CuO meso–macroporous microspheres: calcination-time-dependent gas-sensing performance

Meso–macroporous copper (II) oxide (CuO) microspheres composed of thin nanosheets were prepared by a simple one-step solvothermal method with postcalcination and characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM and the Brunauer–Emmett–Teller method. We can effectively control pore structure by means of only regulating calcination time, and at the same time keep the other structure parameters (such as microspheres morphology, crystalline size, thickness of nanoshees) unchanged. It was found that the gas-sensing performance is positively correlated with pore structure parameters (specific surface area and pore volume) – that is, the larger the specific surface area and the pore volume, the better the gas-sensing performance. In addition, the order of the gas-sensing performance is not correlated with the other pore structure parameters (pore size and pore size distribution). In this work, the optimum calcination time was 60 min, at which the largest specific surface area and pore volume, and thereby the best gas-sensing performance, were achieved.