Electrodeposition of Er-Ni Alloy Film in Dimethylsulfoxide

The cyclic voltammetry and chronoamperometry were used to investigate the electrochemical behaviors of Er(Ⅲ) and Ni(Ⅱ) in LiClO 4 DMSO(dimethylsufoxide) system on Pt and Cu electrodes. Experimental results indicated that the reduction of Er(Ⅲ) to Er and Ni(Ⅱ) to Ni were irreversible in one step on Pt and Cu electrodes. The diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01 mol·L -1 ErCl 3 -0.1 mol·L -1 LiClO 4 DMSO system at 303K were 1.47×10 -10 m 2·s -1 and 0.108 respectively, and the diffusion coefficient and electron transfer coefficient of Ni(Ⅱ) in 0.01 mol·L -1 NiCl 2-0.1 mol·L -1 LiClO 4 DMSO system at 303K were 3.38×10 -10 m 2·s -1 and 0.160 respectively. The homogeneous, strong adhesive Er Ni alloy films with metallic lu- stre was prepared by potentiostatic electrolysis on Cu electrode in ErCl 3 NiCl 2 LiClO 4 DMSO system at -1.90～ -2.55 V (vs SCE).

Improved photocatalytic performance of acetaldehyde degradation via crystal plane regulation on truncated octahedral CeO_(2)

In this study,the truncated octahedral CeO_(2)(CeO_(2)-to)with special morphology was prepared by the solvothermal method with oleic acid(OA)and oleamine(OM)as the morphology-directing agents.High-resolution transmission electron microscopy(HRTEM)results show that CeO_(2)-to exposes composite{100}and{111}facets,while CeO_(2)cubic(CeO_(2)-c)and CeO_(2)octahedral(CeO_(2)-o)only expose single crystal facets of{100}plane and{111}plane,respectively.Interestingly,this CeO_(2)-to photocatalyst exhibits remarkable photooxidation performance of gaseous acetaldehyde(CH_(3)CHO)degradation,in which CO_(2)generation value reaches 1.78 and 7.97-times greater than that of CeO_(2)-c and CeO_(2)-o,respectively.In addition,the active species trapping experiment signifies that superoxide(·O_(2)^(-))and holes(h^(+))are the main reactive substances during the CH_(3)CHO degradation process,and the electron paramagnetic resonance(EPR)spectra indicates that the former is the major contributor.Notably,the electron transfer mechanism between CeO_(2)-to{100}and{111}facets and the surface oxygen adsorption ability are revealed via density functional theory(DFT)calculations.It is also confirmed that{100}facets are more conducive to the absorption of acetaldehyde than{111}facets.Finally,a reasonable mechanism for improved photocatalytic CH_(3)CHO degradation on CeO_(2)-to is proposed based on relevant experiments and DFT calculations.This study demonstrates that the systematic development of surface homojunction structured photocatalysts can efficiently increase the degradation activity for volatile organic compounds(VOCs).It also offers additional direction for optimizing the photocatalytic activity of other ceriumbased photocatalysts.

Enhanced n-Type Thermoelectric Performance of Conjugated Polymers Based on an Indandione-Terminated Quinoidal Unit through Comonomer Optimization

Comprehensive Summary Conjugated polymers(CPs)containing quinoidal units are promising in n-type organic thermoelectric materials because of their deep-positioned lowest unoccupied molecular orbital(LUMO)energy levels and planar conjugated backbones.Herein,three CPs have been synthesized by copolymerizing an indandione-terminated quinoidal unit with bithiophene derivatives.Owning to the high electron affinity of the indandione-terminated quinoidal unit,all polymers showed deep LUMO energy levels below-4.10 eV.Incorporating electron-withdrawing substituents(F or CN)on the bithiophene comonomer can further downshift the LUMO energy levels.As a result,a more efficient n-doping process can be realized when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine(N-DMBI)as the dopant.Ultimately,the polymer with CN substituents delivered the best thermoelectric performance with a power factor of up to 2.14μW·m^(−1)·K^(−2),because it possessed the lowest LUMO energy level among the three CPs.This work highlights that the modulation of LUMO energy level is an effective strategy to optimize the thermoelectric performance of CPs.

Theoretical Study of the Radical Scavenging Activity of Shikonin and Its Derivatives

A series of shikonin derivatives have been designed and their radical scavenging activity has been characterized by the B3LYP/6-31 ＋G（d） approach. The hydrogen bond properties of the studied structures were investigated using the atoms in molecules （AIM） theory. The calculated results reveal that the hydrogen bond is important for good scavenging activity. The introduction of electron-drawing （electron-donating） groups increases （decreases） the scavenging activities of radical and radical cations of shikonin derivatives. Shikonin derivatives appear to be good candidates for the single-electron-transfer mechanism, particularly for -N（CH3）2 derivative. Taking this system as an example, we present an efficient method for the investigation of radical scavenging activity from theoretical point of view. With the current work, we hope to highlight the radical scavenging activity of hydroxynaphtho- quinones derivatives and stimulate the interest for further studies and exploitation in pharmaceutical industry.

Mechanical Trapping of the Phlorin Intermediate

Trapping unstable intermediates for elucidating reaction mechanisms in chemistry presents a formidable challenge.There has long been a lack of direct evidence for key intermediates like the highly reactive phlorin leading to porphyrin.Here,we report a molecular-strain engineering(MSE)strategy that harnesses intramolecular strain to trap the native phlorin during porphyrin synthesis.By mechanically constraining its periphery,a phlorin stable towards oxidation was captured as an isolable intermediate and fully characterized.

Photoinduced electron transfer of [ Ru (bpy)_2 (4, 4'-dcbpy)]^(2+) with electron donors

Emission quenching of [Ru(bpy)2(4, 4'-dcbpy)] (PF6)2 (1) by benzenamine,4-[2-[5-[4-[4-dimethylamino]phenyl]-4,5-di-hydro-1-phenyl-1H-pyrazol-3-yl]-ethenyl]-N,N-dimetyl (2) or 1, 5-diphenyl-3-(2-phenothiazine)-2-pyrazoline (3) was observed. Measurements of the emission decay of 1 before and after addition of 2 or 3 by single photon counting technique con-finned the observations. The emission quenching of 1 by 2 or 3 was submitted to Stern-Volmer equation. It was calculated that the quenching rate constants (kq) are 5.5 × 109(mol/L)-1s-1 for 2 and 4.0 × 109(mol/L)-1s-1 for 3, respectively. These results indicated a character of dynamic quenching process. The singlet-state of 2 or 3 was also quenched by 1. The quenching behaviors did not conform to the Stern- Volmer equation and involved both static and dynamic quenching processes. The apparent quenching rate constant (kapp) was calculated to be 3 × 109 (mol/L)-1 for the interaction of excited 2 with 1, and 1.2 × 109 (mol/L)-1 for that of excited 3 with 1.