The Potentiodynamic Bottom-up Growth of the Tin Oxide Nanostructured Layer for Gas-Analytical Multisensor Array Chips

Abstract

We report a deposition of the tin oxide/hydroxide nanostructured layer by the potentiodynamic method from acidic nitrate solutions directly over the substrate, equipped with multiple strip electrodes which is employed as a gas-analytical multisensor array chip. The electrochemical synthesis is set to favor the growth of the tin oxide/hydroxide phase, while the appearance of metallic Sn is suppressed by cycling. The as-synthesized tin oxide/hydroxide layer is characterized by mesoporous morphology with grains, 250–300 nm diameter, which are further crystallized into fine SnO2 poly-nanocrystals following heating to 300 °C for 24 h just on the chip. The fabricated layer exhibits chemiresistive properties under exposure to organic vapors, which allows the generation of a multisensor vector signal capable of selectively distinguishing various vapors.

Quasi-2D Co3O4 nanoflakes as an efficient gas sensor versus alcohol VOCs

“…58 This might be due to a contribution of other electrochemical processes anticipated to occur at this potential. 51 At the same time, the current transient j(t) recorded in a supporting electrolyte of 0.2 M NaNO3 shows a similar behavior on par with cyclic voltammetry results which suggest the cathodic processes to occur at about -0.25 V and -1 V favoring a generation of a base (see ESI †, Figure S4). Thus, these results hint that deposition is mass-controlled at longer times; the deposited mass correlates well to the consumed charge what enables rather simple control of the amount of deposited material.…”

“…demonstrates a monotonous decay of current with time (Figure 1a). This process results in sedimentation of Co(OH)2 due to a base appearance following reduction of nitrate ions as described by [50][51][52][53] NO3 -+H2O+2e − →NO2 − +2OH − (1)…”

The Multisensor Array Based on Grown-On-Chip Zinc Oxide Nanorod Network for Selective Discrimination of Alcohol Vapors at Sub-ppm Range

“…To measure the electrical characteristics of the ZnO NR network grown over the multielectrode chip we employed the home-made experimental setup described somewhere [56]. In brief, it was composed of a PC-driven multi-channel acquisition board (NI-6259, National Instruments, Austin, TX, USA) to read out the DC resistances via a low-noise current preamplifier (SR570, Stanford Research Systems, Sunnyvale, CA, USA).…”

The Room-Temperature Chemiresistive Properties of Potassium Titanate Whiskers versus Organic Vapors

“…Each pair of electrodes of the chip array confines a segment layer ( Figure 5 a,b) whose conductance has been measured by custom-made electronics setup. This setup has been described in details earlier [ 56 ]. Briefly, it has been based on NI-6259 acquisition board whose measurement inputs have been multiplexed to the chip electrodes via low-noise current preamplifier SR570.…”