ZnO Nanorod Gas Sensors with Orthogonal CuO Nanoplates for Multi-Gas Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ZnO/CuO composite materials exhibit limited gas sensitivity and selectivity, particularly at room temperature or controlled temperatures below 200°C.
Innovation Solution
A metal oxide heterostructure is created by depositing ZnO nanorods with transversal oxidized copper nanoplates, such as CuO, Cu2(OH)3Cl, and Cu(OH)2, to enhance gas sensitivity and selectivity, achieved through a method involving pH manipulation and annealing to convert Cu2(OH)3Cl nanoplates into CuO nanoplates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ZnO/CuO composite materials with CuO particles are used, then gas sensitivity to H2S is improved, but gas sensitivity at room temperature or below 200°C remains limited
Solution Approach 1:
The patent uses a composite heterostructure of ZnO nanorods and CuO nanoplates, combining two different metal oxides with complementary properties. The ZnO provides a robust scaffold while CuO nanoplates contribute to enhanced gas sensitivity at lower temperatures, resolving the contradiction between achieving high sensitivity and maintaining low operating temperature.
Solution Approach 2:
The patent transitions from zero-dimensional CuO particles to two-dimensional CuO nanoplates. This dimensional change increases the specific surface area and exposes more active sites for gas adsorption, thereby enhancing sensitivity at lower temperatures without requiring higher operating conditions.
2Measurement precision
If CuO particles are uniformly distributed on ZnO nanorods, then selectivity to H2S is improved, but chemiresistive sensitivity and selectivity to multiple gases remains limited
Solution Approach 1:
The CuO nanoplates on ZnO nanorods create a universal sensing platform that can detect multiple gases (O2, H2, CO, ethanol, NO2) with high selectivity. The heterostructure enables simultaneous optimization for specific gas detection while maintaining broad multi-gas sensing capability, resolving the contradiction between specialized and versatile sensing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting structure increases the chemiresistive sensitivity and selectivity to gases like O2, H2, CO, and NO2 by maximizing the contact surface with gases, demonstrating improved performance in gas sensing applications.
Implementation Method 1
annealing to convert Cu2(OH)3Cl nanoplates into CuO nanoplates
Implementation Method 2
convert Cu2(OH)3Cl nanoplates into CuO nanoplates
Implementation Method 3
gas sensing layer showing an electrical resistivity that varies when contacted by the gas
Data Source
AI summary
a metal oxide material comprising ZnO nanorods and oxidized copper nanoplates extending transversally to the ZnO nanorod; a method for synthetizing the metal oxide material; and a gas sensor comprising a substrate; at least two electrodes deposited on the substrate; a gas sensing layer comprising ZnO nanorods deposited on the at least two electrodes and on the substrate between said at least two electrodes, said gas sensing layer showing an electrical resistivity that varies when contacted by the gas; wherein the ZnO nanorods are provided with transversal nanoplates of CuO so as to confer sensitivity of the gas sensing layer to the gas being at least one of O2, H2, CO, ethanol and NO2.