Detection of ppb-level formaldehyde at low temperatures is a great pursuit for metal oxide semiconductor sensors. To realize this goal, metal organic framework (MOF) derived hollow hexagonal prism with surface-grown nanofibers were successfully prepared and modified using quantum dots, affording a 3D/0D heterojunction with excellent sensing performance. The CdS@c/h-InO-2 hollow hexagonal prism exhibits outstanding sensing properties (107.37 for 100 ppm), ideal selectivity, and low detection limit (160 ppb) at 160 °C. Moreover, the possible formation mechanism of the hollow hexagonal prism and endogenous phase-homojunction are proposed. Further, an insight into the synergistic enhancement of endogenous phase-homojunction and heterojunction is presented, including the gas diffusion, density functional theory (DFT) calculations, and resistance-controlled mechanism. The distinguished HCHO-sensing performance can be attributed to MOF-derived endogenous phase-homojunction, 3D/0D heterostructure, hollow morphology, and confined internal space, which ultimately synergize to strengthen the adsorption and electron transfer behavior of oxygen and HCHO molecules. Overall, this work provides new insights into the feasible strategy and theoretical viewpoint concerning high-performance HCHO sensors.

中文翻译：

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MOF衍生的CdS@c/h-In2O3空心六角棱柱与表面生长的纳米纤维用于ppb级甲醛检测：洞察内源相同质结和异质结的协同增强

低温下检测ppb级甲醛是金属氧化物半导体传感器的一大追求。为了实现这一目标，利用量子点成功制备并修饰了具有表面生长纳米纤维的金属有机框架（MOF）衍生的空心六角棱柱，提供了具有优异传感性能的3D/0D异质结。 CdS@c/h-InO-2 空心六角棱镜在 160 °C 时具有出色的传感特性（100 ppm 为 107.37）、理想的选择性和低检测限（160 ppb）。此外，还提出了空心六棱柱和内生相同质结的可能形成机制。此外，还深入探讨了内源相同质结和异质结的协同增强，包括气体扩散、密度泛函理论（DFT）计算和电阻控制机制。杰出的 HCHO 传感性能可归因于 MOF 衍生的内源相同质结、3D/0D 异质结构、中空形态和有限的内部空间，这些最终协同增强氧气和 HCHO 分子的吸附和电子转移行为。总的来说，这项工作为高性能 HCHO 传感器的可行策略和理论观点提供了新的见解。