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[Display omitted] • 2D-MOF is connected to 3D-MOF with coordination bond to form Ni-HHTP@UiO-66NH 2. • 2D-MOF@3D-MOF affords porosity, conductivity, and active interface for sensing. • Ni-HHTP@UiO-66NH 2 shows superior sensitivity and low detection limit toward H 2 S. • A plausible mechanism is proposed from the joint experimental/computational data. Research to develop ideal sensing devices for toxic gases is on the rise, and amongst various materials, metal–organic frameworks (MOFs) have opened up promising vistas as chemiresistive sensors due to their high structural and functional tunability. Here, we report the composites of dimensionally (2D and 3D) and functionally (conductive and porous) different two MOFs in the form of a well-integrated core–shell structure. The hierarchically assembled 2D-MOF@3D-MOF exhibits new interfacial properties that are responsible for synergetically enhanced sensing performances toward toxic H 2 S gas with the lowest recorded limit of detection (1.4 ppb), superior sensitivity (ΔR/R 0 = 3.37), and outstanding selectivity at room temperature in air. The sensing mechanisms are proposed by combinational studies of experiments and calculation, which indicates that multiple changes (e.g., local structural change of the shell MOF, secondary binding sites generation from the core MOF, and free radicals formation) play a critical role in achieving synergetic chemiresistive sensing. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) supported on inorganic materials have attracted much attention in numerous research fields for their high catalytic performance. However, such SACs have been limited by the low metal loading, especially on different types of inorganic supports. Herein, a general approach is presented for preparing SACs on metallic, metal oxide, and perovskite nanosheet (NS) supports to reach a high metal loading of up to 3.94 wt%, by utilizing N‐doped graphene as a sacrificial template that spatially confines the single atoms (SAs). Specifically, the target support material precursors are adsorbed onto the SAs‐stabilized sacrificial template, followed by subsequent heat treatment to transfer the SAs to the support material and to remove the graphene layer. Pt SAs on oxide support exhibits little to no aggregation throughout >10 000 min of annealing at 275 °C, demonstrating high thermal stability, as also supported by ex situ post‐anneal electron microscopy and X‐ray absorption fine structure studies. As a proof‐of‐concept, Pt SACs on SnO2 NSs exhibit high catalytic activity toward chemiresistive sensing of acetone gas (response = 95.4 at 10 ppm, 7.6‐fold enhancement compared with pristine SnO2 NSs) and unprecedented stability under highly humid conditions (27.4% response deterioration at 95% relative humidity). [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) supported on inorganic materials have attracted much attention in numerous research fields for their high catalytic performance. However, such SACs have been limited by the low metal loading, especially on different types of inorganic supports. Herein, a general approach is presented for preparing SACs on metallic, metal oxide, and perovskite nanosheet (NS) supports to reach a high metal loading of up to 3.94 wt%, by utilizing N‐doped graphene as a sacrificial template that spatially confines the single atoms (SAs). Specifically, the target support material precursors are adsorbed onto the SAs‐stabilized sacrificial template, followed by subsequent heat treatment to transfer the SAs to the support material and to remove the graphene layer. Pt SAs on oxide support exhibits little to no aggregation throughout >10 000 min of annealing at 275 °C, demonstrating high thermal stability, as also supported by ex situ post‐anneal electron microscopy and X‐ray absorption fine structure studies. As a proof‐of‐concept, Pt SACs on SnO2 NSs exhibit high catalytic activity toward chemiresistive sensing of acetone gas (response = 95.4 at 10 ppm, 7.6‐fold enhancement compared with pristine SnO2 NSs) and unprecedented stability under highly humid conditions (27.4% response deterioration at 95% relative humidity). [ABSTRACT FROM AUTHOR]

Activation of metal oxides by light is a robust yet facile approach to manipulating their surface chemistry for favorable reactions with target molecules in heterogeneous catalysis and gas sensors. However, a limited understanding of interface chemistry and the involved mechanism impedes the development of a rational design of oxide interfaces for light‐activated gas sensing. Herein, the TiOx‐assisted photosensitization of In2O3 toward NO2 sensing is investigated as a case study to elucidate the detailed mechanism of light‐activated surface chemistry at the metal/gas interface. The resultant heterogeneous oxides exhibit outstanding NO2 sensing performance under light irradiation thanks to abundant photoexcited electrons and holes that serve as adsorption and desorption sites, respectively, to accelerate both surface reactions. Furthermore, the facile transfer of electrons and holes across the TiOx‐In2O3 interface contributes to improving the reversibility of sensing kinetics. Through this study, the mechanistic understanding is established of how the surface chemistry of metal oxide surfaces can be tuned by light activation providing an effective route to the design fabrication of high‐performance gas sensors. [ABSTRACT FROM AUTHOR]

Gas Sensors In article number 2214008, Il‐Doo Kim and co‐workers investigated photosensitization of the TiO2‐In2O3 sensing layer to enhance the NO2 detection capabilities of oxides. The heterogeneous interface engineered between two dissimilar oxides improved the accumulation of photogenerated charge carriers, which accelerated the adsorption and desorption of NO2 molecules. The study elaborates on the light‐mediated modulation of the oxide surface chemistry and establishes a rational design of cost‐effective light‐activated gas sensors. [ABSTRACT FROM AUTHOR]

Gas sensors, heterojunctions, indium oxides, interfacial engineering, photocatalysts, semiconducting oxides Keywords: gas sensors; heterojunctions; indium oxides; interfacial engineering; photocatalysts; semiconducting oxides EN gas sensors heterojunctions indium oxides interfacial engineering photocatalysts semiconducting oxides 1 1 1 04/27/23 20230425 NES 230425 B Gas Sensors b In article number 2214008, Il-Doo Kim and co-workers investigated photosensitization of the TiO SB 2 sb -In SB 2 sb O SB 3 sb sensing layer to enhance the NO SB 2 sb detection capabilities of oxides. Imparting Metal Oxides with High Sensitivity Toward Light-Activated NO2 Detection Via Tailored Interfacial Chemistry (Adv. Funct. [Extracted from the article]