Heterostructuring 2D TiO2 nanosheets in situ grown on Ti3C2Tx MXene to improve the electrocatalytic nitrogen reduction

In this study, TiO2 nanosheets (NSs) grown in situ on extremely conductive Ti3C2Tx MXene to form TiO2/Ti3C2Tx MXene composites with abundant active sites are proposed to effectively achieve electrocatalytic NH3 synthesis. Electron transfer can be promoted by Ti3C2Tx MXene with high conductivity. Meanwhile, the TiO2 NSs in-situ formation can not only avoid Ti3C2Tx MXene microstacking but also enhance the surface specific area of Ti3C2Tx MXene. The TiO2/Ti3C2Tx MXene catalyst reaches a high Faradaic efficiency (FE) of 44.68% at ???0.75 V vs. RHE and a large NH3 yield of 44.17 ??g h???1 mg???1cat. at ???0.95 V, with strong electrochemical durability. 15N isotopic labeling experiments imply that the N in the produced NH3 originated from the N2 of the electrolyte. DFT calculations were conducted to determine the possible NRR reaction pathways for TiO2/Ti3C2Tx MXene composites. MXene catalysts combined with other materials have been rationally designed for efficient ammonia production under ambient conditions. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, TiO2 nanosheets (NSs) grown on highly conductive Ti3C2Tx MXene were proposed to achieve electrocatalytic NH3 synthesis. Ti3C2Tx MXene promoted electron transfer, while in-situ formation of TiO2 NSs prevented stacking and increased surface area. The TiO2/Ti3C2Tx MXene catalyst exhibited high efficiency and strong electrochemical durability, with the nitrogen in the produced NH3 originating from the electrolyte's N2.