ABSTRACT
Designing a multifunctional electrocatalyst to produce H2 from water, urea, urine, and wastewater, is highly desirable yet challenging because it demands precise Fermi-engineering to realize stronger π-donation from O 2p to electron(e- )-deficient metal (t2g ) d-orbitals. Here a Sr-induced phase transformed ß-FeOOH/α-Ni(OH)2 catalyst anchored on Ni-foam (designated as pt-NFS) is introduced, where Sr produces plenteous Fe4+ (Fe3+ â Fe4+ ) to modulate Fermi level and e- -transfer from e- -rich Ni3+ (t2g )-orbitals to e- -deficient Fe4+ (t2g )-orbitals, via strong π-donation from the π-symmetry lone-pair of O bridge. pt-NFS utilizes Fe-sites near the Sr-atom to break the HâOâH bonds and weakens the adsorption of *O while strengthening that of *OOH, toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Invaluably, Fe-sites of pt-NFS activate H2 -production from urea oxidation reaction (UOR) through a one-stage pathway which, unlike conventional two-stage pathways with two NH3 -molecules, involves only one NH3 -molecule. Owing to more suitable kinetic energetics, pt-NFS requires 133 mV (negative potential shift), 193 mV, ≈1.352 V, and ≈1.375 V versus RHE for HER, OER, UOR, and human urine oxidation, respectively, to reach the benchmark 10 mA cm-2 and also demonstrates remarkable durability of over 25 h. This work opens a new corridor to design multifunctional electrocatalysts with precise Fermi engineering through d-band modulation.
ABSTRACT
OBJECTIVE: To study the expression of Skp2 gene (s-phase kinase associated protein 2) in the pathological scars and its relationship with p27kip1 level and to investigate its role and its probable mechanism in the pathogenesis of abnormal scars. METHODS: Immunohistochemical technique was performed to detect the expression and distribution of Skp2 and p27kip1 protein in hypertrophic scar (42 cases), keloid (18 cases), normal scar (40 cases) and normal skin (50 cases), statistics was used to analyze the data. RESULTS: The positive rate of Skp2 and p27kip1 protein expression was not statistically different between the hypertrophic scar and keloid (P > 0.05), while they were all remarkably significant in comparison between normal scar and abnormal scar (P < 0.05). In pathological scar the protein of Skp2 and p27kip1 showed a strong inverse correlation (P < 0.01). CONCLUSION: The result indicated that the expression of Skp2 was increased and it may lead to decrease p27kip1 level in the hypertrophic scar and keloid, Skp2 overexpression might play an important role in the proliferation of fibroblasts and in the pathogenesis of pathological scar by adjusting the regulation of cyclins such as p27kip1.