Abstract
Triacetone triperoxide (TATP) is a highly volatile and extremely dangerous peroxide-based explosive synthesized from readily accessible precursor chemicals. Due to its non-nitro composition, TATP evades most conventional field-detection systems. In this work, we investigate the potential of Ti(3)C(2)O(2) and Ti(3)C(2)F(2) MXene monolayers as portable, low-power sensing platforms for TATP vapor detection using density functional theory (DFT) coupled with non-equilibrium Green's function (NEGF) transport calculations. Three adsorption configurations (parallel and two orthogonal orientations) were systematically examined. TATP is adsorbed onto the surfaces of both MXenes via a multi-point hydrogen-bonding mechanism. This interaction yields net adsorption energies of - 0.45 eV and - 0.37 eV for Ti(3)C(2)O(2) and Ti(3)C(2)F(2), respectively. Density-of-states (DOS) and eigenstate analyses reveal HOMO-level pinning near the Fermi energy on Ti(3)C(2)O(2), enabling detectable current modulation at low bias. Transport simulations yield currents on the order of 10 µA at 0.1 V, at which relative current changes are measurable and amount to 3.7% for Ti(3)C(2)F(2) and 1% for Ti(3)C(2)O(2). The involvement of TATP's HOMO in the transport window for Ti(3)C(2)O(2) at elevated bias provides an additional sensing mechanism. Our findings suggest that both Ti(3)C(2)O(2) and Ti(3)C(2)F(2) MXenes are promising building blocks for portable, resistive TATP detectors.