Spiro[fluorene-9,9′-xanthene] has received great attention due to its unique structure and possesses wide applications in the field of material chemistry. Herein, we highlighted low-cost, stable and high-performance spiro[fluorene-9,9′-xanthene] derivatives for organic electronics.

Conventionally, N-bromosuccinimide (NBS) is a brominating and oxidizing reagent in organic synthesis. In our research on N-haloimides in organic transformation, we proposed the concept of utilizing N-haloimides like NBS as an amination reagent, i.e., direct incorporation of imido unit to the target molecules to achieve amination, with the assistance of positive halogen(I). In this paper, we would like to summarize the amination of various fundamental substrates with N-haloimides as the amination reagents. We have developed an N-haloimide-DBU (Lewis base activator) combination system, which affords halogen bonding complex and subsequent ion pair intermediate via halogen transfer. All these reactions feature convenient and readily available reagents, mild conditions, simple execution, broad halogen scope, high efficiency and metal-free. The utilization of N-haloimides as versatile aminating reagents has been demonstrated and further application of the synthetic protocol for the preparation of bioactive and optical materials is expected.

Metal-organic frameworks (MOFs) are a new class of crystalline porous materials, having wide pores which provide extremely high specific surface areas, larger than those typically observed in more common porous materials like zeolites or activated carbons. This peculiar property combined with the frequent presence of open-metal sites, makes them very promising for a broad range of applications, spacing from gas storage or separation, drug delivery, toxic air removal, chemical detectors, etc. However, the industrialization of MOFs is still facing difficulties because of their low stability to water or even air moisture, a substance difficult to avoid in applications like those mentioned. Another issue concerning MOF industrialization consists in the low bulk density of the micrometric powder grains, which typically constitute such materials. Unfortunately, their low mechanical stability seems to make difficult even to enhance the packaging by simple mechanical compaction. In this review, we will particularly focus on the current state of art involving the MOF HKUST-1, especially on the degradation process involved when this MOF interacts with water molecules. Furthermore, we will show the connection between water and mechanical stability, bringing to attention of a study where solid tablets of HKUST-1 powder have been realized without any loss of crystallinity or porosity because of an accurate study on the effects of different degree of hydration during the tableting phases. In addition, in order to highlight the causes of damages induced in the framework upon interaction with water, a comparison with other two copper carboxylate MOFs will be shown, namely STAM-1 and STAM-17-OEt, which differ from HKUST-1 uniquely for the organic ligands.

As one of the key components of perovskite solar cells (PSCs), hole transport materials (HTMs)  effectively improve the performance and stability of the devices and greatly promote the development of PSCs. At present, due to the advantages of flexible structure design, simple synthesis, low-cost and abundant raw materials, organic small molecule HTMs have been studied extensively by researchers. Among them, small molecule HTMs with donor–acceptor (D–A) type structures for PSCs have received great attention in the last few years because of their high hole mobility due to strong dipolar intermolecular interactions, minimizing ohmic losses of the contact, good stability, and high solubility. In this review, we mainly introduce some representative D−A−D-type small molecule HTMs, summarize and comment on their properties, and discuss the relationship between molecular structure and performance parameters of devices. Finally, based on the current research, the future design of new efficient HTMs is prospected.

Carbon quantum dots (C-dots) are emerging semiconductor nanomaterials consisting of earth-abundant C, O, and N elements. C-dots have many advantages such as high quantum yield, good photo- and chemical-stability, low-cost, low-toxicity and easy synthesis with earth-abundant precursors. In this minireview, we summarized and updated the most recent research works for the synthesis of the fluorescent and phosphorescent C-dots. In the end, we also give our owner views for the challenges and research directions for C-dots.

Aqueous pollution from industrial dyes and antibiotics has brought up much threat to our daily healthy life. In the present work, hydrogenated black TiO₂ nanoparticles (H-TiO₂) are synthetized, their properties are studied, and their potentials in removing dyes (methylene blue, M.B.) and antibiotics such as tetracycline hydrochloride (TC) and ciprofloxacin (CIP) are explored with the support of statistical optimization. The operational controlled parameters such as catalyst amount (g L⁻¹), pH and irradiation time (min) were optimized using Design of Experiment (DOE) L9 Taguchi Orthogonal Array. From Analysis of Variance (ANOVA) results, it can be seen that irradiation time is the most influencing parameter for % MB color removal, % Degradation of TC and CIP, over catalyst amount and pH. The optimal parameters found here are 0.50 g L⁻¹ of hydrogenated H-TiO₂-750 as catalyst, pH 4 for MB, pH 11 for TC and pH 2 for CIP, respectively. In addition, an irradiation time of 30 min shows a maximum MB color removal of 95.05%, TC 94.8% and CIP 92.25%. Irradiation time is found to be the most influencing parameter (71.08% for MB, 55.33% for TC and 52.77% for CIP) followed by catalyst amount (28.82% for MB, 44.19% for TC and 41.5% for CIP) and in the end pH (0.09% for MB, 0.47% for TC and 5.72% for CIP). With the use of hydrogenated H-TiO₂-750, the dye and antibiotics degradation reaches almost 40% more than using TiO₂ pristine anatase.

The next-generation energy storage focuses on sustainability and renewability, facilitating the process of metal-air batteries and fuel cells. Nevertheless, their performances are suffering from the tardy development of the elaborate design and large-scale synthesis strategy of cost-efficient electrocatalysts. In this work, a convenient strategy for facile synthesizing electroactive material is proposed. As a result, a trifunctional Co/C catalyst is fabricated via a convenient calcination process, utilizing the pyrolysis of cobalt acetate and melamine. The prepared Co/C sample delivers a positive half-wave potential of 0.75 V in oxygen reduction reaction (ORR). Furthermore, the low overpotentials at 10 mA cm⁻² are shown in alkaline conditions for oxygen evolution reaction (OER, 388 mV) and hydrogen evolution reaction (HER, 202 mV). The improved activity is mainly due to the interaction between Co and the in situ formed carbon carrier. The promising trifunctional activities endow the Co/C sample with a bright prospect in metal-air batteries and overall water splitting.

Usually filled with a whey cheese-based sweet cream a few minutes before serving in order to prevent the moisture of the cream from softening the waffle and thus preserve its crispness, Sicilian cannoli are an ancient pastry of Sicily widely appreciated across the world. Another method to protect the “scorza” from quick softening is to coat the inner surface of the waffle with melt chocolate, altering the original taste of the pastry. We now report a simple method to stabilize Sicilian cannoli against moisture migration based on coating the inner layer of the waffle with a thin layer of pure glycerol.