Anisotropic Metal Deposition on TiO₂ Particles by Electric‐Field‐Induced Charge Separation

Abstract

Deposition of metals on TiO semiconductor particles (M-TiO ) results in hybrid Janus objects combining the properties of both materials. One of the techniques proposed to generate Janus particles is bipolar electrochemistry (BPE). The concept can be applied in a straightforward way for the site-selective modification of conducting particles, but is much less obvious to use for semiconductors. Herein we report the bulk synthesis of anisotropic M-TiO particles based on the synergy of BPE and photochemistry, allowing the intrinsic limitations, when they are used separately, to be overcome. When applying electric fields during irradiation, electrons and holes can be efficiently separated, thus breaking the symmetry of particles by modifying them selectively and in a wireless way on one side with either gold or platinum. Such hybrid materials are an important first step towards high-performance designer catalyst particles, for example for photosplitting of water.

Wireless Dual Stimuli Actuation of Dye Sensitized Conducting Polymer Hybrids

“…The impact of light generates an electron-hole pair in the TiO 2 -MB-PPy matrix, and these charge carriers are separated under the influence of the electric field and are driven to the respective extremities where they can induce redox reactions. [13] Initially, the synthesized PPy film is in a fully oxidized state and loaded with dodecylbenzene sulfonate (DBS) and iodide ions as a result of the electrosynthesis and the treatment with KI/I 2 solution. Consequently, the reduction of the polymer strip at the δ − extremity leads to a preferential release of iodide ions, Scheme 1.…”

“…The impact of light generates an electron‐hole pair in the TiO 2 ‐MB‐PPy matrix, and these charge carriers are separated under the influence of the electric field and are driven to the respective extremities where they can induce redox reactions. [ 13 ]…”

Toward High‐Performance Triboelectric Nanogenerators by Engineering Interfaces at the Nanoscale: Looking into the Future Research Roadmap

“…[ 90–98 ] The effective/active contact surface area can be increased significantly by surface roughening. [ 1,99–101 ] Extensive investigations on triboelectric energy harvesters have focused on morphological adjustments to the surface at both the micro‐ and nanoscales, such as nanowires, nanorods, and nanoparticles to attain an improved surface area for effective charge production and higher TENG performance. This result is due to the increased contact area when more force is applied.…”

Designing tubular conducting polymer actuators for wireless electropumping

“…In this case, two coupled electrochemical reactions occur simultaneously at the two extremities of the polymer object. This typical feature of bipolar electrochemistry has been previously also explored for functional material synthesis, [36][37][38][39][40] surface patterning, 41,42 locomotion, 43,44 sensing 33,45,46 and light emission. [47][48][49] In the present contribution, we investigate for the rst time the possibility of using this versatile concept for the development of wireless tubular electrochemical actuators based on an electric eld responsive conducting polymer i.e.…”