Laser-Induced Hydrothermal Growth of Iron Oxide Nanoparticles on Diverse Substrates for Flexible Micro-Supercapacitors

Abstract

State-of-the-art microdevice fabrication requires patterned growth of functional nanomaterials on the desired position of the desired substrate. However, it is challenging, particularly in conventional hydrothermal synthesis, due to difficulties generating a local high-temperature field at the desired place. We introduce a laser-induced hydrothermal growth (LIHG) process for the rapid and selective synthesis of iron oxide nanoparticles (NPs). The substrates absorb the laser energy to generate a local high-temperature field necessary for the growth of iron oxide NPs. On various substrates, a dome-like structure comprising many iron oxide NPs is selectively synthesized within a localized temperature field. The LIHG process has several advantages for iron oxide NP growth, including rapidity, seedless growth, substrate compatibility, position selectivity, and patterning availability. Using its advantages, the LIHG process is used to fabricate flexible micro-supercapacitors based on laser-carbonized colorless polyimide films with iron oxide NPs.

Microsupercapacitive Stone Module for Natural Energy Storage

“…The details are presented in Figure e and the Supporting Information Movie S1. Figure S16 shows quantitative data for evaluating mechanical stability of the MSC stone module, which were obtained by measuring the areal capacitance performance of the energy device according to the number of drops from a height of 0.15 m. Despite hundreds of repetitive dropping tests, the variation of areal capacitance of the device was within the range of measurement error (0.3%), verifying its excellent mechanical reliability and stability. ,, …”

“…Figure S16 shows quantitative data for evaluating mechanical stability of the MSC stone module, which were obtained by measuring the areal capacitance performance of the energy device according to the number of drops from a height of 0.15 m. Despite hundreds of repetitive dropping tests, the variation of areal capacitance of the device was within the range of measurement error (0.3%), verifying its excellent mechanical reliability and stability. 60,61,62 Once the lifetime of an energy device ends, material waste is inevitable, which needs to be carefully considered to realize ecofriendly power supply systems based on ESSs. Figure 6a schematically illustrates the recycling process proposed to minimize the material waste and achieve a green energy storage platform.…”

Laser Processing of Flexible In-Plane Micro-supercapacitors: Progresses in Advanced Manufacturing of Nanostructured Electrodes

“…Facing these issues that need to be addressed, many attempts to directly grow NWs in specific places that combine growth, harvesting and placement processing have emerged. Among the proposed techniques, laser-induced hydrothermal growth (LIHG) technique shows great potential for flexible in-plane MSCs because of the growth of TMO NWs/NPs by photochemical or photo-thermochemical reaction only at specific places without multiple steps. ,− Additionally, the technique has characteristics of low cost, low temperature, ambient pressure, and environment friendliness. In addition, the length of the formed TMO NWs is longer than that formed by traditional growth in a single point without precursor solution refreshment.…”

Advances in Engineered Metal Oxide Thin Films by Low-Cost, Solution-Based Techniques for Green Hydrogen Production

“…From a technological and commercial viewpoint, these aspects that are associated with low energy consumption superimpose over the similar solvothermal synthesis, due to the absence of a non-aqueous solvent or a surfactant to assist the chemical reactions. Thus, hydrothermal synthesis represents an environmentally friendly option for metal oxide synthesis, both in powder and film form [82][83][84].…”