Fig. 7
SEM images of a CuPc/rGO, b NiPc/rGO, and c PbPc/rGO hybrids bridged electrode, response, and recovery curves of d CuPc/rGO, e NiPc/rGO, and f PbPc/rGO hybrid sensors in different concentrations of NH3 at room temperature and g reversibility of the response of (1) PbPc/rGO hybrid sensor to 0.75 ppm NH3 gas, (2) NiPc/rGO hybrid sensor to 50 ppm NH3 gas, and (3) CuPc/rGO hybrid sensors to 100 ppm NH3 gas