Electrophoretic fabrication of ZnO/ZnO-CuO composite for ammonia gas sensing

Abstract

Nanostructured deposits of ammonia (NH 3 ) sensitive ZnO and ZnO-CuO composites were fabricated on a graphite electrode via electrophoretic deposition (EPD). Deposition was done by holding the applied voltage and deposition time constant at room temperature. Testing of sensing properties of the deposits was conducted using Wheatstone bridge circuit. SEM micrographs show a more open structure and more exposed surface area of the pure ZnO deposit compared to the ZnO-CuO deposit. The average particle size deposited at 500V for ZnO and ZnO-CuO were 241nm and 260nm respectively; whereas at 750V the average particle size is 195nm and 276nm, respectively. Deposits with greater surface area, smaller particle sizes and thicker deposits exhibit high gas sensitivity. On the other hand, addition of CuO resulted to a more compact and dense surface structure and decreased gas sensitivity. Thus, particle size and the surface structure of the deposits dictate the sensitivity of the material.

Nanoporous hybrid CuO/ZnO/carbon papers used as ultrasensitive non-enzymatic electrochemical sensors

“…13,14 The heterostructured ZnO-CuO composite material has been extensively used for non-enzymatic sensing applications due to the extension of its electron depletion layer through the formation of a p-n junction. 11,12 Therefore, a number of studies have been devoted to the synthesis of CuO-ZnO hybrid materials, [12][13][14][15][16][17][18] such as three-dimensional porous ZnO-CuO hierarchical nanocomposites fabricated by coelectrospinning 19 and ower-like CuO-ZnO heterostructured nanowire arrays on a mesh substrate obtained using a solution method. 20 Among them, 0D nanoparticles or 1D nanowires have been dominant for a long period.…”

Defect-Induced Phase Transformations in CuO Thin Films by Ag Ion Implantation and Their Gas-Sensing Applications

“…Significant work has been done on chemically doped CuO thin films to modify their physical properties. Various dopants such as Mn, Fe, Zn, Ag, Ni, Ti Li, − and In are added to CuO thin films using chemical methods. However, this method suffers from some serious drawbacks as the physical properties of the material cannot be modified in a controlled manner as can be done through the ion implantation technique.…”

Exploitation of Nano-Crystalline Cupric Cxide (CuO) Doped Zinc Oxide (ZnO) Multilayer Thick Film as a CO2 Gas Sensor

“…At 220 °C 2.7 times higher sensitivity was obtained for CuO-ZnO composite than that of pure ZnO. Ryan Dula Corpuza and Jason Rayala Albiab 2014 [6] fabricated ZnO and ZnO-CuO composites on a graphite electrode via electrophoretic deposition. Greater surface area, smaller particle sizes and thicker deposits exhibit high gas sensitivity.…”