由于甲醛是一种剧毒的挥发性有机污染物,高灵敏度和选择性的气体传感器用于低浓度甲醛监测是非常重要的。在这里,金属有机骨架(MOF)衍生的Pd/PdO@ZnO多孔纳米结构通过水热法,然后煅烧工艺合成。具体来说,以MOFs为牺牲模板,合成了具有大表面的多孔Pd/PdO@ZnO纳米材料。在煅烧过程中,使用500°C的优化温度来形成稳定的结构。更重要的是,密集的PdO@ZnO内部的材料和复合材料界面提供了大量的p-n异质结,以有效地操纵室温传感性能。由于PdO@ZnO结处的能量势垒高度对传感器电阻的影响呈指数关系,Pd/PdO@ZnO纳米材料在室温下对1-ppm甲醛表现出高灵敏度(100ppm时为38.57%),对(氨,丙酮,甲醇,和IPA)。此外,由于Pd和PdO的催化作用,气体分子的吸附和解吸加速,响应和恢复时间小到256和264秒,分别。因此,这种MOF驱动的策略可以制备具有高表面积的金属氧化物复合材料,定义明确的形态学,和令人满意的室温甲醛气体传感性能,用于室内空气质量控制。
As formaldehyde is an extremely toxic volatile organic pollutant, a highly sensitive and selective gas sensor for low-concentration formaldehyde monitoring is of great importance. Herein, metal-organic framework (MOF) derived Pd/PdO@ZnO porous nanostructures were synthesized through hydrothermal method followed by calcination processes. Specifically, porous Pd/PdO@ZnO nanomaterials with large surfaces were synthesized using MOFs as sacrificial templates. During the calcination procedure, an optimized temperature of 500°C was used to form a stable structure. More importantly, intensive PdO@ZnO inside the material and composite interface provides lots of p-n heterojunction to efficiently manipulate room temperature sensing performance. As the height of the energy barrier at the junction of PdO@ZnO exponentially influences the sensor resistance, the Pd/PdO@ZnO nanomaterials exhibit high sensitivity (38.57% for 100 ppm) at room temperature for 1-ppm formaldehyde with satisfactory selectivity towards (ammonia, acetone, methanol, and IPA). Besides, due to the catalytic effect of Pd and PdO, the adsorption and desorption of the gas molecules are accelerated, and the response and recovery time is as small as 256 and 264 s, respectively. Therefore, this MOF-driven strategy can prepare metal oxide composites with high surface area, well-defined morphology, and satisfactory room-temperature formaldehyde gas sensing performance for indoor air quality control.