Controlling hierarchical organization across multiple length scales is a central challenge in materials science. Microspherical architectures offer powerful platforms for addressing this challenge because their confined geometry enables the integration of nanoscale interfaces, internal porosity, and structural hierarchy within a single functional unit. These features have driven extensive exploration of microspheres for applications in biomedicine, catalysis, photonics, and energy systems. However, the mechanistic connections between microsphere formation pathways and emergent functionality remain fragmented, limiting predictive materials design. Here, we present a unified perspective on morphology-controlled microspheres by integrating thermodynamic principles, kinetic processes, and hierarchical materials design. We examine key formation mechanisms, including nucleation, growth dynamics, phase separation, Ostwald ripening, and interfacial energy regulation, and analyze how major fabrication strategies such as sol–gel processing, hydrothermal synthesis, spray assembly, emulsification, and co-precipitation govern nanoscale organization and structural evolution. By linking formation mechanisms with functional outcomes, this Review establishes general design principles and highlights emerging opportunities for predictive nanoarchitectonic engineering of microsphere-based functional materials.
Since its first report in 1961, the Gewald reaction has evolved as a powerful tool for the construction of the 2-aminothiophene framework. Toward the synthesis of 2-aminothiophenes, in the past 4–5 decades, a plethora of publications have appeared in the scientific literature, but Gewald’s strategy remains dominant among other methods due to its simplicity and the development of its different versions. This review showcases recent advances in Gewald methodologies for the fabrication of thiophene derivatives over the past one and a half decades, since the last update was reviewed. The present comprehensive manuscript, besides covering the traditional Gewald procedures, also exposes modern developments—for example, microwave and ultrasound-assisted synthesis, and the use of ionic liquids (ILs), deep eutectic solvents (DESs), and phase-transfer catalysts (PTCs). Herein, we have not only illustrated the details of the advancements in this still-emerging field, but have also illustrated its superiority, simplicity, and advantages in comparison with the existing methods.
1,2-Dicarbonyl compounds or α-dicarbonyls are important synthetic intermediates widely used in organic synthesis, medicinal chemistry, and materials science due to their unique reactivity and versatility. In recent years, significant progress has been made in developing efficient methods for synthesizing them from diverse substrates, including heterocycles, alkenes, alkynes, ketones, and aromatic systems. This review provides an overview of recent advances reported between 2014 and 2026, covering transition-metal-catalyzed, metal-free, photocatalytic, electrochemical, and catalyst-free strategies. Emphasis is placed on reaction mechanisms, substrate scope, functional-group tolerance, and sustainability. The limitations associated with substrate compatibility, cost-effectiveness, and sustainability are also critically discussed. Finally, emerging directions, such as green oxidants, heterogeneous catalysis, photocatalysis, and electrochemical methods, are highlighted as promising avenues for future development. This review aims to provide a comprehensive resource to guide the design of efficient and sustainable strategies for synthesizing 1,2-dicarbonyl compounds.
The integration of water purification processes, including photocatalytic processes and membrane technology in the form of photocatalytic membranes, is an effective solution to overcome the operational and performance limitations of both methods in water and wastewater treatment applications. Electron–hole recombination and limited access to light are the primary challenges for photocatalysts in photocatalytic membranes, a field that has garnered significant attention. In this context, incorporating the piezoelectric effect into photocatalytic membranes to form piezo-photocatalytic membranes is a promising approach to improve catalytic performance. This review comprehensively discusses the synergistic interaction between photocatalytic processes, membrane filtration, and piezoelectric effects. First, the fundamental concepts of piezoelectric semiconductors and the working principles of piezo-photocatalytic systems are introduced. Then, preparation strategies for piezo-photocatalysts and piezo-photocatalytic membranes are summarized. In addition, the role of piezo-photocatalysts in enhancing the efficiency of piezo-photocatalytic membranes for water and wastewater treatment applications is critically discussed. Finally, current challenges, limitations, and future research directions in this emerging field are presented. In piezo-photocatalytic membranes, the piezo-photocatalysts are not only optically active but also deform under mechanical stress, thereby generating an electric field. The electric field facilitates the separation of electron–hole pairs in the photocatalytic process and their transfer to the material surface, thereby enhancing oxidation–reduction reactions. These membranes demonstrate enhanced performance compared with traditional photocatalytic membranes, even under low-light conditions, due to piezoelectric activation. Overall, piezo-photocatalytic membranes are considered a promising strategy for overcoming the limitations of conventional photocatalytic membranes under both illuminated and low-light conditions.
Coumarin is a versatile heterocyclic compound with wide applications in the fields of medicines, sensors, fluorescence probes, optoelectronics, and photovoltaics. Coumarin shows fluorescence in the visible region and suitable substitutions with various chromophores make it tunable for applications in the latest (third) generation of solar cells. Dye-sensitized solar cells have profited well with attractive coumarin-based photosensitizers via the various structural frameworks of coumarin, namely D-A, D-π-A, D-D-π-A, and D-A-π-A. The functionalization of coumarin dyes as donors with appropriate fullerene or fullerene-free acceptors is significantly utilized for both binary and ternary blends in bulk heterojunction organic solar cells. This review article pays particular focus to the design, synthesis, and photovoltaic analysis of various coumarin dyes for fabrication in both DSSCs (dye-sensitized solar cells) and OSCs (organic solar cells), reported since 2014.
