RESUMEN
At present, electrochemical CO2 reduction has been developed towards industrial current density, but the high faradaic efficiency at wide potential range or large current density is still an arduous task. Therefore, in this work, the highly exposed Ni single atoms (NiNCR-0.72) was synthesized through simple metal organic frameworks (MOFs)-derived method with SiO2 protection strategy. The obtained catalyst keeps CO faradaic efficiency (FECO) above 91 % under the wide potential range, and achieves a high FECO of 96.0 % and large CO partial current density of -206.8 mA cm-2 at -0.7 V in flow cell. The experimental results and theoretical calculation disclose that NiNCR-0.72 possesses the robust structure with rich mesopore and more highly exposed Ni-N active sites under SiO2 protection, which could facilitate CO2 transportation, lower energy barrier of CO2 reduction, and raise difficulty of hydrogen evolution reaction. The protection strategy is instructive to the synthesis of other MOFs-derived metal single atoms.
RESUMEN
Lithium metal batteries are regarded as promising candidates for next-generation energy storage systems. However, their anodes are susceptible to interfacial instability due to significant volume changes, which significantly impacts the cycle life of lithium metal batteries. Here, a rapid method for the fabrication of 3D-hosts with interface modified layers is reported. A simple infiltration and heating process enables the transformation of copper foam into Zn-BDC-modified copper foam within 1 min, rendering it suitable for use as a current collector for lithium metal anodes. The Zn-BDC nanosheets with high lithiophilicity are uniformly distributed on the surface of the current collector, facilitating the uniform deposition of lithium and reducing the volume change. Consequently, the half cell exhibits a remarkably low overpotential (26 mV) at a current-density of 4 mA cm-2 and is cycled stably for 1000 h. Furthermore, it demonstrates a significant enhancement in performance in the LiFePO4 full cell. This study provides a crucial reference on the connection between the interfacial modification of the current collector and the lithium deposition behavior, which promotes the practicalization of lithium metal anodes.