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Photocatalytic nitrogen fixation is a potentially viable approach to meet the enormous demand for N-based chemicals such as ammonia and nitrates. However, light-driven nitrogen fixation is a complex reaction from both kinetic and thermodynamic perspectives. Also, there has not been much emphasis on the simultaneous production of ammonia and nitrate. In addition, there is much debate regarding the correctness of the quantification of photogenerated NH3. In this work, we reported the overall nitrogen fixation over the surface of defect-rich Mo-doped Sb2WO6 nanobelts without the use of an electron or hole scavenger. One of the samples (SWMO0.1) with an optimum amount of Mo was found to possess the best catalytic activity for ammonia generation with a yield rate of 24 μmol g–1 h–1 as compared to the pristine Sb2WO6 sample (4 μmol g–1 h–1). Also, the solar to ammonia (STA) efficiency was found to be 0.035%. The photogenerated ammonia concentration was quantified using indophenol, Nessler's reagent, and ion chromatography, and a detailed comparison was made to examine the reliability of these methods. The ammonia concentration measured using ion chromatography was much lower than that measured using the other two calorimetric methods (indophenol and Nessler's reagent), indicating uncertainties in the accurate determination of ammonia concentration. Further, nitrate and nitrite species formed were also quantified. Thus, this work provided insights into the uncertainties in the quantification of photocatalytically produced ammonia using Mo-doped Sb2WO6 nanobelts as catalysts. [ABSTRACT FROM AUTHOR]

Noninvasive control over the reversible generation of singlet oxygen (1O2) has found the enormous practical implications in the field of biomedical science. However, metal‐free pure organic emitters, connected with a photoswitch, capable of generating "on‐demand" 1O2via triplet harvesting remain exceedingly rare; therefore, the utilization of these organic materials for the reversible control of singlet oxygen production remains at its infancy. Herein, an ambient triplet mediated emission in quinoline‐dithienylethene (DTE)‐core‐substituted naphthalene diimide (cNDI) derivative is unveiled via delayed fluorescence. The quinoline‐DTE‐cNDI triad displayed enhanced photoswitching efficiency via double FRET mechanism. It was found to have direct utilization in controlled photosensitized organic transformations via efficient generation of singlet oxygen (yield ΦΔ~0.55 in DCM and 0.73 in methanol). The designed molecule exhibits a long‐lived emission (τ∼1.1 μs) and very small singlet‐triplet splitting (ΔEST) of 0.13 eV empowering it to display delayed fluorescence. Comprehensive steady state and time‐resolved emission spectroscopy (TRES) analyses along with DFT calculations offer detailed understandings into the excited‐state manifolds of organic compound and energy transfer (ET) pathways involved in 1O2 generation. [ABSTRACT FROM AUTHOR]

The rapid pace of industrialization has led to a multitude of detrimental environmental consequences, including water pollution and global warming. Consequently, there is an urgent need to devise appropriate materials to address these challenges. Ionic porous organic polymers (iPOPs) have emerged as promising materials for oxoanion sequestration and non‐redox CO2 fixation. Notably, iPOPs offer hydrothermal stability, structural tunability, a charged framework, and readily available nucleophilic counteranions. This review explores the significance of pores and charged functionalities alongside design strategies outlined in existing literature, mainly focusing on the incorporation of pyridinium and imidazolium units into nitrogen‐rich iPOPs for oxoanion sequestration and non‐redox CO2 fixation. The present review also addresses the current challenges and future prospects, delineating the design and development of innovative iPOPs for water treatment and heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

A porous organic polymer (POP) has been developed for dual-ion storage in all organic symmetric rechargeable batteries. The triphenylamine-pyrene-based POP could host sodium and hexafluorophosphate ions acting as the anode and the cathode, respectively, through the adsorption-intercalation and insertion mechanism. The current study highlights the concept of widening the potential window of a dual ion battery by judicious selection of the constituent moieties. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are a fast‐developing family of porous organic materials that have received substantial research interest during the last two decades. Dynamic covalent chemistry (DCC) is the cornerstone of COF fabrication. DCC is a process that entails reversible bond breaking‐reforming under equilibrium to attain the thermodynamically most stable structure. Due to the reversible nature of the covalent linkages, the building blocks of pre‐synthesized COF or pre‐assembled chemical entities, like network polymers and supramolecular hosts, can be replaced postsynthetically under appropriate reaction conditions. The technique is known as postsynthetic linker exchange (PLE). PLE provides an easy way to introduce functional building blocks into the COF backbone and control its chemical and physical properties. In this article, we have highlighted the recent advancements (from 2017 to 2023) in the postsynthetic linker exchange strategy for constructing highly crystalline and porous COFs that are often unattainable via de novo fabrication. The mechanistic insights of the linker exchange process for transforming various parent entities, such as COFs, amorphous covalent organic networks, linear polymers, and molecular cages to daughter COFs, have been deliberated with fascinating examples. We have also outlined some future avenues for applying the PLE process for the large‐scale fabrication of highly crystalline COFs for real‐time applications. [ABSTRACT FROM AUTHOR]

Dynamic covalent chemistry (DCC) opens up a fascinating route for the construction of well‐organized supramolecular architectures, starting from organic molecular cages to crystalline macromolecular covalent organic frameworks (COFs). Herein, for the first time, we have manifested a facile room‐temperature DCC‐directed transformation of discrete organic imine cage‐to‐COF film at the liquid–liquid interface. The unfolding of the cage leading to the generation of imine intermediates, followed by their interface‐assisted preorganization and subsequent growth of the COF film, are elucidated through detailed spectroscopic and microscopic investigations. The interfacial cage‐to‐COF transformation provides a facile route for the faster fabrication of free‐standing COF films with high porosity and crystallinity, demonstrating excellent performance towards molecular sieving and high solvent permeance. Thus, the current study opens up a new route for structural interconversion between two crystalline entities with diverse dimensionality employing DCC at the confined interface. [ABSTRACT FROM AUTHOR]