Enhanced visible light-excited ZnSnO3 for room temperature ppm-level CO2 detection

Aimed at the bottleneck problem in conventional gas sensors that the effective detection of CO2 gas can only be accomplished at concentrations above thousands of ppm and higher operating temperature, in this work, microstructured ZnSnO3 equipped with rambutan-like hexahedral features with the hollow interior was successfully synthesized through a facile one-step hydrothermal method. Visible light was utilized as an excitation source to further enhance the sensing property. The investigation elaborated that at optimum hydrothermal time of 16 h, ZnSnO3 showed a high gas response (similar to 4.65), repeatability, and long-term stability towards 400 ppm CO2 at room temperature. The response under purple light was 3.5 times higher than that under dark conditions, resulting from photoelectrons' generation. Furthermore, ZnSnO3 sensor had excellent selectivity to 50 ppm CO2. The large specific surface area and abundant oxygen vacancies of ZnSnO3 contribute to the excellent gas-sensing performance, which addresses the dilemma that it is difficult to break through the energy barrier through surface interaction to impact the band structure and carrier concentration because CO2 is a non-polar molecule formed by polar bonds. Therefore, ZnSnO3 is a promising material for the development of devices utilized in medical respiratory detection, agricultural crop growth detection and other fields. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, microstructured ZnSnO3 material with special features was successfully synthesized using a one-step hydrothermal method, and visible light was used to enhance its sensing properties for CO2 gas. The results showed that ZnSnO3 exhibited high gas response, repeatability, and long-term stability towards 400 ppm CO2 at room temperature, with a higher response under purple light excitation. Additionally, ZnSnO3 showed excellent selectivity for 50 ppm CO2, making it a promising material for devices used in medical respiratory detection, agricultural crop growth detection, and other fields.