Heterogeneous Co@CoO composited P, N co-doped carbon nanofibers on carbon cloth as pH-tolerant electrocatalyst for efficient oxygen evolution

Facile Synthesis of Fe‐Doped CoO Nanotubes as High‐Efficient Electrocatalysts for Oxygen Evolution Reaction

“…The high-resolution XPS spectrum of Co 2p (Figure S8b, Supporting Information) still showed the characteristic peaks (780.6 and 796.4 eV) of Co 2þ , corresponding to CoO. [16] In addition, newly appeared peaks at 779.8 and 794.9 eV could be assigned to the signals of Co 2p 3/2 and Co 2p 1/2 derived from Co 3þ , which might be due to the partial oxidation of CoO to CoOOH during OER. [16,18] After the durability test, the binding energy of Fe 2p 2/3 (Figure S8c, Supporting Information) slightly shifted from 712.6 to 713.0 eV due to structural evolution, which indicates that more Fe atoms could be directly connected with the O atom.…”

“…From the high‐resolution XPS spectrum of Co 2 p (Figure 3b), two peaks that appeared at about 780.7 and 796.7 eV could be assigned to the characteristic signals of Co 2 p 3/2 and Co 2 p 1/2 , respectively, and the peaks around 785.7 and 802.6 eV were the corresponding satellite peaks, which were well matched with Co 2+ that came from CoO. [ 16 ] The high‐resolution XPS spectrum of Fe 2 p shown in Figure 3c could be divided into three peaks. Peaks at 712.7 and 718.6 eV were indexed to Fe 2 p 3/2 and the corresponding satellite peak, and the broad peak around 724.8 eV could be ascribed to Fe 2 p 1/2 , indicating that the Fe species of Fe‐doped CoO composites existed as the high oxidation state of Fe 3+ .…”

“…[ 16 ] In addition, newly appeared peaks at 779.8 and 794.9 eV could be assigned to the signals of Co 2 p 3/2 and Co 2 p 1/2 derived from Co 3+ , which might be due to the partial oxidation of CoO to CoOOH during OER. [ 16,18 ] After the durability test, the binding energy of Fe 2 p 2/3 (Figure S8c, Supporting Information) slightly shifted from 712.6 to 713.0 eV due to structural evolution, which indicates that more Fe atoms could be directly connected with the O atom. [ 23 ] Furthermore, stronger intensity of the peak at 532.8 eV could be observed from the O 1 s XPS spectrum after the stability test (Figure S8d, Supporting Information), indicating that the content of hydroxyl oxygen species in the sample increased.…”

Ni nanoparticles assembled on the surface of biomass-derived porous carbon as competitive candidates for the hydrogen evolution reaction

“…The synergistic effect between Ni nanoparticles offers rich active surface area and sites, thereby giving rise to prominent activity for HER in an alkaline medium. 45 Furthermore, the sharp lattice fringes of the Ni-PC are displayed in the HRTEM images. The lattice spacing of 0.203 nm matches well with the (111) plane of Ni (Fig.…”

Thein situformation of defective CoOOH catalysts from semi-oxidized Co for alkaline oxygen evolution reaction

“…For instance, recent research found that some unique treatments for the initial Co-based precatalyst could effectively enhance the nal performance. CoO nanostructures with abundant oxygen vacancies and heterogeneous Co/CoO electrocatalysts could both boost the catalytic activity and durability of the OER compared with standard CoO or Co. [32][33][34] To fully understand the in situ activation of Co-based compounds, detailed experimental work should be conducted to illustrate the atomic-level dynamics of their local coordination environment during the reaction by advanced instrumental techniques such as EXAFS and XANES. 35 Herein, we synthesized different phases of cobalt-based precatalysts (Co/GO, Co-CoO/GO and Co 3 O 4 /GO) by annealing the CoO x precursors in H 2 , Ar and air.…”