Submicrometer‐Sized Vaterite Tubes Formed Through Nanobubble‐Templated Crystal Growth

Abstract

(0.1±0.5 A/g) using a VMP (Biologic, France). Impedance spectroscopy measurements, in the frequency range from 100 kHz to 1 mHz, were also performed at open circuit voltage with a ±10 mV voltage amplitude using an Autolab-Ecochemie FRA2 BV.

Bacterially mediated mineralization of vaterite

“…In particular, abiotic vaterite typically forms micron-sized spherulites (solid or hollow) made up of fibrous-radiate crystals (Cölfen and Antonietti, 1998;Vecht and Ireland, 2000). Furthermore, vaterite with worm-like morphologies very similar to that of the putative bacterial carbonates in ALH84001 meteorite have been produced abiotically in the absence of organics (Fan and Wang, 2005). The recognition of bacterial biosignatures based on purely morphological considerations is therefore very difficult.…”

Construction of coral-like complex: Controlled growth of vaterite submicron hairs on flat films and hemispheres

“…Previously, vaterite nanotubes were produced through the nanobubble templates by a water-electrolysis-mineralization of calcium carbonate [21], and it was reported that vaterite nanowires could be prepared by the cooperative interaction of self-assembled monolayers (SAMs) with -COOH group and PAA at 45 1C. Balz et al [22] suggested that the complex of SAMs with PAA played as a template during the formation of nanowires.…”

Manipulating surface nanobubbles

“…Second, more fundamentally, nanobubbles should not exist: According to the experimental data these bubbles have a radius of curvature R smaller than 1µm, and therefore they should dissolve on timescales far below a second [22,23], due to a large Laplace pressure inside of the bubbles, which in a bubble, with radius of e.g. 200 nm amounts to approximately 5 atm.…”

“…Most studies have hitherto focused on mini-or micrometer sized bubbles, which are formed at and subsequently detach from the electrodes; see [20][21][22][23][24][25] and references therein. The formation of hydrogen microbubbles on a negative electrode has been witnessed by phase-contrast (a) 300 µm Figure 5.1: Phase-contrast microradiograph revealing the generation of micrometer sized hydrogen bubbles on an electrode that acts as cathode.…”

“…The interest in electrochemically generated nanobubbles is more recent. It has been hypothesized that the existence of nanobubbles at electrode surfaces favors the formation of submicrometersized vaterite tubes in the electrolysis-induced mineralization [22]. Zhang et al [9] confirmed that electrochemical generation of hydrogen induces the formation of nanobubbles on the electrode surface in sulfuric acid solution.…”