Preparation of Ti₃C₂T_x MXene‐Derived Quantum Dots with White/Blue‐Emitting Photoluminescence and Electrochemiluminescence

Abstract

MXene‐derived quantum dots (MQDs) have begun to attract much attention recently, but their most attractive features (i.e., optical properties) are still explored less than expected. In the present work, Ti3C2Tx MQDs with solvent‐determined optical characteristics and size distributions are prepared through solvothermal treatment of Ti3C2Tx nanosheets in various solvents. White‐emitting photoluminescence (PL) under 365 nm UV irradiation is obtained in dimethyl sulfoxide (DMSO), while blue in dimethylformamide (DMF) and ethanol, respectively. Moreover, the average diameters and quantum yields of the MQDs are 3.3 ± 0.2 nm and 10.7%; 2.5 ± 0.2 nm and 6.9%; as well as 1.8 ± 0.1 nm and 4.1% in DMF, ethanol, and DMSO, respectively. Interestingly, among a variety of metal ions, Fe3+ shows specific quenching effect toward the PL of the MQDs in DMF rather than in the other two. Moreover, electrochemiluminescence of the MQDs is observed using persulfate as coreactant for the first time. The possible mechanisms are discussed based on the combined influences of polarity, oxidation effect, and boiling point of the different solvents and the various characterizations.

High‐Performance Electrocatalytic Conversion of N2 to NH3 Using Oxygen‐Vacancy‐Rich TiO2 In Situ Grown on Ti3C2Tx MXene

“…Preparation of TiO 2 /Ti 3 C 2 T x Nanosheets : The MXene nanosheets were obtained via the previously reported HF‐etching method (more detailed description can be found in the Supporting Information). Then, 0.15 g Ti 3 C 2 T x MXene was dispersed with 15 mL ethanol.…”

Electrogenerated Chemiluminescence and Electroluminescence of N‐Doped Graphene Quantum Dots Fabricated from an Electrochemical Exfoliation Process in Nitrogen‐Containing Electrolytes

“…[21][22][23][24][25][26][27] ECL has also been reported in several light-emitting applications, where solid-state devices utilizing traditional ECL luminophores exhibited highly efficient, low-voltage operation. [28][29][30][31] The first example of ap olymer light-emitting electrochemical cell (LEC) was introduced in 1995. [32] Unlike traditional LEDs that often require many electron and hole transport layers, LECs typicallyc onsist of as ingle light-emitting layer containing both the luminophore (normally ap olymer) and electrolyte sandwiched between an anode and acathode.…”

MXene Quantum Dot/Polymer Hybrid Structures with Tunable Electrical Conductance and Resistive Switching for Nonvolatile Memory Devices

“…The obtained Ti 3 C 2 T x MXene was transformed into MQDs by hydrothermal reaction. [26,29] Scanning electron microscopy images of Ti 3 AlC 2 MAX and Ti 3 C 2 T x MXene are shown in Figures S1a,b, Supporting Information. After the etching of HF, the bulk MAX disappears and the layered accordion-like MXene is produced.…”