It is an enormous challenge to construct high-energy-density materials meeting simultaneously requirements of high energy and excellent stability. In this work, the reaction of a Ag(I) ion with a nitrogen-rich ligand, 1H-tetrazole-5-acetic acid (H 2 tza), leads to a novel Ag7-cluster metal−organic framework, [Ag 7 (tza) 3 (Htza) 2 (H 2 tza)(H 2 O)] (1), with remarkable highenergy content, stability, and insensitivity. Dramatically, the heatingdehydrated process of 1 produces a new stable energetic material, [Ag 7 (tza) 3 (Htza) 2 (H 2 tza)] (1a), which features superior energy and undiminished safety performance compared to those of 1.

Host–Guest interaction is crucial to the sensitivity of heterogeneous sensors. Here, a series of isomorphic three-dimensional lanthanide metal–organic frameworks (Ln-MOFs), [Ln­(TCBA)­(H2O)2]2·DMF [H 3 TCBA = tris­(3′-carboxybiphenyl)­amine; Ln = Tb (1), Eu (2), and Gd (3); DMF = dimethylformamide] was synthesized and characterized, in which the propeller-like TCBA 3– ligands adopt special torsional link between Tb­(III) ions to form one-dimensional triangular channels. Optical experiments show that 1 exhibits bright green luminescence with an overall quantum yield of 26%, a 5D4 lifetime of 478 μs, and can act as an excellent heterogeneous fluorescent sensor to detect 2,4,6-trinitrophenol (TNP) explosive with an extremely low detection limit of 1.64 ppb. Because the confined channels within 1 exhibit matched dimensions toward TNP and feature multiple guest-response sites including rich π-conjugated groups, electron-donating N centers, and open metal nodes, strong host–guest interactions between 1 and TNP are captured and accurately determined by online microcalorimetry, which provides a distinctive thermodynamic perspective to understand the heterogeneous sensing behaviors. Additionally, the finely modulated heterometallic isomorphism [Tb0.816Eu0.184(TCBA)­(H2O)2]2·DMF emits bright white light when excited at 380 nm and could potentially be used as single-phase white light-emitting diode phosphors materials.

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Uncontrolled flow through different permeability zones in oil reservoirs remains a huge challenge during water flooding, which can significantly limit microbial-enhanced oil recovery (MEOR)) efficiency. The aim of the present work was to use polymer-based plugging to assist MEOR through laboratory simulation and field tests. An indigenous strain HB3 was evaluated under field-relevant conditions. A polymeric HPAM/Cr­(III) plugging system was optimized which was also compatible with the microorganism. Laboratory-based simulation demonstrated the selective plugging with HPAM/Cr­(III) resulting in enhanced oil recovery more significantly in the low-permeability core, increasing from 12.8% to 47.5%, compared to that in the high-permeability one, from 47.1% to 63.2%. A subsequent microbial injection enhanced the oil recovery further, also with more effective enhancement in the low-permeability core, increasing from 49.5% to 70.0% while from 67.5% to 78.0% in the high-permeability one. The field tests involving two water injection and nine oil production wells confirmed the improvement of deep profile control by polymer-based plugging, resulting in a more uniform distribution of water absorption. With subsequent microbial injection, oil recovery was significantly enhanced, achieving an ultimate recovery of 57.6% and a cumulative oil increment of 3486 t in nine wells over the 7 month field tests. It was demonstrated that the application of polymer-based plugging significantly improved MEOR efficiency, providing a new route for EOR, especially for heterogeneous reservoirs.

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