Enhanced, stable, humidity-tolerant xylene sensing using ordered macroporous NiO/ZrO2 nanocomposites

Three-dimensional ordered macroporous NiO/ZrO2 nanocomposites are synthesized using a facile colloid crystal template method. The structure and morphology of the as-prepared NiO/ZrO2 composites are studied. These composite materials show excellent ordered porous structure with size of similar to 200 nm. The gas sensing test indicates that the composite with (Zr/Zr+Ni)similar to 0.2 gives a superior response of 25.6-100 ppm of xylene at 330 degrees C. This response is nearly ten times higher than that of pristine NiO. The sensor response is found to be fairly humidity invariant. The synergistic catalytic effect and modulation of the charge conduction mode caused by the formation of nanoscale heterojunctions are considered as the main reason for the enhanced gas sensing performance.