Reduced graphene oxide (rGO) has attracted enormous interest as a promising candidate material for gas detection due to its large specific surface areas. In our work, rGO films were fabricated on a large scale using dip-coating and spin-coating methods for the detection of nitrogen dioxide (NO₂) gas at room temperature. The influence of different test environments on the sensing performance, including the test atmosphere, gas flow and gas pressure was evaluated. The response time of the dip-coating method was 573 s with a long recovery period of 639 s and for the spin-coating method, the response time and recovery time was 386 s and 577 s, respectively. In addition, the spin-coated sensor exhibited high selectivity to NO₂, with the response increasing by more than 20% (for 15 ppm NO₂) as compared with that for HCHO, NH₃, and CH₄. Our results indicated that the spin coating method was more suitable for rGO-based gas sensors with higher performance.

This review highlights advances in nanostructured transition metal catalysts supported on nickel foam, spanning rational design to high-performance alkaline oxygen evolution.