Cobalt oxide-coated N- and B-doped graphene hollow spheres as bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions

Abstract

Co3O4-coated N- and B-doped graphene hollow spheres synthesized by a simple and scalable method have been used as electrocatalysts for the ORR and the OER, demonstrating higher electrochemical performance and better durability than commercial Pt/C and RuO2/C, respectively.

An Asymmetric‐Electrolyte Zn−Air Battery with Ultrahigh Power Density and Energy Density

“…Besides, the AEZAB also shows dominant performance advantages over the most predominant ZABs reported previ-ously, [16,32,[56][57][58][59][60][61][62] further verifying a suitable asymmetric electrolyte in ZAB can bring forth remarkable improvement in performance of the ZAB. It should be pointed out that the electrolyte in both chamber did show remarkable impaction on the battery performance.…”

Fabrication Sandwich‐Like V2O5 Nanosheets Anchor in Graphene Towards High Energy Lithium Cathode Materials

“…The intensity of C−C bond is much higher than that of C−O and C=O/O−C=O bonds, demonstrating the successful reduction of GO into graphene. The XPS spectrum of O 1s can be fitted by three peaks corresponding to V−O−V (530.1 eV), V−OH (531.2 eV) and C=O/C−O (533.0 eV), respectively (Figure (c)) ,. Two peaks of V 2p (517.2 and 524.7 eV) can be detected, which are the characteristics of V 5+ in V 2 O 5 (Figure d) .…”

Functional Species Encapsulated in Nitrogen‐Doped Porous Carbon as a Highly Efficient Catalyst for the Oxygen Reduction Reaction

“…It is noteworthy that when both cobalt and nitrogen were introduced into the catalyst, the ORR activity of the catalystC o-W-C/N tremendously improved in terms of ar emarkably positively shifted E 1/2 ,w hich is 94 and 63 mV more positive than that of the catalysts W-C and Co-N/ C, respectively.T his is ascribed to the coexistence of rich Co-N/ Ca ctive sites and carbide species. [15] To gain deep insights into the ORR mechanism of Co-W-C/N, rotating ring-disc electrode (RRDE) measurements werec onducted at room temperature in O 2 -sa-turated0 .1 m KOH solution. What's interesting is that the ORR activity of Co-W-N/C after etching with 1 m hydrochlorica cid is significantly degraded.…”

“…[4] Traditionally,p latinum-based materials are regarded as the most effective catalysts for the ORR, taking into consideration their high activityt hrough the effective four-electron transfer pathway leading from oxygen to water. [7,8] Over the past severald ecades, tremendous efforts have been devoted to the rational design and synthesis of NPMCs as alternatives to Pt-based materials, including heteroatom-doped (N, P, or S) carbonaceousm aterials, [9][10][11][12] non-precious metal oxides, [13][14][15] carbides, [16][17][18] and transition-metal-N/C composites. [5,6] Thed evelopment of non-precious metal catalysts (NPMCs) with both excellent activity and high stability, therefore, is pivotal to address this issue.…”

“…[5,6] Thed evelopment of non-precious metal catalysts (NPMCs) with both excellent activity and high stability, therefore, is pivotal to address this issue. [7,8] Over the past severald ecades, tremendous efforts have been devoted to the rational design and synthesis of NPMCs as alternatives to Pt-based materials, including heteroatom-doped (N, P, or S) carbonaceousm aterials, [9][10][11][12] non-precious metal oxides, [13][14][15] carbides, [16][17][18] and transition-metal-N/C composites. [19][20][21] Among the several promisingc atalysts, transition metal carbide materials are extremely attractive owingt ot heir highd urability,f avorable conductivity,a nd superior corrosionr esistance.…”