Platinum Nanoparticle Decorated SiO₂ Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

Abstract

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP–SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP–SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2. The concomitance of facile fabrication, economic and scalable processing, and high performanceincluding a reduction in H2O2 decomposition activation energy of 40–50% over conventional material catalystspaves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems.

Laser-induced graphene electrodes for electrochemical ion sensing, pesticide monitoring, and water splitting

“…Pt was electrolessly deposited onto the LIG by immersing the sample into a chloroplatinic acid solution following the protocol that was previously developed in our group [55][56][57]. The method can deposit platinum onto various surfaces, such as carbon-based materials (carbon nanotube, carbonized wood, graphene) and others like cellulose and SiO 2 wools with surface functionalization [55,56,58]. After 20 h, a layer of Pt deposits onto the surface of LIG as shown in ESM Fig.…”

Neuro‐Nano Interfaces: Utilizing Nano‐Coatings and Nanoparticles to Enable Next‐Generation Electrophysiological Recording, Neural Stimulation, and Biochemical Modulation

“…Similar to silver, platinum has been briefly explored for use in neural interfaces, [88][89][90] but nano-platinum must be carefully employed due to its potential as a highly reactive catalyst of simple compounds that may be found in physiological media. [91][92] Shah et al used nano-cluster platinum films to enhance implantable electrode performance. [93] Flexible MEAs were coated with nano-platinum to create electrodes with a decreased impedance that was more stable over a larger range of frequencies and reduced degradation when compared to non-coated MEAs.…”

“…The demonstration of MEA fabrication on hydrogel substrates is an important step toward neural implants which match the mechanical properties of the brain and other excitable tissue. Similar to silver, platinum has been briefly explored for use in neural interfaces, but nano‐platinum must be carefully employed due to its potential as a highly reactive catalyst of simple compounds that may be found in physiological media . Shah et al used nano‐cluster platinum films to enhance implantable electrode performance .…”

Improving sensitivity of electrochemical sensors with convective transport in free-standing, carbon nanotube structures

“…Platinum nanowires (PNs) were deposited onto the CNT sensors in a static, electroless environment using a chemical reduction of chloroplatinic acid hexahydrate (37.5% Pt, Sigma-Aldrich 206083) similar to our previous protocols [34,39,40]. The concentration used in each deposition was dependent on the mass of the CNT sensor, with a target of 30% Pt to carbon weight in solution (2.9 ± 0.4 mM chloroplatinic acid).…”