Noble metal decorated Ti₃C₂T_x MXene for room temperature SO₂ detection

This paper presents an in-depth investigation into the synthesis and characterization of Ti₃C₂Tₓ MXene and its noble metal-decorated variants (Ti₃C₂Tₓ-Ag and Ti₃C₂Tₓ-Au), underscoring their viability for the fabrication of high-performance SO₂ sensors. A self-reduction approach was employed to decorate Ti₃C₂T_x MXene with noble metals, and comprehensive characterization techniques enabled a detailed analysis of their properties. The formation of multilayered, and delaminated Ti₃C₂T_x and its successful decoration with Ag and Au nanoparticles (NPs) was confirmed using X-ray diffraction (XRD) analysis. The accordion-like morphology of multilayered Ti₃C₂T_x and transparent sheet-like structure were observed via field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). SO₂ sensing measurements revealed that Ti₃C₂T_x, along with its Ag- and Au-decorated Ti₃C₂T_x, demonstrated room-temperature SO₂ sensing with rapid response and recovery times. The loading of noble metals significantly improved sensitivity, with Ag-Ti₃C₂T_x showing the highest response. Density functional theory (DFT) calculations were performed to elucidate the mechanism underlying the enhanced sensitivity following noble metal decoration. The study results forecast a significant contribution to the development of Ti₃C₂T_x MXene for gas sensing applications.