Precious Metals Atomic Layer Deposited MXene Advanced Heterostructures for Clean Energy and Healthcare Applications

Abstract

The economic ramifications associated with the utilization of noble metals/precious metals such as Pt, Pd, Ir, Rh, and Ru are significant, as they are not only costly but also relatively scarce, with Ir being especially limited, given that its natural occurrence is estimated to be roughly one-tenth that of Pt and Ru, rendering its availability a crucial element in industrial electrocatalysis and sensing applications. In this regard, atomic layer deposition (ALD) emerges as a cutting-edge precision thin film technique that is increasingly recommended for industrial applications, as it provides atomic-level control over the deposition of even the rarest noble metals Ir, allowing for the placement of single metal atoms or clusters through a self-limiting growth process. We attempt to introduce a pragmatic approach towards the utilization of Ir precious metal, employing the ALD technique on the ever-expanding new 2D MXene family member, thereby facilitating the creation of a sophisticated Ir-ALD-MXene advanced multifunctional heterostructure that not only takes into account the cost and rarity of Ir but also aims to contribute significantly to next-generation hydrogen fuel and human-machine interfaced healthcare applications. We observe a steady improvement of over 250% in electrocatalytic activities and 400 % in outstanding sensitivity of Ir-ALD-MXene by smartly controlling the Ir-ALD cycle numbers compared to the pristine MXene. Noteworthy is the observation that the presence of Ir in the form of single atoms or clusters significantly enhances the surface catalytic and sensing activity; thus, given its limited earth abundancy, the improved catalytic-sensing performance per iridium atom, achieved with a considerably reduced quantity of the precious metals, has been comprehensively examined through computational techniques as well as next-generation aberration-corrected ultra-high-resolution electron microscopies. The current research contributes substantially to the field by establishing precise and delicate control over the arrangement of the precious metals through an emerging ALD process technique for creating new ALD precious metal-based electrocatalysts and healthcare sensors on ever-expanding MXene 2D nanomaterials.