简单和可控的NiO/ZnO孔微管的制备及对痕量H_(2)S气体的增强传感

Simple and controllable preparation of NiO/ZnO porous microtube and its enhanced sensing to trace H_(2)S gas

以廉价的脱脂棉为生物质模板,通过金属硝酸盐的简单浸渍和空气煅烧可控制备出0.9 at.%NiO掺杂的六方晶相ZnO微管,探讨了煅烧温度对复合材料显微结构和气敏性能的影响,其中600℃煅烧的NiO/ZnO-600多级结构具有宽泛的孔分布和较大的比表面积(37 m^(2)·g^(-1))。气敏测试结果表明,在133℃工作温度下,NiO/ZnO-600制备的传感器对5 ppm H_(2)S气体具有较高的响应(R_(a)/R_(g)=33.6)和较低的实际检测限(LOD=1 ppb),是目前已报道的ZnO基传感器中最敏感的材料。同时,该传感器还呈现出高的选择性、好的线性关系和长期稳定性。因此,NiO/ZnO-600微管有望作为实际监测ppb级H_(2)S气体的候选敏感材料。

0.9 at.% NiO-doped hexagonal ZnO microtube was controllably synthesized by simple calcining metal nitrate solution immersed absorbent cotton bio-template in air.The influence of calcination temperature on its microstructure and gas-sensing performance has also been investigated.NiO/ZnO-600 hierarchical structure calcined at 600℃ has broad porous distribution and large specific surface area(37 m^(2)·g^(-1)).Gas sensitivity test results show that at working temperature of 133℃,NiO/ZnO-600 sensor exhibits high response(R_(a)/R_(g)=33.6)to 5 ppm H_(2)S and actual low limit of detection(LOD=1 ppb),which represents the best sensing material to H_(2)S among reported ZnO-based sensors.Meanwhile,the sensor also presents high selectivity,good linear relationship and long-term stability.Thus,NiO/ZnO-600 microtube is expected to be used as potential candidate sensing material for actual monitoring ppb-level H_(2)S.