《International Journal of Hydrogen Energy》2019,44(42):23568-23579

A new class of ‘bubble-free’ alkaline electrolyzer with electrodes comprising of PTFE-based Gortex gas diffusion layers coated with catalysts, is described (PTFE = poly(tetrafluoroethylene)). At ≥80 °C (E^o_cell 1.18 V), the electrolyzers displayed the lowest cell onset potentials (≥1.28 V) yet reported, indicating that they exhibit the highest-known intrinsic efficiency when the influence of impedance is stripped out. The overpotentials at each electrode, particularly the oxygen-generating anode, were significantly diminished by the presence of the porous Gortex substrate, which exhibited a powerful ‘gas-philic’ capillary action (6.3 bar capillary pressure). The bubble-free process arose from preferential coalescence of newly-formed gases on the PTFE surfaces, where the capillary action of the Gortex continuously extracted them before they could nucleate bubbles. In so doing, observable bubble formation was avoided, along with the energy penalties associated with the formation and release of gas bubbles.  相似文献   

    

《International Journal of Hydrogen Energy》2020,45(15):8549-8557

PtSe₂ monolayer is previously predicted to be a two-dimensional water-splitting photocatalyst. However, the weak van der Waals (vdW) interaction between H₂O and the basal surface of PtSe₂ significantly undermines its photocatalytic water-splitting activities. In this work, we explore the possibility of various intrinsic defects of PtSe₂ in remedying this deficiency on the basis of first-principles calculations. It is interesting to find that the introduction of Pt@Se, Se@Pt, and Se interstitial defect not only fully retain the water redox abilities of pure PtSe₂ and realize spatial separation of photogenerated electrons and holes, but also can extend optical absorption range and absorption coefficients. Moreover, introduction of the three kinds of defects increase the initial weak vdW interactions between H₂O and the PtSe₂ surface to different extent. In particular, Pt@Se anti-site defect transform the initial weak vdW to strong chemical interaction between H₂O and PtSe₂ surface, and function as active reaction site. These insights demonstrate that introduction of intrinsic defects, especially the Pt@Se anti-site defect, are effective means for improving the photocatalytic water-splitting activities of PtSe₂ monolayer.  相似文献