Metal oxide-based chemiresistive gas sensors are expected to play a significant role in assessing human health and evaluating food spoilage. However, the high operating temperature, insufficient limit of detection (LOD), and long response/recovery time restrict their broad application. Herein, 3D Bi₂MoO₆/2D Eg-C₃N₄ heterocomposites are developed for advanced NH₃ gas sensors with RT operational mode. Utilizing the synergetic engineering of micro-nanostructure, surface oxygen vacancies, and well-defined Type II n–n heterojunctions, BMOCN3 demonstrated superior NH₃ sensing properties at 23 °C, including the high response (S = 13.6 at 10 ppm), fast response/recovery speed (8/30 s), excellent selectivity, and low LOD (166 ppb). Based on the experimental, DFT, and MD studies, the improved sensing performance can be ascribed to accelerated charge transfer, superior redox capacity, and improved adsorption/desorption kinetics. Moreover, the practical application in rapid exhaled NH₃ biomarker detection of the as-fabricated gas sensor was preliminarily verified. This work highlights that the novel synergetic engineering can effectively modulate the electronic structure and charge transfer, offering a rational solution for room temperature chemiresistive gas sensors.

中文翻译：

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氧空位介导的钼酸铋/石墨氮化碳 II 型异质结化学电阻器，用于在室温下进行高效的 NH3 检测


基于金属氧化物的化学电阻气体传感器有望在评估人类健康和评估食品变质方面发挥重要作用。然而，高工作温度、检测限 （LOD） 不足和较长的响应/恢复时间限制了它们的广泛应用。在此，3D Bi₂MoO₆/2D Eg-C₃N₄ 异质复合材料是为具有 RT 操作模式的先进 NH₃ 气体传感器开发的。利用微纳结构、表面氧空位和明确的 II 型 n-n 异质结的协同工程，BMOCN3 在 23 °C 下表现出卓越的 NH₃ 传感特性，包括高响应（10 ppm 时 S = 13.6）、快速响应/恢复速度 （8/30 s）、出色的选择性和低 LOD （166 ppb）。根据实验、DFT 和 MD 研究，传感性能的改善可归因于加速的电荷转移、卓越的氧化还原能力和改进的吸附/解吸动力学。此外，初步验证了所制备气体传感器在快速呼出气 NH₃ 生物标志物检测中的实际应用。这项工作强调，新颖的协同工程可以有效地调节电子结构和电荷转移，为室温化学电阻气体传感器提供了合理的解决方案。