研究目的
To develop a highly selective and sensitive xylene gas sensor using NiO/NiCr2O4 p-p nanoparticles for indoor air monitoring.
研究成果
The NiO/NiCr2O4 (Cr/Ni=25 at%) gas sensor demonstrated superior xylene sensing properties, including high sensitivity (66.2 response to 100 ppm xylene), excellent selectivity (low cross-responses to interfering gases), low detection limit (1.2 response to 50 ppb xylene), and good long-term stability. The enhanced performance is attributed to small grain size, large surface area, mesoporous structure, formation of p-p heterojunctions, and synergistic catalytic effects. This sensor shows potential for practical indoor air quality monitoring of xylene.
研究不足
The response and recovery times were relatively long (1217 s and 591 s for 100 ppm xylene), which could be optimized for faster detection. Humidity interference affected performance, with resistance increasing and response decreasing at higher RH levels. The study was conducted under laboratory conditions, and real-world applications might face additional environmental variables.
1：Experimental Design and Method Selection:
The study involved synthesizing NiO/NiCr2O4 nanocomposites via a hydrothermal route to create sensing materials for chemiresistive gas sensors. The rationale was to leverage the synergistic effects between NiO and NiCr2O4 for enhanced gas sensing performance.
2：Sample Selection and Data Sources:
Samples with different Cr/Ni ratios (10, 25, 50, 75, 100 at%) and pure NiCr2O4 (Cr/Ni=200 at%) were prepared using analytical grade reagents like CrCl3?6H2O, NiCl2?6H2O, hexamethylenetetramine (HMT), and ethanolamine. Data on gas responses were collected using a static test system.
3：List of Experimental Equipment and Materials:
Equipment included FESEM (JSM-7500F JEOL), TEM (JEM-2200FS JEOL), XRD (Rigaku D/Max-2550), XPS (Specs XR50 with Mg-Kα X-ray), BET (Micromeritics Gemini VII apparatus), and a gas sensor setup with ceramic tubes, gold electrodes, Pt wires, Ni-Cr alloy coil heater, and hexagon base. Materials involved deionized water, ethanol, and various chemical reagents.
4：Experimental Procedures and Operational Workflow:
The synthesis involved hydrothermal reaction at 180°C for 8 h, centrifugation, drying at 80°C, and heat treatment at 500°C for 3 h. Sensors were fabricated by coating slurries on ceramic tubes, sintering at 500°C, and aging. Gas sensing tests were conducted at 20°C and 10% RH, measuring resistances in target gases and air.
5：Data Analysis Methods:
Gas response was defined as Rg/Ra for p-type sensors. Response and recovery times were measured as times to reach 90% saturation. Data were analyzed using statistical methods and software tools inherent to the characterization equipment.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
