Electromagnetic interference shielding with 2D transition metal carbides (MXenes)

Abstract

Materials with good flexibility and high conductivity that can provide electromagnetic interference (EMI) shielding with minimal thickness are highly desirable, especially if they can be easily processed into films. Two-dimensional metal carbides and nitrides, known as MXenes, combine metallic conductivity and hydrophilic surfaces. Here, we demonstrate the potential of several MXenes and their polymer composites for EMI shielding. A 45-micrometer-thick Ti3C2Tx film exhibited EMI shielding effectiveness of 92 decibels (>50 decibels for a 2.5-micrometer film), which is the highest among synthetic materials of comparable thickness produced to date. This performance originates from the excellent electrical conductivity of Ti3C2Tx films (4600 Siemens per centimeter) and multiple internal reflections from Ti3C2Tx flakes in free-standing films. The mechanical flexibility and easy coating capability offered by MXenes and their composites enable them to shield surfaces of any shape while providing high EMI shielding efficiency.

Transparent, conductive solution processed spincast 2D Ti2CTx (MXene) films

“…The sheet conductivity of our 100 nm Ti 2 CT x films is 5250 S/cm which is slightly lower than that equally thick Ti 3 C 2 T x films (6450 S/cm) [32]. It is higher than that of other Ti 3 C 2 T x films reported in previous MXene work [8,21], or reduced-GO [40].…”

“…However, to date, by far the most studied remains the first MXene discovered: Ti 3 C 2 T x [13]. This material has shown outstanding performance as an electrode material for supercapacitors and Li battery electrodes [17][18][19][20], electromagnetic shielding [21][22][23], among a slew of other applications [24,25].…”

In Situ Formed Protective Barrier Enabled by Sulfur@Titanium Carbide (MXene) Ink for Achieving High‐Capacity, Long Lifetime Li‐S Batteries

“…By selectively etching the A atomic layer from the parent MAX phase (where M represents an early transition metal, A is typically aluminum (Al) or gallium, and X is C and/or N) or other ternary layered ceramics, MXenes terminated with abundant functional groups, such as oxygen (—O), hydroxyl (—OH), and/or fluoride (—F), are obtained, which can be expressed via the formula of M n +1 X n T x (where n = 1, 2, or 3 and T is a terminating group) 32, 33, 34. In the MXene family, titanium carbide (Ti 3 C 2 T x ) is the most intensively studied one and has exhibited good performances in supercapacitors,35, 36, 37, 38 Li (Na)‐ion batteries,39, 40 antibacterial coatings,41 electromagnetic‐interference shielding,42 etc. The metallic conductivity35, 37 coupled with rich surface chemistry renders Ti 3 C 2 T x an excellent host for trapping the Li 2 S x , as supported both by the density functional theory (DFT) studies and experiments 43, 44, 45.…”

Electronic properties and applications of MXenes: a theoretical review

“…Experimentally, MXenes have already found applications as transparent conductors [18][19][20], field effect transistors [21], supercapacitors [22][23][24], Li ion batteries [25,26], electromagnetic interface shielders [27], fillers in polymeric composites [28], hybrid nanocompositites [29], purifiers [30,31], dual-responsive surfaces [32], suitable substrates for dyes [33], catalysts [34,35], promising materials for methane storage [36], and photocatalysts for hydrogen production [37], as well as being ceramic biomaterials with high photothermal conversion efficiency for cancer therapy [38]. Theoretically, many applications have been proposed for MXenes in electronic [39][40][41][42][43], magnetic [44][45][46][47][48], optical [49,50], thermoelectric [51][52][53][54][55][56], and sensing devices [57], as well as being new potential materials for catalytic and photocatalytic reactions [58][59][60]…”