressed. These advantages bring about an increase of the power conversion efficiency (PCE) of Ba(II)-doped devices to 10.51%, outperforming that (8.4%) of the pristine counterpart. In addition, the perovskite stability is immune to Ba(II) substitution, even though it inflates the perovskite crystal lattice. These findings indicate that the perovskite films are tolerant to homovalent heteroatoms with a larger radius, stimulating further development of perovskite substitution engineering
From reverse osmosis to nanofiltration: Precise control of the pore size and charge of polyamide membranes via interfacial polymerization
No full textMembranes with suitable nanopores and tunable charge characteristics are highly desired for their good application prospects in specific membrane-based separations. This study focused on the synthesis of polyamide (PA) composite membranes with tunable pore size and perm-selectivity. Trimellitic anhydride chloride (TAC) with an anhydride group, was introduced as the co-reactant of trimesoyl chloride (TMC) to form PA film via interfacial polymerization with m-phenylenediamine on the surface of the polysulfone substrate membrane. Due to the chemistry character difference (the number of functional group and acylation activity) between TMC and TAC, the structure and physico-chemistry properties of the PA film could be tailored through the control of TAC concentration. As a result, the nanopore radius of the membrane varied from < 0.32 to 1.14 nm, along with the improved water permeability from 2.3 to 9.8 L m(-2) h(-1) bar(-1) and selectivity of Na2SO4/NaCl from 2.2 to 4.9. This study provided a facile and effective approach for the fabrication of tailor-made membrane with tunable nanopore and ion selectivity designed at a molecular level
Toluene Enhanced-High Pressure Photoionization-Time-of-Flight Mass Spectrometry for Highly Sensitive and Rapid Detection of Phenolic Compounds
No full textPhenolic compounds are toxic and difficult to be degraded, and can cause serious pollution to the environment. Conventional off-line detection methods for phenolic compounds mostly require complicated and time-consuming pretreatment process. Therefore, it is an urgent need to develop a method for highly sensitive and rapid measurement of phenolic compounds. In this work, a novel toluene enhanced-high pressure photoionization (TE-HPPI) source, based on a vacuum ultraviolet (VUV) lamp filling with krypton (Kr) gas, was developed for rapid detection of phenolic compounds by time-of-flight mass spectrometry (TOFMS). By introducing toluene as the reagent molecule and elevating the ion source pressure, the detection sensitivities for 0. 5 mu g/L phenol, 3 -methylphenol, 2-chlorophenol, 2, 4-dichlorophenol and 2, 4, 6-trichloropenol were improved by 14.8, 2.68, 2.47, 2.33 and 2.30 times, respectively. The ionization process of phenolic compounds was not affected by sample humidity. A dynamic bubbling and purging inlet method was employed to measure phenolic compounds in liquid samples without any pretreatment process. The limits of detection ( LODs ) of phenol, 3-methylphenol, 2-chlorophenol, 2, 4-dichlorophenol and 2, 4, 6-trichloropenol in gas phase within 1 min were down to 0.24, 1.43, 0.42, 19.8 and 29.1 ng/L, respectively, while the LODs were 4.87, 3.60, 0.21, 1.50 and 4.32 mu g/L in solution, respectively. The method was successfully applied 14 analyzing phenolic compounds in sludge suspension from sewage treatment plants. The capability of high sensitivity, fast analysis, few fragmentation and simple spectrum interpretation have made the TE-HPPI-TOFMS as a promising tool in rapid detection and online monitoring of phenolic pollutants
Efficient Design for a High-Energy and High-Power Capability Hybrid Electric Power Device with Enhanced Electrochemical Interfaces
No full textFabrication of novel electrode architectures with tailored electrochemical interfaces (EI) is an effective strategy for enhancing charge and mass transport processes within electrochemical devices. Here, we design and fabricate a well-hybrid electrode based on the coupling of polyaniline (PANI) nanowires and Pt-based electrocatalysts to manufacture a hybrid electric power device (HEPD) combining the advantages of supercapacitors and fuel cells. Because of the boosted charge transfer between PANI nanowires and Pt-based materials via enhanced EIs, the HEPD assembled with hybrid electrodes shows remarkable performance with a peak power density of 222 mW cm(-2), a specific power of 3810 W kg(-1), and a specific energy of 2100 Wh kg(-1), normalized to the mass of membrane electrode assemblies. The in situ Raman spectra and extended electrochemical studies demonstrate the intrinsic mechanism of charge transfer processes within hybrid electrodes, shedding light on the alternative progress of electrochemical energy conversion systems and storage devices
preparationofzro2modifiedal2o3nanosheetssupportedcobaltcatalystanditsperformanceinfischertropschsynthesis
No full textAl 2 O 3 nano-sheet (Al 2 O 3 -CN) was synthesized under hydrothermal condition. The cobalt-based catalyst of 20% (mass fraction) was prepared by impregnation method and applied to Fischer-Tropsch synthesis. The Al 2 O 3 -CN (226 m 2 2 O 3 -C, 249 m 2 2 O 3 -CN has more narrow pore size distribution. Compared with Co 2 O 3 -C catalyst, Co 2 O 3 -CN catalyst showed higher reduction degree and more uniform cobalt particle size distribution after impregnation. Thus, Co 2 O 3 -CN catalyst exhibited higher CO conversion and lower methane selectivity. In order to further improve the catalytic performance of Co 2 O 3 -CN, Al 2 O 3 -CN was modified with ZrO 2 . The characterization results showed that with the increase of ZrO 2 , the specific surface of Al 2 O 3 -CN did not change significantly, and the pore volume and pore diameter increased. The cobalt particle size decreased and the number of active sites increased. Under the same reaction conditions, the CO conversion rate of catalysts modifield by ZrO 2 was further improved and selectivity of methane was decreased
水分子f态超快动力学时间分辨光电子能谱研究
No full text本文利用双光子激发和时间分辨的光电子成像技术研究了水分子F态的超快动力学.这是首次对水分子F态进行时间分辨的实验研究.水(重水)分子F1A1和F1B1态的寿命分别为1.0±0.3(1.9±0.4)和10±3(30±10)皮秒.我们提出F1A1态主要通过非绝热耦合内转换到D态,而F1B1态通过科里奥利相互作用耦合到F1A1态
水分子f态超快动力学时间分辨光电子能谱研究
No full text本文利用双光子激发和时间分辨的光电子成像技术研究了水分子F态的超快动力学.这是首次对水分子F态进行时间分辨的实验研究.水(重水)分子F1A1和F1B1态的寿命分别为1.0±0.3(1.9±0.4)和10±3(30±10)皮秒.我们提出F1A1态主要通过非绝热耦合内转换到D态,而F1B1态通过科里奥利相互作用耦合到F1A1态
