Exploring MOF-Derived CuO/rGO Heterostructures for Highly Efficient Room Temperature CO₂ Sensors

In response to the urgent need for advanced climate change mitigation tools, this study introduces an innovative CO₂ gas sensor based on p-p-type heterostructures designed for effective operation at room temperature. This sensor represents a significant step forward, utilizing the synergistic effects of p-p heterojunctions to enhance the effective interfacial area, thereby improving sensitivity. The incorporation of CuO nanoparticles and rGO sheets also optimizes gas transport channels, enhancing the sensor's performance. Our CuO/rGO heterostructures, with 5 wt % rGO, have shown a notable maximum response of 39.6-500 ppm of CO₂ at 25 °C, and a low detection limit of 2 ppm, indicating their potential as high-performance, room-temperature CO₂ sensors. The prepared sensor demonstrates long-term stability, maintaining 98% of its initial performance over a 30-day period when tested at 1-day intervals. Additionally, the sensor remains stable under conditions of over 40% relative humidity. Furthermore, a first-principles study provides insights into the interaction mechanisms with CO₂ molecules, enhancing our understanding of the sensor's operation. This research contributes to the development of CO₂ monitoring solutions, offering a practical and cost-effective approach to environmental monitoring in the context of global climate change efforts.