The search for active,stable,and cost-effective electrocatalysts for hydrogen evolution reaction(HER)is desirable,but it remains a great challenge in the overall water splitting.Here,we report the synthesis of nickel ...The search for active,stable,and cost-effective electrocatalysts for hydrogen evolution reaction(HER)is desirable,but it remains a great challenge in the overall water splitting.Here,we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon(Ni-B)via a simple,yet scalable,two-step chemical reduction–annealing strategy.The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV(in 1 mol L^–1 KOH)at current densities of 10 and 40 mA cm^?2,respectively,indicating an exceedingly good electrocatalytic activity in the HER.More importantly,Ni-B maintains a current density of 7.6 mA cm^-2 at an overpotential of 0.15 V for 20 h in the durability test.The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni,which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties.展开更多
The permeation enhancing activity of Azone for ketoprofen through excised cavia skins was investigated using Franz diffusion cell. The possible hydrogen-bonded complexes formed between ketoprofen and the model molecul...The permeation enhancing activity of Azone for ketoprofen through excised cavia skins was investigated using Franz diffusion cell. The possible hydrogen-bonded complexes formed between ketoprofen and the model molecule of Azone as azacyclopentane-2-one were fully optimized at the B3LYP/6-311＋＋G＊＊ level. The intermolecular hydrogen-bonding interactions were calculated using the B3LYP/6-311＋＋G＊＊, B3LYP/6-311＋＋G（2df, 2p）, MP2（full）/6-311＋＋G＊＊ and MP2（full）/6-311＋＋G（2df, 2p） methods, respectively. The results show that the steady-state permeation rate of ketoprofen through excised cavia skins enhances over 9 times in the solvent with 2% Azone as compared with the solvent without Azone. The stable O–H…O=C and N–H…O=C hydrogen-bonded complexes could exist between azacyclopentane and ketoprofen. The hydrogen-bonding interaction energy follows the order of（a） 〉（b） 〉（c） 〉（d） 〉（g）〉（e） 〉（h） 〉（f）. The formation of the complexes leads to the change of the conformation and molecular polarity of ketoprofen, and thus causes a better percutaneous permeation for the drug. The analyses of AIM（atom in molecule） and shift of electron density were used to further reveal the nature of the enhancing permeation activity of Azone for ketoprofen. The investigations of the temperature and solvent effects confirm that ketoprofen might enter into the skin by means of the Azone complex.展开更多
基金supported by the National Natural Science Foundation of China(21573083)the 1000 Young Talent(to Deli Wang)initiatory financial support from Huazhong University of Science and Technology(HUST)~~
文摘The search for active,stable,and cost-effective electrocatalysts for hydrogen evolution reaction(HER)is desirable,but it remains a great challenge in the overall water splitting.Here,we report the synthesis of nickel boron nanoparticles supported on Vulcan carbon(Ni-B)via a simple,yet scalable,two-step chemical reduction–annealing strategy.The results of the electrochemical measurements suggest that the overpotentials of Ni-B-400 are 114 and 215 mV(in 1 mol L^–1 KOH)at current densities of 10 and 40 mA cm^?2,respectively,indicating an exceedingly good electrocatalytic activity in the HER.More importantly,Ni-B maintains a current density of 7.6 mA cm^-2 at an overpotential of 0.15 V for 20 h in the durability test.The excellent HER activity of Ni-B-400 is derived from the small particle size and the expanded lattice of Ni,which can optimize the hydrogen absorption energy and enhance the electrocatalytic properties.
基金Supported by Natural Science Foundation of Shanxi Province(No.2012011007-5)the application and innovation project in police(No.2011YYCXSXST016)
文摘The permeation enhancing activity of Azone for ketoprofen through excised cavia skins was investigated using Franz diffusion cell. The possible hydrogen-bonded complexes formed between ketoprofen and the model molecule of Azone as azacyclopentane-2-one were fully optimized at the B3LYP/6-311＋＋G＊＊ level. The intermolecular hydrogen-bonding interactions were calculated using the B3LYP/6-311＋＋G＊＊, B3LYP/6-311＋＋G（2df, 2p）, MP2（full）/6-311＋＋G＊＊ and MP2（full）/6-311＋＋G（2df, 2p） methods, respectively. The results show that the steady-state permeation rate of ketoprofen through excised cavia skins enhances over 9 times in the solvent with 2% Azone as compared with the solvent without Azone. The stable O–H…O=C and N–H…O=C hydrogen-bonded complexes could exist between azacyclopentane and ketoprofen. The hydrogen-bonding interaction energy follows the order of（a） 〉（b） 〉（c） 〉（d） 〉（g）〉（e） 〉（h） 〉（f）. The formation of the complexes leads to the change of the conformation and molecular polarity of ketoprofen, and thus causes a better percutaneous permeation for the drug. The analyses of AIM（atom in molecule） and shift of electron density were used to further reveal the nature of the enhancing permeation activity of Azone for ketoprofen. The investigations of the temperature and solvent effects confirm that ketoprofen might enter into the skin by means of the Azone complex.
