Intrinsic Polarized Electric Field Induces a Storing Mechanism to Achieve Energy Storing Catalysis in V 2 C MXene.

Efficient storage and separation of holes and electrons pose significant challenges for catalytic reactions, particularly in the context of single-phase catalysis. Herein, V ₂ C MXene, with its intrinsic polarized electric field, successfully overcomes this obstacle. To enhance hole storage, a multistep etching process is employed under reducing conditions to control the content of surface termination groups, thus exposing more defective active sites. The intrinsically polarized electric field confines holes to the surface of the layer and free electrons within the layer, leading to a lag in e ^- release compared to h ⁺ . The quantities of stored holes and electrons are measured to be 18.13 µmol g ^-1 and 106.37 µmol g ^-1 , respectively. Under dark, V ₂ C demonstrates excellent and stable dark-catalytic performance, degrading 57.91% of tetracycline (TC 40 mg L ^-1 ) and removing 23% of total organic carbon (TOC) after 140 min. In simulated sunlight and near-infrared light, the corresponding degradation rates reach 72.24% and 79.54%, with corresponding TOC removal rates of 49% and 48%, respectively. The hole and electron induced localized surface plasmon resonance (LSPR) effects contribute to a long-lasting and enhanced broad-spectrum mineralization of V ₂ C MXene. This study provides valuable insights into the research and application of all-weather MXene energy storage catalytic materials.
(© 2023 Wiley-VCH GmbH.)