Unconventional Photoconversion from In‐Plane 2D Heterostructures of 2D Transition Metal Carbides/Semiconductors

Abstract

2D transition metal carbides/nitrides (MXenes) are thought of promising photothermal materials due to their broadband localized surface plasma resonance (LSPR) and attractive electromagnetic interference (EMI) properties. However, the weak oxidation resistance and unclear photothermal mechanism of MXenes impede their photothermal modulations. Herein, the in‐plane 2D Ti3C2/TiO2 heterostructures are fabricated by partial oxidation and an unconventional photothermal effect under near infrared irradiation, even if the oxidation compromises the EMI and LSPR capacities, is demonstrated. Such performance is ascribed to the faster transfer of photoexcited electrons across the seamless in‐plane Ti3C2/TiO2 heterointerface than the reported out‐of‐plane one, and the 1–2 orders of magnitude faster relaxation processes of electrons than the ground bleaching in the Original MXene. These experimental results are well‐supported by theoretical calculations. The conceptual advances broaden the fundamental understanding of the photoconversion of MXenes, which would be extended into a variety of applications, such as biomedical therapy, photosynthesis, and photovoltaics.

Strain engineering of electrocatalysts for hydrogen evolution reaction

“…The fact that strain alone is not sufficient to activate the inert base of TMDs is also highlighted. The emerging transition metal carbon/nitrides (MXenes) with tunable band gap properties and excellent mechanical strength are candidates for HER catalysts, 98,99 but few studies were reported so far. The O* surface functional groups of MXenes are the active sites of HER and the strong interaction between H atoms and O* limits the HER activity.…”

Efficient photothermal conversion of MXenes and their application in biomedicine

“…The hot electrons are formed from the excitation of the occupied state to the unoccupied state and then converted into heat energy. 112,113 However, Zhang et al 114 pointed out that the weak oxidation resistance and unclear photothermal mechanism of MXenes hindered their photothermal modulation. They fabricated in-plane two-dimensional Ti 3 C 2 /TiO 2 heterostructures by partial oxidation, and demonstrated an unconventional photothermal effect under NIR irradiation, that is, oxidation damaged the LSPR capability.…”

High-Density Dual-Structure Single-Atom Pt Electrocatalyst for Efficient Hydrogen Evolution and Multimodal Sensing

“…Figure a illustrates a schematic diagram showing the formation of vacancy defects on Ti 3 C 2 and the subsequent insertion of Pt atoms. Briefly, the 2D Ti 3 C 2 nanosheets were fabricated by our previously reported methods. , During this procedure, some oxygen-containing termination groups were attached to the surface of Ti 3 C 2 , including −OH and −O groups. After that, a low-temperature hydrothermal treatment was utilized to create vacancies for immobilizing the Pt atoms.…”