Formaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In2O3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In2O3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In2O3 exhibits a sluggish response (Ra/Rg = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In2O3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In2O3 nanograin, greatly enhancing the selectivity and sensitivity.

中文翻译：

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Ag纳米颗粒敏化了In2O3纳米颗粒，用于室温下的超灵敏HCHO检测。

甲醛（HCHO）是室内空气污染物的主要来源。因此，HCHO传感器对于日常生活中的及时检测至关重要。然而，现有的传感器不能满足严格的性能目标，而由于在室温下，例如在极低的甲醛浓度（尤其是低于0.08ppm）下的感测检测而导致的失活是尚未广泛解决的问题。在这里，我们介绍了通过低制造成本的水热策略敏化分散的In2O3纳米颗粒的Ag纳米颗粒（Ag NPs），其中Ag NPs降低了HCHO运入和运出In2O3纳米颗粒的表观活化能，同时在实现了低工作温度。原始的In2O3响应缓慢（Ra / Rg = 4.14至10 ppm），并且无法完全回收到HCHO气体中。