| May 27, 2025 |
Noble metal nanoparticles boost formaldehyde detection in advanced ceramic sensor
Researchers develop a platinum-decorated ceramic sensor with high sensitivity and long-term stability for formaldehyde detection using a multi-heterojunction design.
(Nanowerk News) A team of researchers from Jiangsu University in China has developed a highly sensitive and stable sensor for detecting formaldehyde, a common indoor air pollutant known for its harmful health effects. The sensor, built using platinum nanoparticles and a ceramic composite, shows exceptional performance in identifying even trace amounts of formaldehyde in the air.
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The findings are published in Journal of Advanced Ceramics ("Pt decorated CoFe2O4/Co3O4 nanosheets derived from 2D Fe–Co MOF for enhanced HCHO detection")
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Formaldehyde is widely used in household products and building materials, and long-term exposure can lead to serious health problems. Detecting it reliably at very low concentrations is a key challenge in environmental monitoring and public health. The new sensor addresses this challenge with a smart combination of materials and design.
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At the core of the sensor is a layered ceramic structure made from cobalt and iron oxides. These materials are derived from a two-dimensional metal-organic framework, a type of porous compound with a high surface area. This structure provides plenty of active sites for gas molecules to interact with, improving the sensor’s responsiveness. To enhance its effectiveness further, the researchers added tiny platinum nanoparticles. These nanoparticles not only improve the sensor’s catalytic properties but also help form electronic junctions at the interfaces of the materials, boosting its sensitivity.
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The result is a sensor that can detect formaldehyde at levels as low as 6 parts per billion (ppb)—a concentration far below what many current sensors can detect. It also responds strongly to 100 parts per million (ppm) of formaldehyde, reaching a response level of 95.5 at an operating temperature of 280 degrees Celsius. These figures place it among the most responsive and accurate sensors developed to date.
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In laboratory tests, the sensor also demonstrated excellent stability over time, strong selectivity against other gases, and reliable performance across multiple cycles of use. This means it can consistently detect formaldehyde even in complex environments without interference from other volatile compounds.
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To understand why the sensor works so well, the team carried out a series of surface experiments and theoretical calculations. These showed that formaldehyde molecules bind strongly to the sensor’s surface, particularly where platinum is present. The platinum also facilitates the breakdown of oxygen molecules, increasing the number of reactive oxygen species on the surface. These species interact with formaldehyde, triggering detectable electrical signals.
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The researchers attribute the sensor’s superior performance to two main features: the catalytic effect of the platinum nanoparticles and the formation of multiple heterojunctions—interfaces where different materials meet, which create favorable conditions for electron movement and gas interaction.
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What makes this approach especially promising is its scalability. The sensor materials were synthesized using a straightforward solution method, which suggests they could be produced in large quantities without specialized equipment. By using a two-dimensional metal-organic framework as a template, the team was able to control the structure and composition of the final product with precision, ensuring uniform distribution of the platinum particles and consistent material quality.
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This development opens up new possibilities for low-cost, high-performance gas sensors that could be used in homes, workplaces, and public spaces to monitor air quality. The research team believes their approach could be extended to detect other harmful gases by adjusting the composition of the materials and the type of metal nanoparticles used.
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