Co single atoms and Co nanoparticle relay electrocatalyst for rechargeable zinc air batteries

Quasi-Solid-State Flexible Zn–Air Batteries with a Hydrophilic-Treated Co@NCNTs Array Electrocatalyst and PEO–PANa Electrolyte

“…Moreover, the average H 2 O 2 -yield of MoS 2 –Co@NCNTs–ER was less than 10% and the average value of electron transfer number was ∼3.8, indicating that it followed an efficient four-electron transfer ORR process (Figure S13b). In general, the Co–N x fraction is the main active site for O 2 adsorption reduction, and metal nanoparticles encapsulated in carbon nanotubes facilitate ORR by splitting O–O bonds in OOH* intermediates to form O* species. , XPS results confirm that the carbon nanotubes of MoS 2 –Co@NCNTs–ER contain a large amount of Co–N/Co–O and Co metal species, which are the main sources of their ORR activity, as confirmed by the higher half-wave potential of Co@NCNTs. However, the enhanced ORR activity of MoS 2 –Co@NCNTs–ER compared to Co@NCNTs was attributed to its improved hydrophilicity, and as mentioned previously, the contact angle of MoS 2 –Co@NCNTs–ER was significantly lower compared to Co@NCNTs (Figure c).…”

Metal–organic framework-derived Co single atoms anchored on N-doped hierarchically porous carbon as a pH-universal ORR electrocatalyst for Zn–air batteries

“…S18,† a typical CoN 4 configuration (a Co atom is anchored by four nitrogen atoms within the graphene substrate) serves as the active center for Co-SAs/N–C/rGO, whereas a CoNPs configuration (a Co cluster composed of four Co atoms within the graphene substrate) is employed as the reference site. 20,53,54 As illustrated in Fig. 6a, the free-energy paths towards ORR for Co-SAs/N–C/rGO were obtained, where *OOH, *O, and *OH species are regarded as oxygenated intermediates, and * signifies the adsorption site.…”

Modulation in the d Band of Ir by Core–Shell Construction for Robust Water Splitting Electrocatalysts in Acid

“…Until now, two principles are devoted to enhancing the OER performance of metallic Ir electrocatalysts, namely, (i) creating more exposed active sites guaranteed by the morphology − and (ii) tailoring the OER catalytic ability of the single active center depending on the electronic configuration. − Catalytic activity would be substantially increased via the combination of these two strategies. Accordingly, metallic Ir-based electrocatalysts with various morphologies, such as nanosheets, , nanocages, − and nanowires, , have shown superior acidic OER performance.…”