Communication Issue
C60 as a metal-free catalyst for lithium-oxygen batteries
Nano Research 2024, 17 (5): 3982-3987
Published: 01 December 2023
Abstract PDF (2.9 MB) Collect

Carbon materials have shown significant potential as catalysts for lithium-oxygen batteries (LOBs). However, the intrinsic carbon sites are typically inert, necessitating extensive modifications and resulting in a limited density of active sites. Here we present C60 as a metal-free cathode catalyst for LOBs, using density functional theory calculations and experimental verifications. The lithiation reactions on the pristine carbon sites of C60 are energetically favorable due to its curved π-conjugation over the pentagon–hexagon networks. The kinetic analysis specifically reveals low energy barriers for Li2O2 decomposition and Li diffusion on C60. Consequently, C60 exhibits significantly higher catalytic activity than typical carbon materials such as graphene and carbon nanotubes. Our electrochemical measurements validate the predictions, notably demonstrating that the intrinsic activity of C60 is comparable to that of noble metals.

Research Article Issue
Simultaneous diffusion of cation and anion to access N, S co-coordinated Bi-sites for enhanced CO2 electroreduction
Nano Research 2021, 14 (8): 2790-2796
Published: 05 January 2021
Abstract PDF (30.8 MB) Collect

Developing highly active single-atom sites catalysts for electrochemical reduction of CO2 is an effective and environmental-friendly strategy to promote carbon-neutral energy cycle and ameliorate global climate issues. Herein, we develop an atomically dispersed N, S co-coordinated bismuth atom sites catalyst (Bi-SAs-NS/C) via a cation and anion simultaneous diffusion strategy for electrocatalytic CO2 reduction. In this strategy, the bonded Bi cation and S anion are simultaneously diffused into the nitrogen-doped carbon layer in the form of Bi2S3. Then Bi is captured by the abundant N-rich vacancies and S is bonded with carbons support at high temperature, formed the N, S co-coordinated Bi sites. Benefiting from the simultaneous diffusion of Bi and S, different electronegative N and S can be effectively co-coordinated with Bi, forming the uniform Bi-N3S/C sites. The synthesized Bi-SAs-NS/C exhibits a high selectivity towards CO with over 88% Faradaic efficiency in a wide potential range, and achieves a maximum FECO of 98.3% at -0.8 V vs. RHE with a current density of 10.24 mA·cm-2, which can keep constant with negligible degradation in 24 h continuous electrolysis. Experimental results and theoretical calculations reveal that the significantly improved catalytic performance of Bi-SAs-NS/C than Bi-SAs-N/C is ascribed to the replacement of one coordinated-N with low electronegative S in Bi-N4C center, which can greatly reduce the energy barrier of the intermediate formation in rate-limiting step and increase the reaction kinetics. This work provides an effective strategy for rationally designing highly active single-atom sites catalysts for efficient electrocatalysis with optimized electronic structure.

Total 2