Effect of adding ZHS microcubes on ZnO nanorods for CO2 gas sensing applications

•ZnSn(OH)6 (ZHS) microcubes were developed on ZnO nanorods for CO2 detection.•ZHS-microcubes/ZnO-nanorods has higher gas response than pure ZnO-nanorods.•A low cost, low temperature, and short preparation time process was used to fabricate the CO2 gas sensor. Conventionally, the catalytic promotion of semiconductor metal oxide-based CO2 sensors response is simply based on chemical reaction. In most realistic applications, the sensors are operated in both sensing gas and light surrounding. Hence, we try to use a new type of catalyst, such as ZnSn(OH)6 (ZHS) has both chemical and photo catalytic functions to improve gas response more significantly. In this work, ZnO nanorods are deposited on p-type silicon substrate with and without ZHS microcubes covered on the top. The effects of adding the ZHS microcubes on CO2 sensing response have been studied in detail with experimental measurements. Experimental results show that the added ZHS microcubes promote CO2 response up to 350%, which is higher than the reported CO2 sensors with or without metal catalyst.