The change in dislocation configuration ahead of a loaded crack tip before and after charging with hydrogen was in situ investigated in TEM using a special constant deflection loading device The results showed that hy...The change in dislocation configuration ahead of a loaded crack tip before and after charging with hydrogen was in situ investigated in TEM using a special constant deflection loading device The results showed that hydrogen could facilitate dislocation emission, multiplication and motion The change in displacement field ahead of a loaded notch tip for a bulk specimen before and after charging with hydrogen was in situ measured by the laser moire interferometer technique. The results showed that hydrogen could enlarge the plastic zone and increase the plastic strain The in situ observation in TEM showed that when hydrogen-enhanced dislocation emission and motion reached a critical condition, a nanocrack of hydrogen-induced cracking ( HIC) would nucleate in the dislocation-free zone (DFZ) or at the main crack tip. The reasons for hydrogen-enhanced dislocation emission, multiplication and motion, and the mechanisms of nucleation of HIC have been展开更多
Despite being technically possible, splitting water to generate hydrogen is practically unfeasible, mainly because of the lack of sustainable and efficient earth-abundant catalysts for the hydrogen-evolution reaction ...Despite being technically possible, splitting water to generate hydrogen is practically unfeasible, mainly because of the lack of sustainable and efficient earth-abundant catalysts for the hydrogen-evolution reaction （HER）. Herein, we report a durable and highly active electrochemical HER catalyst based on defect-rich TiO2 nanoparticles loaded on Co nanoparticles@N-doped carbon nanotubes （D-TiOdCo@NCT） synthesized by electrostatic spinning and a subsequent calcining process. The ultrasmall TiO2 nanoparticles are 1.5-2 nm in size and have a defect-rich structure of oxygen vacancies. D-TiO2/Co@NCT exhibits excellent HER catalytic activity in an acidic electrolyte （0.5 M H2SO4）, with a low onset potential of -57.5 mV （1 mA·cm^-2）, a small Tafel slope of 73.5 mV·dec^-1, and extraordinary long-term durability. X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and theoretical calculations confirm that the Ti3. defect-rich structure can effectively regulate the catalytic activity for electrochemical water splitting.展开更多
基金Project supported by the National Natural Science Foundation of China and the State Key Laboratory of Corrosion and Protection of Metal.
文摘The change in dislocation configuration ahead of a loaded crack tip before and after charging with hydrogen was in situ investigated in TEM using a special constant deflection loading device The results showed that hydrogen could facilitate dislocation emission, multiplication and motion The change in displacement field ahead of a loaded notch tip for a bulk specimen before and after charging with hydrogen was in situ measured by the laser moire interferometer technique. The results showed that hydrogen could enlarge the plastic zone and increase the plastic strain The in situ observation in TEM showed that when hydrogen-enhanced dislocation emission and motion reached a critical condition, a nanocrack of hydrogen-induced cracking ( HIC) would nucleate in the dislocation-free zone (DFZ) or at the main crack tip. The reasons for hydrogen-enhanced dislocation emission, multiplication and motion, and the mechanisms of nucleation of HIC have been
基金We thank the Fundamental Research Funds for the Central Universities （No. D2153880）, Project of Public Interest Research and Capacity Building of Guangdong Province （No. 2014A010106005） and the National Natural Science Foundation of China （No. 51502096）.
文摘Despite being technically possible, splitting water to generate hydrogen is practically unfeasible, mainly because of the lack of sustainable and efficient earth-abundant catalysts for the hydrogen-evolution reaction （HER）. Herein, we report a durable and highly active electrochemical HER catalyst based on defect-rich TiO2 nanoparticles loaded on Co nanoparticles@N-doped carbon nanotubes （D-TiOdCo@NCT） synthesized by electrostatic spinning and a subsequent calcining process. The ultrasmall TiO2 nanoparticles are 1.5-2 nm in size and have a defect-rich structure of oxygen vacancies. D-TiO2/Co@NCT exhibits excellent HER catalytic activity in an acidic electrolyte （0.5 M H2SO4）, with a low onset potential of -57.5 mV （1 mA·cm^-2）, a small Tafel slope of 73.5 mV·dec^-1, and extraordinary long-term durability. X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and theoretical calculations confirm that the Ti3. defect-rich structure can effectively regulate the catalytic activity for electrochemical water splitting.
