Laser treatment realizes highly conductive PEDOT:PSS transparent films (932 S cm−1), enabling selective doping and facile, fast patterning.

We investigated the static charge generation by contact electrification between Au and polydimethylsiloxane (PDMS) and the redox reaction by the static charge in the aqueous phase, to reveal the mechanism of contact electrification and redox reaction which may be applied to mechanical-to-chemical energy harvesting. First, the static charge distribution on the equipotential Au was probed through Kelvin probe force microscopy (KPFM) in air after the contact with patterned PDMS. Positive charges are localized on the contact areas indicating the ion migration while the polarity becomes negative after water contact. Second, the redox reaction by the charged Au was electrochemically monitored using open circuit potential (OCP), stripping voltammetry, and copper underpotential deposition (UPD). All electrochemical experiments consistently resulted in the reduction of the reactant by the charged Au within the highly dielectric water media. We concluded that the reduction is not driven by the discharge of static charge on Au but by reducing radicals.

Hybrid gas/liquid-fed electrochemical flow reactors may become attractive alternatives for chemical synthesis once it is understood how catalytic product selectivity may be optimized through the control of gas phase reactants. Using a constant pH basic electrolyte to suppress the hydrogen evolution reaction, we explore how protonation by water vapor added to the flowing CO 2 supply affects the CO 2 reduction reaction. Although H 2 remains the dominant product, supplying dry CO 2 gas selectively produces more C 2 products than C 1 . However, adding protons through water vapor changes selectivity toward C 1 products, increasing the overall faradaic efficiency of hydrocarbon production while reducing H 2 production.

This study investigated which factors decisively influence colloidal nanoparticle (NP) assembly on a self-assembled monolayer (SAM)-patterned substrate. Zirconia (ZrO2) NP assembly on a poly(dimethylsiloxane) (PDMS)-stamped SAM-patterned Au substrate was carried out while the size and surface charge state of the NPs and the substrate wettability were altered. ZrO2 particles with diameters of 350 nm, 560 nm, and 1100 nm were employed to examine the effect of NP size on the assembly. Bare ZrO2 NPs with a negatively charged surface and ZrO2 NPs with a positively charged surface through 3-aminopropyltriethoxysilane encapsulation were prepared for the NP assembly. Moreover, the substrate wettability effect on the NP assembly was evaluated by comparing the assembly on substrates with the PDMS-patterned SAMs of thiols with polar and non-polar functional groups. From the characterization of the number of NPs in a pattern and the effective area of assembled NPs (Aeff), positively charged ZrO2 NP assembly on negatively charged patterns showed the highest number density of particles in a pattern compared with the other combinations in both 350-nm and 560-nm ZrO2 NPs. This observation can be attributed to negatively charged 16-mercaptohexadecanoic acid SAMs having greater polarity (more polar groups) than positively charged 11-amino-1-undecanethiol SAMs within the condition of the colloidal ZrO2 NP assembly.