Investigation of the performance of cobalt-graphene composites for VOC detection in the environment

Abstract

Gas sensors based on metal oxide semiconductors have gained significant attention due to their cost-effectiveness, stability, and ease of production. This study investigates the performance of Co3O4/reduced graphene oxide (RGO) nanomaterials (C/R) for volatile organic compound (VOC) detection. The novel composite materials were synthesized via a one-step hydrothermal method with varying composite ratios. These materials were employed to fabricate thermal gas-sensitive elements, and their gas-sensing characteristics were extensively examined using a testing system. The study explores the influence of composite amount, working temperature, and gas concentration on the sensor's response. Importantly, the selectivity of Co3O4 and C/R materials towards key VOCs, including acetone, methanol, ethanol, xylene, toluene, and formaldehyde, was evaluated. The results underscore the exceptional gas-sensing potential of the C/R composite, particularly the variant with an optimized ratio of components (C/R-2). This composite exhibited remarkable sensitivity to 100 ppm toluene gas at an operating temperature of 260 ℃. The enhanced performance is attributed to the synergistic effects between Co3O4 and RGO, leading to improved selectivity and lower detection limits. The investigation revealed that the developed sensor outperforms pure Co3O4 in terms of sensitivity, response time, and stability. The findings not only contribute to the fundamental understanding of composite materials for gas sensing applications but also hold significant promise for addressing environmental VOC detection challenges.